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 252015
 

The installation of the fuel tank had taken a number of fitting attempts and required the enlargement of one of the mounting holes. The toing and froing had inevitably resulted in a couple of light scratches inside the boot space. So I decided to remove the tank for a final time to paint the exposed metal in the mounting hole and touch up the scratches.

The tank was completely wrapped in sheets before extracting it to avoid further scratches. As it was being lifted clear the sheet snared on the corner of the flange for the boot boards, stopping the tank in its tracks and putting me off balance …. the tank came down on the rear wheel arch!

Even though it was the lightest of landings, the weight of the tank was sufficient to put a dent in the wheel arch. It was less than a 1cm long but, as its on a double curved surface, it stood out like a sore thumb. Absolutely gutted!

Even though it’s a small dent, your eye is drawn to it The irony of it all: it’s hard to photograph!

The only saving grace was the sheet had offered some protection and the paint wasn’t damaged. I’d seen companies offering a paintless dent removal service. It had to be worth a go so I contacted a guy operating under the name Dr Dent.

His toolkit appeared to consist of a vast number of levers in all shapes and sizes which are used to press out dents from behind. A couple of minutes later (most of which was spent chatting!) and he was out with the polisher – job done! Even right up close, I can’t find where it was dented. Needless to say I would thoroughly recommend him if you’re equally careless!

Good as new! Chuffed!
Feb 102015
 

The green illumination of the dash gauges is achieved by plastic green filters within the gauges. However almost all of these filters had deteriorated due to their proximity to the incandescent bulbs. Some had actually melted due to the heat produced. I had therefore decided to ‘upgrade’ to LEDs after reading the conversion on the E-Type forum. For my conversion, I wanted to:

  • Retain having two brightness settings: Bright and Dim *
  • Switch between green and blue lighting

* – I couldn’t envisage a situation when I would want the side/head lights on but the dash not illuminated. So I have decided to drop the ability to turn off the dash illumination and have replaced the 3-way Panel switch with a 2-way switch.

Dimming the LEDs
The RGB LED strips have a common 12 volt supply and then one wire for each of the primary colours. The LEDs for a specific colour are turned on by connecting the corresponding wire to 0v, ie earth.

The amount of light produced by incandescent bulbs is linear to the current flowing through the bulb. Therefore accurate dimming of the bulbs is achieved by switching a suitably sized resistor into the circuit, in series with the bulbs.

Unfortunately this task is not as simple with LEDs. The light output for two ‘identical’ LEDs is not as predictable simply by reducing the voltage drop across them. The only reliable way to dim LEDs is rapidly switching the LED on and off. Above a certain switching frequency, the human brain cannot differentiate between when the LED is on and off. The perceived brightness is then the relative percentage of time the LED is on during one switching cycle.

Fortunately it’s possible to purchase small LED control units to perform this function. My initial trials using LEDs found that, without on/off switching, the light output was too great. Therefore two LED control units would be needed to control the brightness for both the Bright and Dim settings.

The other key difference, already mentioned, is that the 12v supply voltage is always connected. The individual LED colours are turned on by connecting their earth lead to a ‘floating earth’.

Note: this ‘earth’ is different from the car earth as when in dimming mode it will switch between 0v and 12v.

Green/Blue switching
The ability to switch between green and blue lighting would require the complete rewiring of:
i) the panel switch to select either the ‘Bright’ or ‘Dim’ earth connection from the respective LED control module (rather than provide the 12 volt supply)

ii) the spare switch to then connect the selected earth to either the green or blue lead. After a few trials, I settled on the wiring diagram shown.

Both LED control modules are connected to the loom’s Red supply wire from Fuse 5, which is disconnected from the Panel Switch, and the car’s earth. The positive LED outputs from both control modules provide the 12v supply to the RGB cable.

New wiring is then needed to between the two switches for the earth connections to either the Blue or Green LED lead. Finally the gauges and switch legend LED strip are daisy chained together with 4-core RGB cabling.

Switch Legend Strip
The switch legend is normally lit by three bulbs mounted in convex reflectors approximately 10cm in length. The green hue was achieved by a plastic green tape glued to the rear of the legend strip. However this has faded so it was now more of a mucky yellow colour. The tape was removed as the colour would now be provided by the LEDs.

Green tape provided legend colouring LED strips fitted to legend reflectors
The green colour of the backlighting was obtained by a coloured plastic strip Installation of the LEDs for the illumination of the switch legend.

{Note: the dash photo was taken midway through being cleaned/treated with Gtechniq Trim Restorer C4 – hence the half and half look!}

Dash Gauges
The seven gauges are all opened by rotating the rim until tabs on the rim align with cut-outs in the housing. This enables the rim and glass to be removed to install the LED strips.

The internals of the smaller four gauges (water temperature, oil pressure, fuel and battery) are very similar where the mechanisms are permanently secured to the housing. These mechanisms are quite delicate so the dismantling and insertion of the 10cm LED strips needed to be done with some care.

These gauges have a face plate which has to be eased away from the underlying cup, which has the gauge’s scale printed on it. A small screwdriver can then be inserted under the rim of the cup to prise it away from the housing. Once loose, it’s a matter of rotating the cup to clear the fragile needle.

Six dash gauges and clock Face plate & cup removed LED strip inserted from the rear

It’s very easy to inadvertently solder the RGB earth contacts together so it was well worth testing the operation of the LEDs before rebuilding the gauges.

The clock proved to be more difficult even though the entire clock mechanism comes out with the face. It’s slightly larger than the other gauges and so can accommodate a 15cm strip. However the clearance between the housing and the clock mechanism wasn’t sufficient due to the clear, waterproof coating. This had to be peel off to fit.

Removing the waterproofing Cabling was a tight squeeze Comparing brightness of colours

The entire mechanisms for rev counter and speedometer are also removed with the gauge face, which allows unhindered access to stick the 35cm strip to the perimeter.

Rev counter housing Cable pass through bulb opening Testing prior to rebuilding

The downside of having the ability to switch between the two colours is it requires multi-core cable and so the installation is not so discreet. Even so, it will all be hidden from view once in place.

My first attempt was to use standard RBG cables and connectors but these provide to be temperamental and unlikely to stand the test of time. I therefore changed them to larger plug and socket terminals with internal, mini spade connectors which were also held together by a clip.

RGB connectors were unreliable Blue illumination without dimming Switched to green illumination

The other LED lighting was to illuminated the boot when the bootlid was opened. Two 25cm pure white LED strips were stuck to the underside of the tonneau top panel. Power was provided by running a wire from the permanent Brown fuse terminals and switched by a micro switch attached to the boot hinge.

Would I do the same upgrade again? Definitely not! Possibly just installing a single colour LED strip but the ability to switch between green and blue lighting resulted in unnecessary complexity. Just because it can be done, doesn’t mean it should be done!

 Posted by at 8:43 am
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.