Cylinder Head Woes...

I'd bought an old DX engine particularly so that I could use the cylinder head on my DS in place of the DX2 head that was fitted.

By mid August 2017, and with the bottom of the engine rebuilt, I turned my attention to the DX cylinder head. The rocker assembly had been removed when the engine and cylinder head were separated. 

One of the long tubes that the spark plugs sits within was missing. on closer inspection it had rusted away at the level it joins the cylinder head. I would have to find a way to fix that......I started removing the spark plugs, the fourth one  - where the 'funnel' was missing - completely disintegrated. All it left leaving a knobbly, rusty stump. I would have to find a way to fix that too.....

Remnants of a Spark Plug.......

Using a valve spring compressor I set about removing the valves. The technique is to start with the valve compressor lever closed and the arm would back. Keeping the compressor closed, locate the ends on the valve and spring. Then wind in the arm until the spring is sufficiently compressed to enable you to reach the collars under the cap. To release the spring, use the lever arm on the compressor - don't wind back the arm. in this way, the degree of compression is 'set' so that to remove the next valve, you only need to operate the lever to compress the spring to the right degree. Well, that's the theory.....Initially I didn't find this easy as my choice of compressor had been the wrong one. A 'Laser' brand 0287 model. 

Although it had adjustable width jaws - useful for maximising the space needed to remove the cap and collars from the valve stem, it barely had the 'reach' around the cylinder head to clamp over the valve head. With some careful placement, it worked at first with, as ever, all the thrust washers, caps and collars associated with each valves going in to labelled pots. However after a couple of valves the adjustable end of the compressor buckled and gave way.

Looking for something else to do, I gave the cylinder head a shake a ton of grit and hard core fell out! I was amazed at how much there was!

I removed the remnants of an exhaust gasket and noticed - for the first time - some significant pitting around one of the (exhaust) ports. Worse was to come: on closer examination of the port I found that I could see the back of the valve seat exposed. The area around the seat was badly corroded. I'd had the engine the best part of a year. Why had I not noticed this before!

Exhaust Port Damage

Valve Seat Eroded and Exposed

I had a sleepless couple of nights. Even if the rotten spark plug stump could be removed, could this be repaired? If so, how and by who? Could I trust the repair to hold out? If I left it alone, and reassembled the engine, would I risk the valve seat collapsing into the cylinder - causing significant damage? This was the last straw. I decided I couldn't take the chance and would need to find another DX cylinder head.....

I rang around. Addie had a head but had already invested significant time and money in it: it was out of my price range. Jamie at DSWorld had a look but drew a blank. Darrin at Citroen Classics thought he had one and would have a look around. After an anxious wait for a call back, he came up trumps! AND it was very reasonably priced. 

On 1 September 2017 I made an early morning dash down and around the M25 to Citroen Classics in Staines. My first visit! I collected the head and a few other bits and pieces and was heading back home before 9am - getting back miraculously by just after 10am. I still don't know how I managed that. So now I had three heads..........

DX2 +2(DX) = ?

While this was going on, I went big and bought myself a Sykes-Pickavant 03950000 valve spring compressor. No messing. This is more of a closed 'C' shape design and, although it has fixed sized adaptors, made easy work of removing the remaining valves on  the  heads.

In mid September 2017 I found a local machine shop and got the DX cylinder head skimmed and vapour blasted. Boy did it look good. Stunning in fact!

Shiny..........

Then I noticed a problem...... There was a tiny, tiny, pin-prick hole eaten away through the water way to the outside of the block. The vapour blasting hadn't caused it, but had revealed it. Perhaps no bad thing. I was however gutted....

The hole was right on a corner at the water pump end, with the erosion perhaps caused by the flow of coolant through the head. I compared the DX head to the later DX2 head and found that the casting had been changed on the DX2 to include a large, prominent extra lump of casting at that corner. Perhaps it was a known weak spot?

Other DX Head: Eroded Valve Seat But No Pin Hole in Water Sleeve.....

DX2 Head: Extra Casting Lump in the Corner

I gave it to Barry - my machine shop guy  - to assess and he concluded that to repair it he would have to cut away quite a bit of the  corner of the block.  I trusted his opinion, but didn't fancy the sound of that, so looked for another solution. I used a two part, Loctite filler product used for pump repairs and similar. It's aluminium based and resistant to high temperatures. 

With the eroded area already having been cleaned by the vapour blasting, I degreased it all down with alcohol before filling the hole - making sure the Loctite oozed out of the pin-prick hole. Following the example of the DX2 head, I built up an additional level of filler to provide added protection. The repair looked good and was invisible from outside the cylinder head.

Now nearly mid October 2017, two months had gone by since I completed the bottom of the engine. Perhaps at last I had a decent cylinder head and could get on with the rebuild!

NOS Heater Hose

You are probably used to seeing Ds with the white plastic, cable operated heater valve on top of the heater matrix. Things weren't always that way.......

Prior to the 1969 model year (before September 1968), the heater control valve was operated by a rotating knob on the bulkhead below the dashboard. 

Pallas Heater Control - pre 1969

In fact the knob IS the valve: the valve part is in the engine compartment and buried way down at the back of the engine where the timing chain is.

The Heater Valve is on the Engine Bulkhead

The valves get silted up, or the knob goes stiff - or both. It is just about possible to service the heater valve with the engine in, but it's not much fun. (Don't ask me how I know). 

Because the valve is on the bulkhead, the metal pipe that runs from the cylinder head, along and over the exhaust manifold,  has a downwards curve at the end - so that the rubber pipe that connects to it dips down behind the timing chain cover to the valve - rather than running horizontally across and round to a valve on the heater matrix.

While my engine is out I'm planning to overhaul the valve and change the seals. I also needed to get one of the metal pipes with the curve at the end, as mine was silted up and the curved end had completely rusted off! I found one - but it was considerably more expensive than the straight ones found on late cars.

Heater Feed Pipe - 1965 to 1968

I also wanted to replace the rubber pipes that connect to either end of the heater valve - as they are hard to get to once the engine is back in the car.  The one on my car that runs between the valve and matrix in the 'snail' blower looks to be original as it has a grey outer shroud on it. It looks to be in okay condition. However the 'S' shaped one between the metal pipe from the cylinder head and the valve had seen better days and is perished. I bought a reproduction one at Citromobile in Holland in 2016. 

More recently I got lucky and found a NOS (new old stock) one. Same price as the repro one! I couldn't resist.

Reproduction parts sometimes get a bad press for their shape, colour fit or quality, Sometimes all three! Out of curiosity I've compared my heater pipes:

• Starting from the bottom we have the new old stock part. It has a distinctive 'S' bend shape to it and an outer protective grey sleeve.
• Above that is the reproduction part I bought in Holland. It's pretty close in shape to the original. The curves seem sharper, and it hasn't got quite the right profile, though it's sufficiently close to be bent to the right shape. The end are longer - but it's easier to make something shorter that it is to grow it by a few inches - so that's not a problem. It lacks the grey outer plastic covering.
• Above that is the 'S' shaped hose that came from my car. It's clear that it's just a piece of hose of approximately the right shape that someone has put on at some point.
• The metal pipe with the curved end is at the top. The only difference from the one fitted to later cars is that small kick on the left hand end - but they are nearly double the price of the straight-ended ones.

When I get to that particular job, I will fit the NOS heater pipe. Maybe I should keep a look out for a NOS pipe for the other side?

Engine Rebuild (Part 3) - Timing Chain and Sump

With the crankshaft fitted, I moved on to the camshaft and timing gear. The important thing here (for timing/ firing) was to align the marks on the two sprockets before final fitting of the chain. The marks are quite subtle. On the camshaft sprocket, the relevant mark was a single painted tooth (repainted in my photo below)......... . 

Repainted timing mark on tooth of cam sprocket

........and on the crankshaft sprocket the relevant mark was a small notch between two teeth:

I was too busy to take photos, but the principle of reassembly is that with number 1 and number 4 pistons at about top dead centre, and with the chain held taught on the chain guide side (not fully taught in photo below) a straight edge should pass through the centres of the sprockets and these two marks. Turning the camshaft and sprocket and/ or crankshaft allows you to move the chain by a tooth or two until you find the 'sweet spot'.

Marks on sprockets face each other and align

I'd had a new timing chain fitted by Doctor Chevron back in 2002 and it had probably done no more than two or three miles after the engine had been refitted all those years ago. The timing chain got re-used - as did the chain guide and tensioner. I followed the assembly and alignment procedure - reading the instructions in manuals 518 and 814 very carefully. The guide was fitted and adjusted with two feeler gauges (and three hands) and the chain tensioner was fitted and 'activated'.

With the camshaft and timing chain in place, the oil pump could be fitted. The pinion on this is driven by the camshaft. 

The Oil Pump is Driven by a Gear on the Camshaft

The oil pump was correctly orientated so that the hole in the stem aligned to the threaded hole in the engine block. The pump was then pinned in place with the screw and lock nut.

Pin and Lock Nut for the Oil Pump

With the other end of the oil pump bolted to the bearing cap, the sump was fitted. Having had to sort out a stripped thread on the sump plug hole, I thoroughly cleaned the sump of any swarf before fitting it. I smeared a very thin bead of RTV silicon on the mating surfaces. Not too much as I didn't want it oozing into the sump. There is also a cork gasket that fits over the curve of the flywheel end bearing cap. That was similarly held in place with some RTV.

It's important to get the location of the two long bolts correct as these will serve the secondary purpose of holding the triangular bracket that supports the down pipe/ flex-pipe join. Where did I put that bracket.....

Long Sump Bolts for Exhaust Bracket

After the sump, the timing chain cover was fitted.

Bottom End Done - 13 August 2017

Sump Repair and Fitting

While I was cleaning my sump up in July - the sump plug fell out! The thread on the sump was almost completely stripped and the plug was a loose fit.

I have a second sump - from the engine pulled from the car. I wasn't keen to use that as it had lots of stress and fatigue marks on it and I didn't want to use it in case it cracked and leaked. Anyway, my 'loose' sump plug was too tight a fit on that sump - which explains why it stripped the threads on the other sump when it was fitted. It wasn't the right plug for a DS sump.

At least, with two sumps, I had a second, proper, DS sump plug. I could use the other plug, but first I would need to repair the threads on the sump. But how best to proceed.....Sharing my woes on the CCC website forum there seemed to be two options - a heli-coil or a Time Sert. No - I didn't know what one of those was either!

The simplest way to describe a Time Sert is that the principle is like a helicoil - essentially a replacement thread -  except that a 'Time Sert' insert (bush) is a tubular threaded sleeve (threaded on both the inner and outer faces). It is threaded into a over-sized re-tapped hole and pressed into place - (re)creating a tapped hole of the original and desired size.Then I got an offer I couldn't refuse: a kind soul (who wishes to remain anonymous) offered to lend me an appropriate 'Time Sert' kit suitable for a DS sump plug.

The kit arrived in the post a few days later. Excellent service! After familiarising myself with the equipment and process I gave it a go.

Clamping the sump to my work bench to stop it moving about, the process was very straightforward - other than that it had to be done by hand.

• The errant hole was drilled out (no going back now!)
• A seat cutter was used to cut a recessed seat

Preparing For The Time Sert - 12 August 2017

• Next the hole was tapped over-sized
• Fitting the 'Time Sert' bush on to the lubricated insertion tool, the bush was screwed into the hole until it was sitting flush on the recessed seat.
• The Time Sert insert (bush) has part-formed threads on it's inner face. Continuing to rotate the insertion tool did two things: it finished creating the thread in the bush and, as it did so, it expanded the Time Sert bush so that it fitted the tapped hole tightly.
• The insertion tool was then withdrawn - leaving the bush in place.

I used a file to dress the sump/ bush surface to make sure the insert was flush to the sump face - so that I could be confident I could obtain an oil-tight seal when fitting the sump plug. 

Done!

Engine Rebuild (Part 2) - Pistons

With the crank in place I moved on to re-fitting the pistons in the liners. If you follow the procedure for reassembling the engine as covered in Operation 100-3, the pistons are inserted in the liners before the liners are put back in the block.

I actually followed the process shown in a DSSMPassion video and fitted the pistons after the liners and crank:

DSSMPassion: Replacing The Pistons

My liners were clamped in place to stop them moving around, and I'd shaped large flat washers to allow me to slide the pistons past them.

Bolts and washers for Retaining the Liners

All the parts had been ultrasonically cleaned and lubricated and were neatly laid-out. Ring and re-reading the workshop manual I made sure that the con rods were attached to the pistons the right way round relative to the crowns of the pistons. 

The ring set was confusing as, although it was obvious which were the scraper rings, the others looked very similar and I wasn't sure which way up to fit them. it took me ages to find the word 'top' clearly marked on them........

Pistons Ready For Re-fitting - 4 August 2017

I'd bought a cheap pair of piston ring spreaders to help me fit the rings to the piston and they worked very well. The trick was to open the ring just enough to slipover the lands - but not to open them so much that the rings snapped..... All went well. On each piston the rings were orientated so that the gaps were 120 degrees apart and not aligned. I believe this helps to optimise compression. 

With a generous squirt of oil, the bearing shells were fitted to then rods. I'd also bought a cheap piston ring compressor - one of those coiled spring things, operated by a key. Again, things went remarkably smoothly. Making sure the piston crowns were correctly orientated, with the aid of the compressor, pistons and rings were eased down into the liners. With a bit of fiddling I aligned them to the crank by refitting the flywheel bolts in the end of the crankshaft and using a breaker bar between them to rotate the crank a little. I added the other half shells and con rod caps - being careful to match them to the appropriate con rod -  and torqued them up. 

Engine Rebuild (Part 1) - Liners and Crankshaft

I mounted the engine back on the stand. This time I had added some extra bracing bars to the arms of the stand - made from very sturdy angle.  These allowed me more flexibility as to the mounting point I could choose on the engine - thus distributing the load better and putting less strain on particular parts of the block. It had been quite fiddly deciding quite how to cut these and where to put the holes. I also had to factor-in the need to be able to put the sump back on. Trial and error proved the way forward.

With the block painted and on the stand, the serious work of rebuilding the engine could begin. Lots of research....

The procedure for reassembling the engine is covered in Operation 100-3, which you can find in Section 2 of Volume 2 of manual 814.

I also used a very handy set of three videos from DSSMPassion. You can find the first part here:

Engine Rebuild Video - First Part

I'd drawn a blank on trying to find the correct spec. head gasket and liner seals for my DX engine (see other post....) and had decided to go with the contents of the 'standard' gasket set I'd bought from Citroen Classics a year earlier.

The first thing fitted was the liners. That meant fitting the delicate paper seals around their waists. I'd been dreading this...... Not only are these seals very thin and delicate, but they are also a notoriously tight fit around the liners. If they tear and the liner is not properly sealed, coolant will leak into the sump. I won't know if I've done this right until I give the engine a proper test with radiator and coolant fitted.

Several different sets of these paper seals are provided in the Glaser brand engine gasket sets that are available. Taking advice, I used the straight edged set for my 21 engine - not the set with wrinkly edges. Knowing how delicate they were, and not being sure if the seals in the set would be thick enough to give the right liner height, I also bought a spare set of seals from the Citroen Classics stand at the D rally earlier in 2017 - just in case.

Well, the seals that came in the gasket set were tight. VERY tight...... I tried the set from Citroen Classics. They were marginally better. Boy these things were tight!

Fitting The Liner Seals - 3 August 2017

With the inner diameter stretching to fit over the liner, the shape distorted and they wouldn't lie flat. Once they were close to being in the correct location, I had to carefully tease them flat again. Even then, they end -up with a curled inner edge.

May Look It, But These Aren't The Wavy Edged Seals

I did a test fit of the liners: according to step 12 in the version of Operation 100-3 in Manual 518, the liner top should between 0.12mm and 0.16mm higher than the deck. Mine came up a little less than the minimum. When it came to committing for the fit, I believe the seals are meant to be fitted dry, but I put a tiny amount of Hylomar Blue on the bottom face of each seal. The liners were carefully lowered into place and the clearance over the deck check again. Still a little shy of 0.12mm, but very close. My main worry was whether, unseen, any of the seals had torn as they were being compressed. 

Once the liners are in place, they should not be moved or rotated - for fear of tearing the paper gaskets. The tactic is to hold them in place with a couple of bolts and washers in appropriate cylinder head bolt holes. Planning ahead, I knew I would need to insert  the pistons - so I shaped the washers to allow the pistons to be slid past when the time came.

Liners Fitted - 3 August 2017

With liners fitted and clamped at several points I turned the engine over and set to work re-fitting the crank. Bearing shells were lubricated and laid in the journals before the crank was lowered in. Lots more oil.

With the two intermediate caps fitted (caps 1 and 3, the end float on the crank was tested using a dial gauge on a magnetic stand. The DSSM Passion video was very handy for showing how to go about this. The end float is adjusted by using thrust washers of different thicknesses - standard or over-sized. As I only had the one set, I was mightily relieved when the end float came up within tolerance!

Crankshaft End Float Checked - 4 August 2017

With the end float checked, the remainder of the bearing caps and thrust washers were added and the caps torqued up.

All Bearing Caps Fitted - 4 August 2017

A Quick Word About...........DX Cylinder Wet Liners and Their Paper Seals

Well -  never did get to the bottom of this one......

I can't remember quite when it was, but soon after I'd decided to get my car back on the road, I was doing some research. Given the crossover from DX to DX2 engines, any mention of 1968 was going to catch my attention and in manual 814 and I stumbled across something:

So with the introduction of the DX2 engine in September 1968, there was a change to the paper rings that sit on the bottom of the liners ('barrels') and a corresponding change to the head gasket? Whatever this change was and meant, it was significant enough to warrant mention in the workshop manual.

As I needed to buy a gasket set, I made a couple of enquiries with the usual sellers, but no one could offer me "joints with packing" or a head gasket with "circular seal". In fact they didn't know what I was on about!

Intrigued I searched through the earlier Manual 518 (published in 1966 and so before the gasket changes) for further information. It offered a tantalising clue in the form of a photo:

The photo showed a gasket on a liner. The gasket was printed with two parallel lines to enable the fitter to orientate it correctly as per the fitting instructions. So, before September 1968, the paper seals on the base of liners were padded (with brown paper?) - but they weren't just thicker, the padded parts were not around the whole circumference.

Questions, questions: Why on earth would Citroen do that?  Why did they need to be aligned with the piston shoulders? Why were they needed? Why weren't they needed after September 1968? Since these are joint parts, what was different about the parts they joined? Did those parts change after September 1968? What was all the business with the 'oval' and 'circular' head gaskets all about?

However 518 had something else to say:

So even before the change in gaskets and paper seals, there were two different sizes (heights) of liners - identified by a colour mark. Presumably you used whichever colour (height) was needed to give the right height above the deck? At this time, BOTH would have been used with the padded liner seals  and corresponding head gasket - as that was all that existed. The liners I puled from the car were so rusted that there was no hope of finding or identifying any paint marks. 

518 still had more to offer:

Top Photo in the Picture Shows Location of Engine 'classe' Stamp

So there are two different 'types' of liners and two different 'classes' (groups) of engines - and you need to use the right barrel with the right block? Now I was confused. How many variables were there! Were there two different heights of liners for 'classe 1' and two dfferent heights for 'classe 2'? There seemed to be lots of instructions telling you what you had to to do, but not necessarily how to do it! (Or why!!).

I searched for clues on my engine. The photo above from the manual is a bit hard to make out, but it shows an engine block marked as 'classes 1'. Here is the corresponding mark, under the oil banjo, on my block. Mine's a '2':

Engine 'classe' Stamp On My Block

I checked my liners.....

"Classe 2" DX Liner: Two Rings On The Upper Flange

After much searching I found two very faint rings ('00') - corresponding to liners that match with a 'classe 2" engine. So that was good then. Unfortunately, I was planning to use the post-1969 liners that Peter ('Badabec') had given me: so I had a look at those too:

D Super 5 liners - Marked '2' on the Upper Flange

They were marked with a '2'. Was that the later equivalent of the two rings on my earlier liners - meaning they were to be used with a 'classes 2' engine block? I couldn't be sure: other than mentioning the different gaskets prior to September 1968, manual 814 offered no special instructions/ requirements regarding liners matching to engine blocks.

I was way out of my depth now - just turning up questions and possible problems - not solutions. I'd found out too much! I knew things it wasn't healthy to know!

• Charles Vyse had also commented on the paint marks on liners in his recently published 'Goddess' book - finding an old address I tried to write to him to find out what he knew. No reply to date.

• Der Franzose sell two different gasket sets - in both cases these cover several engine variants.  Their part number 30008 is suitable for DX2 engines, but their part number 30009 is said to be suitable for DX engines - but that might just be a typo and, anyway, the set also covered post 1969 engines. With only one head gasket in the set, it can't have been that the difference was that the set included a head gasket with 'oval seals'.

• I found a thread on the "Club DS Deutschland" forum where a DS owner had struggled to get a gas and water tight seal on the head of his DX engine after a rebuild. Was this perhaps down to using the wrong gaskets? 

• At rallies I had checked the engines of some post 1968 cars and these continued to have a 'classe' number stamped under the oil pipe, so it MUST have continued to have had some kind of relevance to SOMETHING!!!!

This continuing uncertainty over gaskets and liners was now stopping me getting on with the rebuild......By the time of the DS rally in June 2017  - and with no clear answers on the horizon - I decided I'd had enough.

Since I couldn't satisfactory solve (understand?) the issues of the padded/ not padded gaskets, I decided to simply things by going back to first principles: when fitting the wet liners, the major consideration is for the liner to be proud of the deck by the correct height when fitted without, and then with the paper liner gaskets. The measurements are given in manual 518 and are in one of the photo's above. THAT'S what I would focus on.

As far back as June 2016 I'd bought a complete engine gasket set from Citroen Classics and at the 2017 DS rally I bought a second set of the paper seals for the base of the liners for ''extra padding' if needed. I would suck it and see.

Like I said I never DID get to the bottom of this one.......

Painting The Engine Block

At the beginning of July I picked my day and, early in the morning, took the block outside and gave it several good soaks and washes with Jizer - I used a paint brush to stipple the Jizer in everywhere. I hosed it down with a pressure washer and blew compressed air all over it - and especially through all the oil and coolant channels.

When it was all dry, and using a rag lightly soaked in engine oil, I wiped around the bushes of the camshaft (both ends and the one in the middle) and similarly pulled my oily rag through each tappet channel. Avoiding bushes I liberally applied Jenolite (Phosphoric acid) with a paintbrush - again stippling it in -  and then left it to dry. Dried Jenolite is removed by addding another wet layer, then wiping it all off with a rag. By the end of that day I had a clean, de-rusted engine block.

The next day I used panel wipe and a scrubbing brush to thoroughly degrease the engine. I masked-off the top of the block and other areas and sprayed the block up. I had searched long and hard to find a green paint colour that match that used on the engine block. It's different to the green used for LHM parts. it's more of an olive green? I thought I had found something fairly close in 'RAL 6020' ('Chrome Green')  and got a couple of cans of semi-gloss enamel made up.

The Personal Touch.....

When it actually came to applying it, I didn't feel it was the colour I was expecting. It wasn't quite dark enough. Whether this was because it was mixed wrong, or whether it was because it was being applied without an undercoat, I don't know. I had checked the colour at my paint mixers before I had it made up,  but I've just Googled it and, if you look at the variations in shade shown in 'images', it's perhaps not surprising that the colour I ended up with is not quite what I thought it would be - or expected. 

ANYWAY - it was done and was close enough. it was certainly much better than had been before and looked even better a couple of days later when I removed all the masking tape.

Repainted Engine Block - Ready for the Rebuild

I left the block to dry a good few weeks before I started work on it again. It would do no harm and I had other things to do.

Oil Pump - Strip Down and Overhaul

With the sump off, the oil pump was removed. As it is such a crucial part of the engine, it's worth giving it a service while you can get at it.

As well as reading the workshop manual (Manual 518, Operation DX. 220-3), I also watched these videos from "DSSMPassion Citroen" several times over:

strip down - https://www.youtube.com/watch?v=4Lz1XY3812Y

and reassembly: https://www.youtube.com/watch?v=UQ5AHbpn2js&t=142s.

The main aim was to make sure the whole thing operated smoothly and was not gummed up with burnt oil and sludge. I also planned to replace the two springs in the valves.

The Bypass Valve and Spring is on the 'Cup'.......

.......The Pressure Control Valve is on the Pump Part

The first job was to get the pump out of the engine block. Even with the locking screw (located on the tower) removed, pumps can still prove stubborn. With a little use of some Plus Gas and some gentle wiggling and rocking, the oil pump slowly began to yield and in this way was 'corkscrewed' out. 

Removing the bracket, the pump body was split into it's two parts. The 'Cup' part actually faces down in the engine and is the part that you fit your oil filter in to.

The Oil Pump Is Located In The Sump

Oil Pump Filter Housing - the Bit You See When You Change A Filter

 Splitting the pump gave access to the pumping parts. The engine cam shaft operates the drive pinion which turns the spindle. The inner, four pointed pump pinion rotates within the outer, loose pinion - which itself is free to rotate. This creates the pumping action. 

Ingenious Pumping Pinions

The loose pinion was easily removed. However removing the pump pinion that it fits around meant releasing the pump spindle from the tower. This is done by pulling the drive pinion off the other end of the spindle. However my three-legged puller was not up to the job and there was a lot of cursing as the puller's legs were too chunky to get any grip under the teeth of the pinion. In the end I asked Doug up at the barn to press the shaft through using his hydraulic press. If I had to do this again I would try and find a suitable ball joint splitter.

Pinion Was Pulled Off - 11 July 2017

With that drive pinion removed the spindle was pushed through the body, allowing the pump pinion to be pushed back along the shaft a little. The spindle was quite sticky and grubby at the drive pinion end and didn't want to come out too easily. 

Pushing the pump pinion back revealed the flat washer/ keeper and half-cotters that had been holding the pump pinion in place. Careful you don't lose those cotters!

Cotters and Keeper Removed

The pump was just about disassembled now.

Main Parts of the Oil Pump

With the body split and the spindle removed, everything was thoroughly cleaned in Jizer, rinsed-off, and dried with compressed air. As the pump was going to back in the sump, I didn't spend too much time on cleaning the body,  but all the moving parts were inspected and cleaned up and the spindle was given a gentle rub over with wet and dry to polish it. Using a small piece of safety glass (courtesy of a fridge at my local recycling centre) and some wet and dry squirted with Plus Gas, the flat sides of the pump pinions were re-surfaced, as were the two mating faces of the pump body halves.

The pinions and spindle were generously oiled for reassembly. The drive pinion on the spindle end was a very tight fit and took some heavy blows with a hammer to start to get it on. Luckily the pump end of the body provided a fairly flat and stable base, but you need to remember that the pump body is alloy and at risk of distortion. Any damage to the pump end of the body may mean that the loose pinion binds and does not rotate freely.

I found the DSSMPassion video confusing in terms of the float that the drive pinion should have (the 2min 20 second mark on the rebuild video refers). The figure given in step 9 of Operation DX. 220-3 of Manual 518 states the gap should be between 0.4mm and 0.5mm.

The oil filter body and main pump parts were then bolted back together. The pistons and bores were cleaned before new springs from Citroen Classics were fitted.

Replacing the Vavle Springs

Everything was given a last generous squirt of fresh engine oil.