Feb 262015

The brakes have been connected and plumbed in for quite a while now. The system only had to be filled with brake fluid and bled, so I had assumed the brakes were essentially complete and wouldn’t be noteworthy. I should have known by now that was almost certainly going to be wildly optimistic …

I had dithered on the type of fluid to use, glycol base or silicone, changing my mind almost on a daily basis before finally making the decision to stick with glycol based DOT4 fluid. The ‘this is absolutely my final decision’ was subsequently reversed to silicone following an interesting article on the subject sent to me by Chris Jackson, whose restoration is being covered in the E-type Magazine.
DOT5 Silicone Brake Fluid

The debate regarding DOT4 (Glycol) verses DOT5 (Silicone) seems to be quite polar in nature. A bit like Marmite – people are either for it or hate it and never the two shall meet! At the time I’d just been working through fixing leaks in the cooling system. Reports of leaks from weeping hoses and splitting repro reservoir bottles are all too common. The thought of brake fluid leaking onto the paint work and remaining undetected paid a significant part in opting for silicone.

However some have raised concerns that silicone fluid might cause rubber seals to swell. Possibly but the composition of the rubber seals has changed over time, with natural rubber no longer used. Modern rubber should now be compatible with all types of fluid.

Automec DOT5 Silicone Fluid

The manufacturer’s blurb suggests silicone fluid is a ‘fill and forget’ solution but I think this is a little wide of the mark as water will find its way into the system. As it doesn’t mix with the brake fluid, it would then pool and cause local corrosion so I’m still planning to replace the silicone fluid periodically, although less frequently than would be the case for DOT fluids.

Apart from the additional expense, the down side of silicone is that, when it is agitated, it has a tendency to absorb tiny air bubbles that are not visible to the eye. This can cause a spongy pedal as the bubbles compress under braking. The simple solution is to leave the fluid to settle overnight before bleeding the system, although that would be more problematic if it ever had to be refilled on a trip.

All the compression joints were checked and tightened. Now the front calipers were bolted to the uprights, sufficient torque could be applied to the bolts clamping the two caliper halves together. Correct torque settings are not published but a brake refurbishing company recommended to torque the 7/16″ diameter bolts to 70 lb-ft and the 3/8″ diameter bolts to 40 lb-ft. I’ll need to keep an eye out for any initial issues.

Remote rear bleed kit

Stevson & Fosseway kits

Another of Chris’ suggestions was to fit one of Fosseway Performance’s remote bleed kits. The standard bleed valves are hard to reach at the best of times, so moving them to a more accessible position on the IRS cage is quite a popular modification. In fact I’d already fitted a similar kit sourced from Stevson Motors prior to installing the IRS unit.

My kit was definitely more agricultural than engineered so I had been a little disappointed when it arrived. The mounting brackets were just pieces of brass sheet that looked as though they had been hand drilled and then bent in a vice.

Still their function is fairly basic and the aesthetics is not a great issue, being tucked up underneath the car, so I had fitted the Stevson kit. It was only later, when I was working underneath the car to re-fit the handbrake cable, did its design start to irk me. My patience was wearing thin after catching the sharp corner of the brass bracket for the umpteenth time.

The revisiting of the handbrake was because I’d routed the cable incorrectly. It should pass through an eyelet on the inside of the transmission tunnel, with a rubber grommet protecting the cable. The cable was too stiff to re-route in situ by disconnecting the cable from the handbrake mechanism. So the entire cable had to be removed.

Re-routing couldn’t be achieved by just disconnecting at compensator linkage Correct routing of cable through grommet in transmission tunnel eyelet

The final straw came when I found that the seat for one of the bleed valves had been machined too far. So the coned face at the end of the valve could never make contact with the seat, let alone form a seal. Longer valves are available … but not in the course thread used in the kit. There was no alternative – it had to be replaced.

I’m sure Stevsons would have rectified the problem but I now had the opportunity of fitting a better quality of kit. An order was placed and the Fosseway kit arrived the next day! The main difficulty was, with the IRS now in place, access was severely limited. The front pair of springs and dampers had to be removed to access the calipers.

Forward rear springs removed for access The Fosseway kit has better banjo attachments Fosseway kit uses sprung bleed valves

The Fosseway kit uses a banjo attachment at the calpiers which is a neater solution and much easier to fit, as it doesn’t require the flexible pipe to rotate when tightening it into the caliper. The other difference is the style of bleed valve used, sprung valves rather than standard solid valves. The sprung valves help with bleeding as the spring stops air entering the system between pumps of the brake pedal. In the end, replacing the remote bleed kit was easier than I had thought and only took an hour and a half.

Brake Bleeding Woes!
This was another task that proved far more troublesome than I had expected. Most methods of bleeding require the help of an assistant. The exception to this is vacuum pumps, such as the Mityvac, which can be operated single-handed. The vacuum is applied to the bleed valve to draw the fluid through the system so both the vacuum and bleed valve can be controlled from one location.

Mityvac vacuum bleeding tool

It was for this reason I purchased a Mityvac pump to replace my old Eezibleed tool. The Eezibleed pressurises the reservoir to push fluid through the system but still requires two people to operate. So doesn’t really offer anything over the traditional method of pumping the brake pedal.

The correct bleeding sequence according to the service manual is the near-side followed by the off-side, starting with the rears and finally moving to the front brakes. The reservoir bottles were filled, the RH reservoir feeding the front brakes and the LH reservoir the rears … let the bleeding begin!

After about 1/2 hour of trying with the Mityvac, absolutely nothing had come out of either of the rear valves. Time for plan B – the Eezibleed was rigged up to the reservoir. All this achieved was pressurising the bottle to what looked like bursting point and spraying fluid everywhere from around the cap. Thank goodness I’d gone for silicone fluid! Still nothing was coming out at the rear calipers.

Plan C! The traditional approach – the good old brake pedal and a patient helper! The resistance started to build after 20-30 pumps of the brake pedal. However this would dissipate after about 30 seconds. Frustratingly there was still no fluid coming from the rears. I suspect pumping the pedal was only pushing fluid into the front circuit and the resistance felt at the pedal was due to the air in the pipe being compressed. Once the pumping stopped the air pressure would force the fluid back into the reservoir.

Stumped, I decided to search the web to find out if there was a specific technique or trick that might help. At least I found out that I certainly wasn’t alone in having trouble bleeding the rear brakes, especially filling a dry system. One tip was to try bleeding the brakes with the engine running as the servo would be boosted by the vacuum. Still no joy!

Another suggestion was to first check the operation of the valve located in the output port of the servo cylinder. Once it had been confirmed fluid was coming out of the servo cylinder, simply loosen the rear bleed valves in turn, allowing the system to bleed naturally, under gravity. Note: the sprung valves need pressure to compress the spring to allow fluid out and so had to be removed for this method

The height of the reservoir above the remainder of the system provides a sufficient head of fluid to allow gravity to do the work for you. Whether the removal and inspection of the cylinder valve had fixed the restriction I’m not sure, but fluid was now coming out of both rear bleed valves.

Success was short lived …. when the brake pedal was depressed, fluid leaked out of the three way union mounted on the IRS cage. The problem was found to be the new flexible Goodridge brake pipe. Although sold as a direct replacement for the E-Type, the rear attachment was too short. It was a similar problem to the remote bleed kit – the attachment could never make contact with the seat and therefore create a seal.

Short end of Goodridge brake hose was too short! The additional mechanical brake light switch

Several days and a new hose later, the system was finally bled. At the same time the last few braking tasks were completed: the brake pedal was much higher than the accelerator pedal and the mechanical brake light switch was fitted.

The height of the pedal is set by adjusting a ‘stop’ screw in the pedal housing, which was set to remove any free travel in the brake pedal. Unfortunately the clutch pedal is too high as well but this doesn’t have any adjustability. Other owners have had the same problem, caused by the push rod being 1/2″ too long on the replacement master cylinders. Another job to the list!

Feb 092015

Even though the engine was started last year, there were a number of outstanding issues and tasks to complete the fuel system. The most concerning was the new fuel tank didn’t fit! At the time, it was just left in situ and the fuel lines connected while the engine was fired up. Refitting had to wait.

Carburetter Overflows
First, however, was the replacement of the three carburetter overflow pipes. At some stage these had been replaced by shorter pipes. Functionally there was nothing wrong with them but they should come together near the oil filter and be held in place by small clip.

The short pipes will be replaced New pipes from Burlen Fuels
Either short overflow pipes had been fitted or the originals had been cut short  New overflow pipes are available from Burlen Fuels – very expensive for what they are!

Everything is available from Burlen Fuels although they offer two lengths of overflow pipe: 19” and 25”. The length of the shorter pipe would have been marginal for the rear carburetter so I opted for 25” pipes …. just in case. With hindsight, 19” pipes should have been ordered for the front two carburetters as the distances are much shorter.

I had decided to replace these once the engine had been fitted. While it would have been much easier to shape them when the engine was sitting on its trolley, I was concerned that guesstimating suitable clearances to engine frames etc would be too easy to get wrong.

Several hours later, ready for fitting The clip securing the ends of the pipes
 Several hours later, the pipes were ready for fitting

The only slight difficulty was the overflow for the rear carburetter as access was limited once it had been shaped. The jury is still out on whether it would have been better to do this job with the engine out!

New bulkhead fuel line
Another fuel problem encountered when the engine was started was the fuel line had gone into the filter housing cockeyed, causing it to cross-thread and leak. The temporary solution had been to reverse the fuel filter however the root cause was the bulkhead section of pipe, which needed to be remade.

These earlier troubles had been caused by a combination of the pipe not being square onto the filter housing and the brass fitting supplied in the fuel line kit. The fitting had an un-threaded shoulder section which then only allowed a turn or two of thread to engage before it bottomed out on the olive. A replacement was found that was threaded to the end.

The vacuum tank needed to be removed to provide sufficient access to offer up the new pipe as it was bent into shape. I wasn’t happy with the original routing of this section of the fuel pipe, as the P-clip securing it to the bulkhead, pulled the pipe hard against the paintwork where there is an ‘X’ indentation in the toe-box.

Original routing Now routed higher on toe-box Upturn no longer fouls bodywork

By inverting the P-clip, so the pipe was supported by the clip rather than being hung from it, the pipe is routed above the ‘X’. The other problem that was cured from my first pipe attempt was the length of the downward run to the union had been cut too short, causing the upturn bend to hit the bodywork.

Installing the fuel tank …. 4th time lucky!
I take my hat off to the original fuel tank fitters, who must have developed quite an efficient technique for getting the fuel tank in place on the production line. Although, with trails and tribulations I had trying to get the tank securely fastened, it was becoming a less daunting challenge with each fitting attempt. Perhaps there is some truth in the joke about E-Types being built up around the fuel tank!

First a few minor tasks were completed. The sump was checked for pinholes as it is prone to corrosion and fitting the missing metal fuel filter at the base of the pick-up pipe. The tank and surrounding bodywork was then covered with plenty of sheets and masking tape to try and minimise the damaging the paintwork.

Fortunately sump was pinhole free Pick-up pipe – now with filter

The initial problem is the aperture of the boot space is less than the width of the seam-welded lip around the circumference of the tank. Tilting the front edge of the tank downwards doesn’t enable the lip at the rear to clear the flange for the boot boards.

There’s a gap in this flange where the boot lock attaches. So the only option I could see was to remove the lock and then tilt the tank sideways, feeding the lip through the gap vacated by the boot lock.

The most obvious approach was to raise the right side of the tank and feed it down to the left since the tank occupies the left side of the boot. However this first attempt failed as the sump attachment is proud of the base of the tank and comes into contact with the floor strengthening sections, halting progress.

So the opposite was attempted, feeding down to the right. The aim was then to shuffle the tank all the way across to the left once the flange had been cleared.

Yet just as it was nearing that point, it fouled somewhere else! It wasn’t immediately obvious what was causing the problem but eventually it was traced to the clip for the boot board. Fortunately it’s only riveted in place and could be removed.

The offending boot board clip Eventually the flange was cleared

Finally the tank was below the flange and could be manoeuvred into position once the various filler and breather pipes were attached. The boot lid drainage pipe caused quite a bit of aggravation as it had a tendency to spring out of place and push the tank away from the mounting points.

Corner bracket should
have captive nut
Breather tubes for
later S2 tanks
So near, yet so far

However, until now, I hadn’t noticed the replacement forward mounting bracket simply had a nut welded to it, rather than a captive nut within a cage. The lack of adjustability provided by a captive nut meant it was impossible to get the distance between the two leftmost mounting points to match those on the tank.

One of the mounting hole in the tank had to be enlarged by around 3mm to get the tank to fit The tank had to come out in order to enlarge the mounting hole in the tank by a couple of millimetres. Unfortunately I wasn’t able to rig up something to measure the difference in centre distances with any degree of accuracy. The tank was re-fitted but it was still a millimetre out, so it was back out for some more fettling.

This time it fitted! Well two of the three mounts did. The third bracket is moveable as it can slide in elongated holes and so would be doddle in comparison. How wrong could I be!

The original bracket had one stud missing and two of the other studs had lost most of their thread due to corrosion. It didn’t feel it was worth trying to salvage it as new ones are inexpensive. So I made the mistake of buying a reproduction bracket – not once but twice!

Damage to original bracket Neither repro brackets were usable

The first wouldn’t fit because the studs were too far apart to mate with the holes in the bulkhead. To make matters worse, I only found this out after it was powder coated. The second was ordered from a different supplier. The studs were in the right place but much smaller diameter. However, as with the previous bracket, they both just had a nut welded in place rather than the captive nut.

This mount requires both lateral and fore/aft adjustability to have any chance of alignment with the bolt. Lateral adjustment is provided by the elongated holes for mounting the bracket. The movement of captive nut provides the fore and aft adjustment. Neither of the repro brackets were useable.

Its times like this that I do get frustrated with all the suppliers – it’s just lazy ‘that’ll do’ mentality and often it would be as hard to get wrong as it would right. Although I really should have spotted the differences when they were purchased. The original one will be repaired, which is what I ought to have done in the first place. Another lesson learnt!

Fuel Sender – stumped but fixed
For some reason the low fuel light on the dash wasn’t working, yet the fuel gauge was fine. The fault was traced back to the fuel sender unit, which has a removable cover plate. So it was easy to gain an understanding of how it worked to control both the fuel gauge and warning light.

W & T terminal mechanisms Low fuel light contact strip

As would be expected, the unit uses a rheostat to vary the voltage drop across the fuel gauge and the warning light is simply a contact switch. However I hadn’t realised they were two completely separate circuits, sharing a common earth – the sender unit housing.

As the float arm rises and falls with changes in fuel levels, its pivot rotates through approximately 80 degrees. Two slider contact arms are attached to the pivot within the unit and therefore follow the same arc. They are also in contact with the sender housing and so are the electrical contact to earth.

Fuel Gauge
One of the sliders runs along the edge of tapered coil of resistance wire which is connected to the exterior T terminal. When the tank is full and the float is raised to its maximum, the full length of resistance wire lies between the slider and the T terminal – a total resistance of 196Ω.

When the tank is nearly empty and the float is at its lowest, the slider will have moved shortening the length of resistance wire between the two. At empty, the rheostat resistance is 18Ω. The fuel gauge is calibrated to display Full and Empty for these two resistance values.

Low Fuel Light
There’s a copper contact strip on the inside of the cover plate which has a small diagonal break in the copper so the two ends are electrically isolated from each other. The W terminal, connected to the gauge, makes permanent contact with one end.

When the tank is full the second slider arm is in contact with the other end of the strip and moves towards the W terminal contact as fuel is consumed. The slider eventually moves across the gap making electrical contact with the W-terminal, completing the path to earth and switching on the warning light.

I couldn’t work out why it wasn’t working. The multi-meter confirmed the internal connections were working correctly. Yet the switching wasn’t evident at the external spade connector. It didn’t make sense as a metal rivet connects the internals with the external spade terminal.

Checking with the multimeter confirmed that somehow the rivet and the external spade terminal were electrically isolated from each other. A dab of solder solved the problem but I still can’t fathom how they could not be in contact with each other.

Once it’s up and running, I’ll fill from empty to find out how many litres of fuel are in the tank when the light comes on.

The tank has since been filled from empty and it takes exactly 12 litres (2.6 gallons) before the warning light goes out. So there should be around a 50-55 miles range once the warning light comes on.

Jan 132015

Jaguar made several changes to the clutch slave cylinder during the production of the E-Type which appear to have caused a fair amount of confusion amongst owners, myself included.

The slave cylinder details from the Jaguar literature are:

  • S1 to engine 7E4606 – short 80mm adjustable cylinder (part C21470)
  • S1 from engine 7E4607 – 95mm hydrostatic self-adjusting cylinder (part C24145)
  • S1 from engine 7E18356 (7E55558 for 2+2) – reverted to adjustable cylinder (part C29801)

The difference being the adjustable cylinders require a return spring and bracket to pull the fork back, so the piston is at the mid-point. The hydrostatic, self-adjusting cylinders must not have the return spring fitted. Either type can be fitted to any of the range, so you just need to know which type is fitted to determine whether to fit a return spring.

As a result, the length of the slave cylinder is often used to differentiate between the two types. A 95mm unit was supplied when I ordered a replacement C29801 cylinder and the suppliers assured me it was correct.

I made the assumption, from all the forum discussions on the subject, that I must have a hydrostatic unit and therefore didn’t include the return spring when it was fitted it to the transmission, prior to installing the engine.

It wasn’t until another S2 owner who was going through the same issue was able to confirm the 2nd version of the non-hydrostatic cylinders was 95mm, not 80mm, with the original Lockheed part having markings 3232 648C. This matched the markings on my replacement cylinder and also on the one that had been removed during the dismantling, which was fitted with a spring.

My conclusion was that the return spring will need to be fitted after all. Another recommendation was to replace the mounting stud by 5/8″ UNC x 1″ socket head bolts. This will make later removal easier as access is severely restricted.

So another task to add to the ‘To Do’ list!

May 192013

While researching the best piping to use for the hydraulics, I’d found out that copper piping is banned in many countries as it is susceptible to work hardening over time. I thought it wise to switch to Cunifer pipes as it is a safety issue, even though I had already purchased a copper pipe kit from Automec.

In the end I took the cautious approach to all the braking system and planned to have the master cylinder and servo units professionally renovated. The main reason being an inspection of the master cylinder had revealed some pitting and I wasn’t confident it would be possible to get a good seal without it being re-sleeved.

Also the fixing studs on the servo unit were all at odd angles so something was amiss. Opening up the servo uncovered a bodged weld ‘repair’ to one of the studs. The servo casing looked as if it had been fractured around the stud and so would need replacing. The units were sent off to J & L Spares to be repaired. However the cost of repairing the master cylinder was more than the cost of a new one so I opted for the latter.

Servo Mounting Studs Bodged repair weld Renovated Servo

The mounting studs for the brake servo were all at odd angles, suggesting all was not well

One of the studs appears to have been bent resulting in a fracture around the stud, whic had been poorly 'repaired'

A renovated servo unit from J & L Spares

Apart from a basic understanding, I’d never really paid much attention to the detailed workings of servo assisted brake systems. So it was out with the Jaguar service manuals to get a better understanding of how the vacuum boost is controlled. It should help if troubleshooting is required later on, especially as I will be tapping into the vacuum circuit for the EDIS Megajolt control module.

It’s actually quite simple. A reservoir tank stores a ‘vacuum’ by being connected to the inlet manifold, which is at a lower pressure than the ambient air pressure. This is then used to boost the braking force when the brake pedal is pressed.

The servo unit contains to volume chambers which are both connected to the vacuum reservoir but separated by a diaphragm. The servo hydraulic piston is operated by fluid forced from the master cylinder but also by a spindle attached to the centre of the diaphragm.

At rest when no braking force is applied, there is no flow of hydraulic fluid and both chambers are at equal pressure and so no force is exerted on the piston.

However when the brake is applied, the master cylinder piston is pushed down the bore forcing fluid from the master cylinder to the servo unit. This operates the servo hydraulic plunger. Near the end of the travel of the master cylinder piston, it operates a reaction valve.

The reaction valve first disconnects the servo’s rear chamber from the vacuum supply and then opens the rear chamber to atmospheric pressure. This creates a pressure difference between the front and rear chambers, which forces the diaphragm and attached spindle forward. Thus increasing the force applied to the servo hydraulic piston.

Once these were installed on the car, it was time for the fabrication of the hydraulic piping ….

The brass fittings were salvaged from the Automec kit and the copper piping used for making mock-ups of the more complex sections. Cunifer piping is typically sold in 25 foot coils which was more than enough. So I had plenty spare ‘just in case’ I made a hash of making the individual pipes.

I now needed to straighten the replacement Cunifer piping and also to obtain a brake flaring tool. Initially I purchased a flarer from Machine Mart which was little short of useless and had the typical Made in China quality about it. I ought to know better by now!

There’s always a number of old, quality flaring tools on eBay but these usually change hands for well in excess of £100. I think people just resell them back on eBay once they’ve finished their restorations, which is what I planned to do. However after being outbid on numerous times I gave up as I needed to press on.

The Oakes brake flaring tool purchased from Automec was well worth the investmentAfter a recommendation, I picked up a new Oakes tool from Automec at the Jaguar Spares Day for a show price of £90. Quite a bit for a tool for a one off job but it does produce good, consistent flares every time. All in all, a good investment and a quality tool.

I’d previously straightened all the copper piping over a form (covered in a previous post) but subsequently disposed of the wooden form, thinking I’d no longer need it!

I did come across a straightening tool produced by a company called Kwix UK which seemed promising. However it only straightens a pipe of a fixed diameter so I’d need three tools for each of the pipe diameters used for the brake and fuel lines.

One to avoid - the Kwix UK pipe straightener - it could be a good product but really let down by their customer serviceThe 1/4″ brake pipes linking the master cylinder and servo run around the engine frames. I thought any slight bends/kinks in these pipes would be more noticeable as they run along the straight edges of the frames. The 1/4″ tool was purchased as a trial and it worked well so I got the 5/16″ one for the fuel lines.

Unfortunately this time, the pipe passed straight through without a hint of straightening and emails to the company received no response. I think they probably just sent the wrong sized tool but couldn’t be bothered with addressing customers’ issues so I won’t be dealing with them again!

The difficulty with bending the pipes was that often it wasn’t possible to trial fit the pipe after each bend was made. The unbent length would usually foul some part of the bodywork, stopping the pipe being placed in situ to mark the exact point for the next bend.

There was little margin for error for pipes that had to be bent in different planes. It only takes slight errors in the position of the bend, the angle of the bend or the plane in which the bend is made for it not to fit and the errors are magnified once another bend or two is added.

The clutch and rear brake piping, although the photos don't quite capture the various bends in numerous different planesThe mantra measure twice cut once applied here as, once bent, it’s almost impossible to re-straighten a pipe, especially the larger diameter piping. In fact it was more like measure 10 times, bend once! I probably had to discard just under half of my first attempts.

Having completed the hydraulics, I’m not convinced of the wisdom of purchasing kits as it would be nigh on impossible to get all the pipes right first time. So I’m glad I decided to fabricate my own pipes and it was quite therapeutic.

Having said that, I still managed a few numpty moments. A couple of times I allowed the brass fitting to slide away from the flared end onto the wrong side of where the bend was then made. Another scrapped length of piping!

The copper kit didn’t go completely to waste as it was cut down into shorter lengths and used to get correct position, angle and plane for a small section with say 2 or 3 bends. This could then be offered up without fouling the bodywork before making the same bends in the full length of pipe.

I had all but a few of the original pipes to use as templates however I did deviate in a couple of areas:

  • The pipe to the rear runs along the under floor box section but divert so it is clear of the mounting bolts for the torsion bar reaction plate. In doing so I think the pipe would be more exposed to damage. I continued running along the box section and will just need to take care when doing up the torsion plate bolts.
  • I thought it looked neater having straight piping around the front of the engine frames rather than trying to get them to mirror all the rises and falls in the frame profile. Therefore, just before the front brake union, the smaller front brake pipe jumps over the larger pipe rather than underneath.

Also my pipe bender couldn’t get as tight ‘U’ bends from the brake and clutch master cylinders and other methods were prone to causing the pipe to start collapsing.

Hydraulic Pipe Routing
Below are a few photos of the trial fitting of the various hydraulic pipes on the S2.

Clutch from Master Cylinder Clutch low pressure pipe

The routing of the clutch piping from the master cylinder to the flexible hose union. Note - not fitted at this stage is the P-clip on the LH frame bolt, securing the pipe

The clutch low pressure hose has a tight U-bend before running parallel with the engine frame

Brake – Master to Servo Brake – around Picture Frame Brake – Master to Servo & To Front

The brake pipe from the master cylinder to the servo unit also has an initial tight U-bend before running down the diagonal, round engine frame

The pipe then routes around the bottom of the picture frame to an inline union

From the union, the pipe travels up the opposite side frame member to the servo unit.

Front feed over Master to Servo Left Front Brake Righr Front Brake

The feed fro mthe servo to the front brakes first passes underneath the thicker master to servo pipe and then over it to the front union

The left brake pipe from the front union

The right brake pipe from the front union

Servo to Rear Union Union to Rear A few off cuts!!

The path of the pipe for the rear brakes from the servo to an inline union, which includes the brake light hydraulic switch

From the brake light switch union, the rear pipe passed down the LHS of the underside of the car

The fitting of the clutch and brake pipes was definitely a case of practice makes perfect - a few off cuts!

Jan 232013

The brake reservoir caps house electrical connections for the float operated switch for the brake fluid warning light and appeared to be quite corroded. It was only once they had been opened that it became clear that what I thought was corrosion was probably crystallised hydraulic fluid.

Both the reservoir caps appeared to be corroded but it was actually crystalised hydraulic fluid This was most of the contents of the first reservoir! The second reservoir was not much better!

The float should be enclosed in an aluminium cylinder but most of this had corroded away. I had little option but to replace the reservoirs which was a shame. Replacements are readily available however an alarming number of people had reported problems with them splitting and the resulting leak causing havoc with the paint work.

Reading other people’s woes with the repro products, I think the splitting might be initiated either when the black low pressure rubber tubing is pushed on, as a reasonable amount of force is required, or by over-tightening the hose clamps. Basically the new parts are not particularly good quality and no doubt originate from China.

The original bottles had a metal insert inside the supply protrusion/outlet which would avoid the over-tightening issue. The insert also had a gauze nylon filter, again missing from the new ones.

The clutch reservoir was better as the fluid hadn’t crystalised, which I’m now thinking might be caused as the aluminium float shroud corrodes. However there was a lot of gunk at the bottom so I thought it wise to replace as well.

Reservoir cut open to retrieve the metal insert

I decided to salvage the metal inserts by cutting the bottles in half. These were zinc-nickel plated along with the bracket clamps before being inserted into the new bottles. The method I use to insert them was to pass a piece of string through the supply outlet to act as a guide.

A rod was then used to carefully push the insert home while supporting the other side to minimise the stress on the plastic bottle. The reverse was done when pushing on the low pressure rubber tubing, opposing the pressure with the same rod. Hopefully it will be ok.

I couldn’t work out a method of refitting the nylon gauze filter on to the metal insert once it was in place. The filters were not in the best of shape so they have been omitted.

Brake and Clutch reservoirs reunited with re-plated bracket Brake Servo reservoir showing the aluminium shroud around the float

However this does lead on to my next dilemma. As the calipers have been reconditioned and the reservoirs and hydraulic pipes replaced, I have the opportunity to switch from DOT4 to silicone brake fluid.

I like the idea of using the silicone fluid to avoid potential future problems with leaks damaging the paint work, especially in light of the problems others have had with the new reservoir bottles. Conversely there are views that the rubber seals can be damaged over the long term by the silicone.

It seems there isn’t a general consensus on which is the best way to go and it’s difficult determining whether advice is based on fact or merely that the person went down that route themselves and therefore it must be the right choice! Hmmmmm ……

Jun 172012

The fuel and brake lines were other items that were to be replaced as a matter of course during the rebuild. I had intended to purchase lengths of piping and make the individual pipes myself. However the cost of decent pipe flaring tools, able to achieve consistently good joints, are considerably more than complete kits.

So I’d purchased a brake kit from Automec, a similar fuel line kit from Hutsons and a pipe bending tool. Both kits were supplied in copper rather than bundy or cunifer which is closer to the original look. So I’ll have to see how they look on the car and I may revert to fabricating my own in cunifer; an alloy of Copper (Cu), Nickel (Ni) and Iron (Fe).

More importantly, I subsequently found out that copper brake pipes are banned in countries like Australia and the US, where cunifer is the norm. Apparently the copper pipes are susceptible to work hardening over time which can lead to fracturing. The introduction of Nickel and Iron addresses this problem. I think more research is needed especially as it’s a safety issue.

Back to the pipes … the problem with the kits is that they are fabricated from coiled piping. In order to get neat, straight pipe runs they need to be straightened before forming into the correct shapes.

I found an article on an American car site with a rather over-engineered process for straightening coiled fuel pipes. I had a spare afternoon so I thought I’d give it a go. The main point is that the coiled fuel pipe should only be straightened/bent in the same plane as the direction of the original coil.

The first step is to lay the coiled pipes on a flat surface and uncoil them against a straight edge, therefore ensuring additional bends in other planes are not introduced. Once released, the pipes will spring back to some extent in the direction of the original coil so the pipes will now form an arc.

Trial run with the shorter engine bay 5/16″ fuel pipe

Long boot to engine bay 5/16″ fuel pipe

The second step involves deforming the pipes beyond a straight line so that this time, when they spring back, they (hopefully) return to a straight pipe. As it happens, the pipes need to be bent beyond the straight line to exactly the same radius as the arc of the now uncoiled pipe.

I used two pieces of old shelving and some 9mm cladding, the latter would act as channel down the centre of the form. I guess you could just use one board against a flat surface.

The radius of this arc is determined by the pipe thickness and the diameter of the original coil. Therefore, for a given pipe size from the same original coiled length, the arc radius will be the same regardless of pipe length.

The final step is bending the arced pipes over the form. Starting at one end, position the pipe arcing away from the form but in the same plane. Then bend the pipe around to produce a straight pipe when released. However be careful not to allow the pipes to rotate when doing the final step.

I thought the results were quite good for a pleasant afternoon spent taking a sledgehammer to crack a nut!

Apr 242012

I was surprised how rusty the clutch pedal and pedal springs were seeing it’s inside the car and underneath the aluminium pedalbox housing. I’m assuming this must have been as a result of condensation. Once it’s complete I’ll give the inside a covering of ACF50 to give it some protection. There’s nothing worth noting on the dismantling as the pedals simply rotate on a shaft through the pedalbox.

The pedalbox was renovated before I’d come across the company that ultrasonically cleans alloy components, so it was shotblasted and then coated with a lacquer product sold by Eastwood to stop surface oxidisation. The pedal arm, foot pads and springs were also shot blasted and then powder coated.

The rebuild was fiddly mainly because the pedal springs are quite strong so it’s difficult to align everything while pushing the shaft into position. The final washer had a tendency to drop out at the final moment! It made sense to cover the shaft and mating surfaces in plenty of grease.

I was surprised that the brake light switch is actually part of the hydraulic system, actuated by hydraulic pressure when the brake pedal is pressed. Some have reported problems with the response of this switch and have therefore either replaced it or supplemented it with a mechanical microswitch operated by the brake pedal.

While the car is apart and the looms are being put in place, it makes sense to install both a hydraulic switch and a microswitch in parallel, to build in redundancy. All it would require would be to fabricate a bracket to hold a microswitch in the pedalbox housing. I’ll do this as part of the final electric fitting when the lights are installed.