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!

May 092013

The thickness of the pipe insulation hindered the positioning of the rack in the bulkheadThe final item to install within the bulkhead was the wiper rack, which really ought to be very straight forward. However the thickness of the heater pipe insulation I’d used caused problems again. The reduced clearance stopped the entire rack to be fed into the bulkhead as one unit.

After several attempts using different angles/orientations, I conceded defeat and decided the quickest method would be to build the rack in situ.

The obvious issue being that if anything is dropped it could be a real problem fishing it out, now the pipes are all in place.

The two end splined drives were detached from the main rack frame so they could be losely fitted separately. No matter what I tried, I then couldn’t get the central splined drive and main rack frame to fit onto the two ends.

Some head scratching later and my laughable error became clear. I was trying to fit it the wrong way round, with the splined drives facing the screen rather than away from it! Muppet!

An end splined drive reconnected with the main rack frame The wiper rack finally fitted the correct way round!!

Once corrected it, unsurprisingly, fitted without any issues. The final fettling of the adjustable links and connection to the motor will be done once the screen has been put in place.

 Posted by at 9:57 am
May 092013

There’s little worth noting regarding the fitting of the windscreen washer and jets. Fortunately the chromed jets were the first thing I’d decided to install before the bulkhead pipes and wiper rack, which made it possible to fish out dropped washers and wing nuts.

The washer plumbing was left until all the heater and vacuum pipes were in place to avoid it getting in the way.

I managed to succeed in making life hard for myself by putting the washer jets in place and then attempting to fit the washer and wing nut one handed from underneath.

I’d lost count of the number of times I’d dropped either the washer, the nut or both. Finally common sense prevailed.

They could easily be moved and held in position by placing the wings of the nut between the forefingers and balancing the washer on top. The washer jet can then be screwed in from above until it had engaged with the nut, then finally tightened up from below.

My decision to insulate the internal bulkhead heater pipes also caused problems with the routing of the washer piping through into the bulkhead. The heater pipe passes very close to the hole for the washer piping and so the insulation was blocking the way.

Finally, to keep the tubing neat and tidy and away from the moving parts of the wiper rack, it was zip tied to the wiper rack frame.

May 072013

Several weeks ago I’d dropped off a box full of parts, including the heater and vacuum pipes, at the local powder coaters. Rather timely, they were ready for collection just before the bank holiday and one with fair weather forecast to boot! A good chance to crack on.

Fortunately you can’t go wrong with the orientation of the heater pipes and the vacuum pipes are fairly obvious. One vacuum pipe is straight (V2 in the photos) and one has a slight kink (V1) to bypass an entry point in the bulkhead. The entry point was originally blanked off so I assume this must have been for air conditioning or a fitting for LHD cars.

The fitting sequence is also obvious, working from the bottom up: H1, V1, V2, H2 and finally H3. My three heater pipes were new so I’d had a trial fitting of all the pipes and the bulkhead flanges so I wasn’t expecting too many headaches.

I’d picked up three tips from the E-Type forum from others who had gone through the same process:

  • Insulate the heater pipes to stop unwanted heat within the bulkhead
  • Use tape around the flanges to protect the paint when riveting
  • Feed rope or cord through the pipe so, when pulled, it would force the pipe flanges hard against the inside face of the bulkhead

All seemed sensible advice so I purchased some dense foam, pipe insulation. The other issue I’d already found was that the shoulder of the rivet gun was too wide to get the mussel onto the rivet head.

I spent a while looking for alternative rivet guns before someone pointed out the obvious; grind down the side of the rivet gun to reduce the width. A few minutes on a bench grinder and I was all set.

The first of many headaches was that I’d decided to route the vacuum and wiring cable for the EDIS Megajolt ignition within the bulkhead void. So this had to be removed temporarily to provide enough space to work. As I’d previously waxoyled the bulkhead, the whole process was a very messy business!

The tip of feeding rope down the pipes was really helpful. I fed a long length of garden wire down the pipes and, in Heath Robinson fashion, tied the ends behind me. I could then lean back pulling the pipes against the bulkhead while having my hands free for riveting.

Even so, I still managed to miss out the pipe flange when I riveted one end of the first pipe. The exterior flange was securely fixed to the bulkhead while the pipe was free to move!

I ended up cursing the fact that I’d insulated the lower heater pipe. At least I probably should have used much thinner lagging. It made the fitting of the lower vacuum pipe so much harder and later the routing of the windscreen washer tubing.

Even though I’d trial fitted the pipes, when it came to actually fitting them, I had problems aligning the holes in the two flanges and the bulkhead for every single pipe. I’d passed a 3.2mm drill through each hole as the pipes had subsequently been powder coated but still there wasn’t enough tolerance.

I’m also glad I taped the surrounding area as the head of the rivet gun tends to jump off the rivet when the pin snaps. I’m sure I’d have had several chips without it. In fact the only touching up needed was to one of the flanges but this was more to do with the adhesion of the Hammerite to the zinc plating.

Initially I’d only ground down one side of the rivet gun mussel. This was fine for the right hand ends of the vacuum pipes but useless for the gun orientation needed for the left hand side. Rather than stop and grind down the gun, I had a numpty moment and decided to fit the other heater pipes above before returning to finish off the troublesome vacuum pipes.

The pipe insulation was causing issues fitting the left hand side of the lower vacuum pipe so I thought I’d have to remove it. With the heater pipes fitted above there’s was no chance of getting at the vacuum pipes. So I just had to struggle on and finally managed to rivet them in place.

If I had the misfortune to have to do this again I wouldn’t bother with the insulation on the lower heating pipe, I’d waxoyl after installation and only move on to the next pipe once the lower one is completed. At last the long running saga of the bulkhead heater and vacuum pipes was over!!!

Now I can get on fitting the bulkhead components …..

Update: I’ve since read on the E-Type forum that uninsulated heater pipes can deliver sufficient heat to soften the surrounding waxoyl so it becomes runny and can drip everywhere. Therefore it’s probably is wise to insulate the lower pipe after all.

May 022013

I’d hoped to get to a rolling chassis as soon as possible so it was easier to move out into the open to work on. This has became more urgent since the near-disaster when it almost fell off the axle trolley. The front wishbones still need to be machined to accept the modern ball joints so I decided to crack on installing other items that had already been refurbished. Although I was wary of adding too much weight because I was planning to install the engine from below.

I’m leaving the bonnet on for as long as possible. It’s a bit inconvenient but it should hopefully be the safest place. I’d read that it’s possible to fit the radiator with the bonnet in situ as, without the gas strut fitted, it can be opened much further to give sufficient access. The radiator and cooling fans had been ready for some time so I decided to put these on.

The two struts securing the top of the radiator are bolted to small 90 degree brackets on the picture frame. These brackets are held in place by the upper outboard picture frame bolts. What I hadn’t realised was that these bolts can’t be withdrawn because they foul on the front subframe. The bolts and subframe have to be removed together which would require the bonnet to be removed!

Hmmm …. some replanning is required. Once the bonnet and front subframe are removed, it’s only a few more bolts and the picture frame can be removed. The engine could then just be wheeled into position on its trolley and the subframes built back around it.

The prospect of not needing to install the engine from below is very appealing. The main drawback I could see was that it would probably have to be done out in the open for access and I’d need to make sure I could get to a rolling chassis over a weekend.

I’m quite relieved that the wishbones weren’t available earlier. I would have been blissfully unaware that the strut mounting brackets needed to be installed earlier rather than later. I’d only have found out once the engine bay was almost complete. The refitting of the radiator was one of the last engine bay components I would have installed.

I’ll now have to focus on getting as much work done up front as possible, such as fit Ray Livingstone’s Megajolt kit and reuniting the engine and gearbox, leaving the weekend just to:

  • Remove the bonnet, front subframe and picture frame
  • Roll the engine/gearbox into place through the opening
  • Refit the subframe and picture frame …. oh and the brackets!
  • Install the front suspension
  • Fit the radiator
  • Raise the engine onto its mounts
  • Set up the front suspension
  • Refit the bonnet

I suspect I’ll need several pairs of helping hands!

 Posted by at 12:51 pm