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.

Jan 292013

Even though the pipe end centres were 6mm too wide, there wasn’t sufficient flex in the pipe to ‘persuade’ it to go in. When I originally measured the centres distance of 22¾” (578mm), the accuracy of the measurement wasn’t helped by the fact that there wasn’t a clear line of sight between the holes on the bulkhead as the engine stabiliser bracket is in the way.

At least the fabricated pipe could now be used to obtain an exact spacing of the bulkhead holes. The pipe was cut in half, shortened and a dowel inserted. The two halves could then be adjusted on the dowel to fit the bulkhead. The correct centres distance was 3/32” shorter than my original measurement …. ooops!

A while later, the MkIII heater pipe was dropped off …. would it fit and would the saga be over?? As soon as I got back from the office I dashed into the garage to trial fit the new pipe. It was spot on, much to the relief of all concerned!

A mock up of the bulkhead was made in aluminium sheet to ensure everything would fit this time around

It was suggested to re-title the blog entry to ‘How my F1-engineer-mate made a bl00dy great meal of remaking a simple water pipe’. The irony is even that was too long for the blog title field! Anyway, the reason the first pipe didn’t fit was as much down to my inability to use a tape measure as it was in the fabrication.

The photo shows the difference in the bend radius between the two pipes. The tighter bend in the MkIII version means the pipe is perpendicular where it passes through the flange.

The heater pipes are one of the first items that need to be installed on a rebuild so I was looking forward to fitting them at last and cracking on with the rebuild.

I should have known better …. the collar on my rivet gun is too wide, so it fouls on the protruding pipe and can’t reach the rivet head! How can something a simple as a heating pipe cause so much grief?!?

Oct 112012

Wiper arm spline driveThe general consensus from people who have gone through a full rebuild is that one of the first tasks is to fit the various pipes and components within the bulkhead, before access becomes too restricted. So I set to work on the wiper rack. It was working fine but had started to show signs of rust so I decided to smarten it up. Yet again, in my enthusiasm to press on, I forgot to take some decent before photos. The only difficult part during the dismantling was the removal of the rear brackets from the three splined drive assemblies, which needed to be pressed off. The rest of the parts were simply secured by nuts or circlips.

Splined wiper blade drives - the central drive (uppermost) has a spacer between the drive and the rear bracketThe wiper arm splines on each of the three splined drives weren’t in the best of shape but were still serviceable. Which is just as well as the only replacement I could find was for a fully remanufacturer rack. Due to the shape of the rack, the central drive has a longer shaft than the outer two and so has a spacer fitted between the drive and the rear bracket.

With the exception of the angled bezels and chromed parts, the individual parts followed the now standard cleaning process: immersion in a citric based rust remover overnight, wire brushing, zinc plating/passivation and finally coated with Gtechniq S1. Meanwhile the outer bezels and retaining nuts had been sent off to be chrome plated.

The synchronisation of the rotation of the three splined drives is achieved by two connecting rods, with the central drive also having a connecting rod to the wiper motor to provide the drive. At each rod end is a ball-joint fitting which is secured by a small, horseshoe shaped, snap-lock clip shown below. Unfortunately one of the tiny snap-lock ‘ears’ made a break for freedom and, despite a hands and knees search of the living room carpet, was never to be seen again! The only option available was to purchase a complete socket unit which included the clip and the inevitable robbing by the E-Type parts suppliers!!

Original & new snap-locks Wiper rack components Reassembled splined drives

The original snap-lock clip on the right and the rather expensive complete socket unit, on left

Wiper rack parts plated and chromed, ready for the rebuild

Rear brackets reassembled onto splined drives

The connecting rods are connected to the central wiper drive by a series of spring washers, nylon guides and secured with a circlip. All very straight forward. All that remains is to fit the rack and connect the central drive to the wiper motor. I think it will be necessary to fit the washer jets and tubing before the rack as there’s not a lot of room in the bulkhead.

Refitting parts order Connecting Rods refitted Completed wiper rack

Apr 242012

As with all the other electrical units, the alloy parts were was ultrasonically cleaned and then sprayed with Gtechniq S1 SmartMetal while the other steel parts were zinc-nickel plated. The next two tasks were to sort out the gearbox lid which had been distorted and also to strip and paint the yoke.

The offending motor gearbox lid after several attempts at heat shrinkingThe centre area of the gearbox lid has been stretched at some point. Therefore its outer perimeter no longer made a continuous seal and so would allow water into the gearbox housing.

The suggested solution was to heat shrink the centre section of the lid to reverse the deformation – heating the centre of the lid to near red heat and then rapidly cooling. After several attempts of heating the lid with a gas blow torch and cooling using a can of compressed CO2, all I succeeded in doing was to work harden it in exactly the same shape as before. Aaaaaaargh!

It probably needs to be heated to a much higher temperature using oxy acetylene. In the end I cheated to avoid holding up the rebuild and obtained a replacement lid. When I get time I’ll give it a proper go at flattening the lid, as I would like to keep the original with the correct stampings.

The wiper motor yoke painted in silver hammerite .... at some point I'll repaint in the correct colourNext up was the yoke which contains the two permanent magnets. The magnets can be removed by lifting the retaining clips so the yoke could then be shot blasted before being painted in silver hammerite. I was quite pleased with the finished article even though the silver hammerite was not quite the correct colour.

During the refurbishing of the cooling fan motors I had found a dark silver hammered paint from Rust-oleum, which is very similar to the orginal colour. At some stage I will re-paint the round bodied yoke but decided to put it off for now. Mainly because of the difficulty I’d had getting a good finish with the Rust-oleum product.

Fortunately the armature wasn’t in such a bad state as those in the cooling fan motors and so all that was required was some light wire brushing and polishing before the S1 SmartMetal coating. I had investigated the availability of new brushes and parking switch units but these seemed to be rather difficult to get hold of. Therefore when I spotted a ‘new, old stock’ brush unit for sale I thought I’d get it as a spare for the future. However I’ve not yet found anyone who can supply the parking switch units.

Cleaned armature Triple Brushes Wiper Motor Parts

The armature was wired brushed to remove the worse of the rust. It was then polished and finally sprayed with Gtechniq S1

The armature brushes and parking switch unit

The wiper motor compentent ready for the rebuild, including the spare armature brushes unit

The rebuild starts with installing the armature brushes and parking switch unit, as these are wired together. The brushes are secured by three small setscrews and the connecting wiring passes through a notch in the motor gearbox housing.

The parking switch is secured by two setscrews from the inside of the gearbox compartment, as shown in the middle photo below. This also shows the protruding parking switch plunger which is activated by a cam on the underside of the gear wheel. The cam positioning is such that it operates the switch when the wiper blades return to their normal rest position.

First fit the brushes Parking switch attachment ACF50 applied to Yoke

The brushes and the parking switch unit are the first to be fitted

The parking switch is attached by two setscrews from inside the gearbox housing. Note the switch plunge which operates when the wipers return to their normal rest position

The interior of the yoke was sprayed with ACF50 which provides a good protection from moisture

After several attempts at fitting the armature and yoke, I found it easier to first fit the armature into the brushes and motor gearbox and then fit the yoke. With this approach its was necessary to hold the armature’s worm drive from within the gearbox so that, when fitting the yoke, the yoke’s magnets didn’t pull the armature out of the brushes. Also don’t do what I did and forget to fit the plain washer between the armature and motor gearbox housing!

Care was also needed in making sure that the thrust and fibre washers were correctly seated in the yoke bearing housing. The easiest way to do this was to join the two with yoke positioned so the ‘bearing’ housing was facing downwards.

Initially I tried to put the armature into the yoke and then attach them both to the motor gearbox. However the problem was it was then difficult to withdraw the three sprung brushes at the same time as inserting the armature, because the yoke restricted access to the brushes.

The middle photo below shows the arrow head marking on the motor gearbox and a corresponding line on the yoke. These need to be aligned when refitting. Also shown is the threaded armature stop. This was then screwed into the gearbox housing until it touched the nylon cap on the armature shaft, before being backed off a 1/4 of a turn.

Next fit the armature Alignment markings Belleville washer goes here

The brushes were then withdrawn to allow the armature to be inserted

The markings on the motor gearbox housing and the yoke must be aligned when re-fitting

The Belleville washer provides pre-load for the armature shaft

The Belleville washers is then positioned within the gearbox before inserting the geared output shaft. The rest of the gearbox was then filled with grease before the output rotatry link and gearbox lid were refitted. The rubber moulding sealing the output shaft area had hardened and split.

At the time I dismantled the motor, it was one of the few parts that wasn’t being remanufactured. Probably because it was only used on the Series 2. However by the time I has started the rebuild, one of the suppliers had made a small batch so I decided to grab one while still available.

Re-packed with grease Output rotary link Motor rebuild completed!

The geared output shaft (just about visible) was inserted and then the remaining space packed with grease

The output rotry link was refitted which also secures the geared output shaft. Although I'd forgotten to insert the rubber seal first .... so I'll have to refit it

The completed wiper motor

The only thing that remains is to adjust the various wiper motor & rack linkages which can only be done once they’re installed in the car. People usually leave the installation of the windscreen until the latter stages of a rebuild. I guess this is because it would restrict access to dash area. However I’m tempted to install the windscreen as soon as the dash wiring looms and dash panels are in place. Therefore I’ll be able to adjust the linkages before the bulkhead access become restricted.