Pressure Regulator - Stripdown and Rebuild

As far back as 2015 I'd given the pressure regulator from my car a refresh, though I hadn't really given it a good going over. The chamber on the side that the HP pump pipe connects-to was made of plastic, so I removed it before using a wire wheel to de-rust the metal body.  

From my DS: Plastic Side Chamber - 19 July 2015

I put the two parts back together and gave it a spray of paint - that was it really........

......Only that plastic side chamber had always niggled me. I hadn't expected it to be plastic.  I was worried it might snap at the hose union. All my research showed that a DS pressure regulator had a metal side chamber. If it wasn't intended for a DS, then was it set up for the right pressure inside? 

At the 2017 Citromobile rally in Holland I found an all metal regulator - still fitted to a DS mounting bracket -  for a few Euros so snapped it up. 

I decided to strip and rebuild it for the learning. Then I could decide whether to use it on my restoration or not. More recent research turned up a photo of a regulator with a plastic body - being sold as a replacement for a Citroen BX. If that was so, then I definitely wanted to use this new pressure regulator.

Spot The Difference

Instructions for stripping and rebuilding the pressure regulator can be found in Operation DX. 391-6 in manual 518 although, being the earlier manual, it deals with the earlier aluminium bodied regulators which have a distinctive screw cap. If your car has one of these, then all advice is to seek to replace it with a later steel-bodied one. You really need to seek out a copy of volume 3 of French language manual 583 for the more up to date Operation D. 391-6. You can find the link to it on another tab on the 'workshop manual' tab of this blog.

There is also a very handy two part 'DSSMPassion' video on Youtube. Here's the link to the first part.

Pressure Regulator - strip down video part 1

I bought a rebuild kit from Citroen Classics. this consists of a few rubber 'O' rings and two new ball bearings. The kit from Der Franzose is similar but includes two new springs. That might be an important consideration, as it's the springs that do all the work and get 'tired'.

Removing the side chamber revealed a load of sludge.

Slide Valve and Sludge - 18 February 2018

There was also an 'O' ring to fish out.....

The shiny bit in the middle is the domed end of a slide valve. It has a circlip on one end that stops it moving completely through the passage. I removed the valve with a gentle squirt of compressed air down one of the hydraulic pipe shafts.

Slide valve

I removed the large bolt for depressurising the accumulator. Hidden behind this is a ball bearing. In the end that the accumulator sphere screws to, there is a small 'U' shaped bracket held in place with a bolt.

Removing the 'U' bracket revealed another ball bearing.The dull grey circle in the middle is the flat end of the other slide valve. This was removed with a squirt of compressed air

The 'DSSM' strip down video makes reference (at the 2:09 mark) to the workshop manual technique for removing the end cap. You won't find it in manual 814. (814 doesn't include any information on stripping the pressure regulator). Unusually won't find it in manual 518 either! You need to search out a copy of volume 3 of French language manual 583 and look up the later pages of Operation D.391-6. You can find 583 by following the link to the "Tony Jackson" dropbox site. Details of this are in the 'workshop manual' tab of this blog.

The end cap covers a powerful spring and is held in place with a circlip that locks into a recessed groove. Because of the recess, this is near-impossible to winkle out once it's been fitted and painted over..... The technique is to drill a small hole through the side of the body  in line with the recessed channel that the circlip sits in, and then to insert a pin to compress the end of the circlip. This then gives you enough purchase to lever it out.

By looking at the circlip, I marked my drill point to be in the gap of the circlip. I didn't want to drill through the circlip! That's true, but as I wanted to drill on the back, unseen side of the body I actually rotated the circip with a screwdriver blade so that the gap would be where I wanted it to be. The manual says  to use a 2.5mm diameter drill to drill a 'keyhole' 4mm in from the edge - inline with the groove the circlip sits in.

Drilling a 'Keyhole' to release the Cap Circlip.

With the hole drilled, I rotated the circlip so one open end of the circlip was just over the hole. With one of the long mounting bolts for the pressure regulator in the end cap (a long bolt meant I had working room between the jaws of the vice), I used a vice to compress the end cap just enough to take the pressure off the circlip. 

Pushing the flat end a twist drill through the hole I'd drilled, I was able to press down on the circlip edge to free it from it's recess, and then get a small screwdriver blade underneath it. It was soon out.

Cap and Spring Compressed. Circlip Removed - 18 February 2018

I slowly opened up the vice, being careful to not let anything fall out of the end of the regulator. I laid out the parts so I could see what i was dealing with. The ginger nut was not part of the assembly. 

With the spring removed from the end cap, I discovered a number of thin shims. 

Closer inspection revealed more shims in the end of the side cover I had removed earlier. All had been difficult to see as they were covered in black sludge.

I assume that it is the number of shims that are used to set the operating pressure(s) of the regulator?

Since my kit didn't include replacement springs, I pulled apart my other regulator (why not!) and compared spring lengths. They seemed to be consistent - meaning that either both sets were worn and compressed to the same degree - or neither were.

All parts were carefully cleaned without abrasives. The body was washed in Jizer and rinsed, and all the passage ways were blown out with compressed air.

The regulator I was rebuilding still had some Citroen codes and maker marks on it - so was the original colour. I was keen to see how the paint colour I used back in 2015 compared to the colour of an original. It was close but not a perfect match. I wasn't fussed as the colour of the 'original' was different to other 'original' parts I had too!

Comparing Paint Colours - original and my first respray

I cleaned the body with paint stripper and on a wire wheel before treating it with phosphoric acid. I was careful that none went anywhere near the slide valve bores. I gave the body an initial paint up before re-assembly

Here's the rebuild video from "DSSMPassion":

Pressure regulator - rebuild video

The seal in the cap was lubricated with LHM and replaced as was the seal on the de-pressurising bolt. I masked the threads of this bolt with tape to enable me to slip the 'O' ring over them without tearing it.

Replacing the seals was the secondary purpose for this strip down. Other than a flat accumulator sphere, the main reasons for a poorly performing (very low cycle time between 'clicks') pressure regulator is wear between the slide valves and their shafts. My strip down would not tackle this but would, at least, enable me to clean out any sludge and to make sure all parts were free to operate as intended. 

The ball bearing in the body was replaced, as was the one behind the de-pressurising bolt. All the parts were re-assembled and lubricated with LHM. I used a vice to compress the cap into the body - being careful not to pinch the sealing 'O' ring. The circlip was replaced and the vice opened up.

All apertures were blocked once more, before I gave it a final coat or two of paint.

Just for the hell of it, I tried a different colour on my first regulator (left hand one in the photo below)  - but it looked wrong.

I stuck with the original colour I'd chosen for my hydraulic parts - BS 226 - on the right in the photo above.

With the mounting bolts zinc-plated, it's all ready for the refit!

Starter Motor Rebuild - Ducellier 6182A

There are a number of jobs you should take the chance to do while the engine is out - like making sure your starter motor is going to serve you well in the future. A good place to start is with a replacement of the starter motor brushes.

Although my car had been laid-up for many years, I was confident that the starter worked consistently - even if I couldn't get the engine to fire in those first few weeks! Like many things, I tacked this job from the point of view of 'opportunistic maintenance'. However my starter looked very tired so was going to benefit from a good spruce up anyway.

A Tired Looking Starter

The Terminals Were Very Rusty

With my engine build underway, now I had the time to tackle the starter and set to work on some research:

You can find the basic instructions for removing a solenoid in Operation D.533-2 in Section 3 of Volume 2 of Manual 814. However it doesn't cover a full overhaul.

I found a very useful three part video that covers the full strip down and rebuild procedure. Although the starter featured in the video is a Ducellier 6201A, it's close enough to mine to prove very handy. You can find the first part of the video here:

Ducellier 6201A Rebuild - Part 1

I also found a very useful picture guide to rebuilding a Ducellier 6200A on the 'HD19' site:

Ducellier 6200A Overhaul

(When you are there, click on 'Restauration' at the top, then when the page loads, click on 'Emises En Etat Des Organes Mecaniques electrifies ornamentation' at the bottom).

I set to work. The first step is to split the starter. I disconnect the wire between the starter body and the solenoid/ relay piggybacking on top. I removed the two nuts from the domed bearing back cover plate. From the nose of the solenoid, I unscrewed the four small screws and removed the central cap. Some are a simple rubber grommet, mine was a threaded metal cap. I used a drift to take out the locking pin from the 'neck' of the alloy nose.

Drift The Locking Pin From The Nose Cone

The body and solenoid were then separated from the nose cone, by sliding off the long insulated bolts.

Splitting the Starter Motor

Solenoid Plunger and lever Fork: Detail

I hadn't managed to work out what size bushes were fitted to the nose cone - it wasn't clear from the parts books. Mine looked fine anyway and, as the motor only spins briefly, I reasoned it did not get a lot of wear and tear, so left well alone. The insulated bolts were removed and the nose cone was then vapour blasted, taking care to avoid the bush.

The next task was remove the armature from the starter body: To remove the starter pinion from the armature I used a long reach socket to release (push down) the locking collar, which then gave access to the circlip within. This proved quite tricky to remove.

Push The Collar Down To Reveal The Circlip

Once the circle is off, the starter pinion assembly and plate underneath were removed. The pinion teeth were checked for excessive wear and chips.

At the rear end of the starter, I winkled out the spiral spring clips from the motor brushes, allowing the armature to be released.

Using soft jaws I carefully clamped the armature in a vice to remove the bearing plate.
Removing the end bolt (IT IS REVERSE THREAD) and locking washer from the plate revealed a number of thin washers and insulators. I made a note of the order of removal and carefully removed the bearing plate.

Bearing Plate and Washers. Bolt is Reverse Thread

Under that was another series of washers and insulators. Again I made a careful note of the order in which I took them off.

Washers on the Armature

The solenoid was carefully dismantled. The large bolt that passes through the pivot on the lever connects to the solenoid plunger and is adjustable to give the correct 'throw'. Hence the removable rubber or metal end cap. I made a note of how many turns it took to separate the bolt from the solenoid. Be careful when removing the operating lever as it is made of plastic.

Solenoid Lever Fork Dismantled from Plunger

There is a also a shaped metal collar that looks like the boss from a Yale door lock. This has a similarly shaped paper gasket attached to it. This is a sealing plate that keeps dirt and dust away from the arm and pinion. Try to retain, or be prepared to replace the paper gasket with something similar.

All the parts were de-greased and cleaned of rust. 

I couldn't remove the inductor windings from the body. I couldn't budge any of large screws holding them in, so left well alone. With the windings still inside, I carefully cleaned the body using a wire wheel and then applied phosphoric acid to kill any remain rust.

Cleaning the Body

I did the same with the solenoid. 

Solenoid Ready For A Clean Up

I gave the body an initial couple of coats of paint before further re-assembly. And did the same to the solenoid.

I'd already bought a replacement brush set from Der Franzose. Four brushes for the 6201A: two are soldered into the body of the starter........

New Brushes on the Inductor Coils

.....and two are soldered on to the bearing end plate. It turned out that my old brushes were not badly worn, but some of the insulation was missing and damaged. So I removed and replaced them anyway - having first added some extra heat shrink. 

New Brushes on the Bearing End Plate

The armature shaft was gently polished to remove any rough spots and the commutator were carefully cleaned. I used a cocktail stick to clean out the grooves.

Commutator Was Polished with Emery and the Grooves Cleared

The nose end of the armature shaft was greased and the pinion replaced. The collar and circles were fiddly to refit: the collar compresses the ring and holds it in its groove. It took a couple of sharp taps with a hammer to get the collar to lock back over the clip without simply pushing the clip out of it's groove.

On the other end of the armature - and being careful to replace the washers and insulators in the right order - the bush of the bearing plate was greased before it was fitted on to the armature shaft. The brushes were located in place with their spring clips. The bearing plate and armature assembly were then inserted into the outer case. The remaining two brushes were fiddly to refit because of the limited space. 

The solenoid was reassembled and the pivot on the plastic lever was greased. With the armature now through the starter body, the starter pinion was liberally greased and the plastic operating lever fork engaged it it's slot. The bush in the nose was greased and the nose was then slid onto the solenoid and main body. 

The Solenoid and Body Were Mated to the Nose Cone

When I was happy that the dust shield and its gasket were correctly located, the holes through the nose cone and operating lever were aligned. Without using excessive force, the locking pin was then pushed through and home with a gentle tap.  The solenoid screws were tightened. 

The nuts on the long bolts were initially tightened down straight on to the bearing end plate - just to pull all the main parts together. I then removed the nuts, put back the domed bearing cap over over the rear end and loosely fitted the nuts again.

Following the recommendation in the HD 19 reassembly pictures, I briefly powered the starter using a car battery and, while it was running tightened the bolts. This is meant to ensure that the armature is 'true' to the bushes and can spin freely, but I felt uncomfortable putting a high current through the starter for anything more than a few seconds - the time it operates when you start your car. Hey, ho - it's done now.

Reassembled

Nuts, half-nuts and washers on terminals were replaced.

Clean Terminals

The terminals were then masked off - as was the tip of the nose, before I gave the whole thing a final few coats of paint. Half-spraying the nose cone and spraying over wires and grommets may sound odd, but that's what it seems to have been like when new.

Repainted

FOOTNOTE: Some years on from this, some asked in 'comments' how I adjusted the screw on the solenoid so I'm editing this post to include this note. Four years on, I can't remember how many turns it took to dismantle they nylon fork from the solenoid, and don't know how many when I put the solenoid back together. The adjustment is about turning the screw enough so that the pinion only goes forward so far when it's thrown forward. the adjuster fork on the solenoid fork controls that. The instructions for this are in Operation D.530-0 in the back of the 'Electricity' section of manual 814, but rely on the solenoid being off the car (so that you can measure the pinion position. Good luck!