Dressing The Engine (Part 4) - Hydraulic Pipes on Ancillaries

With the main ancillaries on, I was able to add some of the hydraulic pipes that connect between these, and to the wider hydraulic system. Some of the lengths are 'simple' pipes with a male flare nut fixing at each end. If need be, these pipes can easily be replicated using a pipe flaring tool fitted with the appropriate Citroen flare dies. 

Pipework.......

Other pipes are more complex and have a flange plate at the end. These pipes are harder to fix or replicate. It's not impossible - just difficult to get a suitable seal between the pipe ends and the opening on the flare. Luckily some of the more common flange-plated pipes are now being reproduced and are available from the usual DS parts suppliers - but be careful as there are some differences in the routing and arrangements of pipes over the various years and models and so replacements may not fit!

Partly because of these differences, I was keen to press as many of my original pipes back into action as I could.

Collective nouns: A 'vipers nest' of hydraulic pipes?

After the vapour blasting I rinsed all the pipes in the bath to flush them through, and blasted them through with compressed air. Finally I gave them a rub over with an oily rag - just to provide a protective coating. Where they were badly bent, I re-shaped them as best I could - but that meant a lot of trial and error fitting for each one. 

I had cleaned and zinc coated all the clips that hold the pipes in place and had bought new rubbers to go in these.

Pipe Clips and Rubbers

Different cars have different pipework - certainly depending on whether they are bvh or mechanical gear change. I've seen photos of early (red fluid) DS21s with no bleed nipple on the centrifugal regulator for example. The exact routing also varies between years.

Anyway, here is how mine is plumbed. Lots of test fits were required and, when I thought I had the shape just right, I added on the clips and rubber collars as necessary.

First up was the flange and pipes from the side of the CRC.

Flange sealing plate and 'O' rings on the CRC

One of the pipes goes around the front of the distributor tower......

Clutch Cylinder Pipe Passing Under The Distributor Tower Bolt

......to the clutch cylinder - tucked away under the water pump housing.

Clutch Cylinder PIpe

The other pipe from the flange ducks down beside the fuel pump and will eventually join to a pipe on the chassis leading to the 'gear brain'. 

Red Capped Pipe Is From The CRC

Next up was the flange and pipes from the top of the centrifugal regulator. 

Centrifugal Regulator Pipework

I'd managed to find a 'new old stock' (NOS) pipe as the one from my car looked pitted and corroded in a couple of spots. One of the pipes from the flange crosses the engine behind the water pump.......

Pipe Passes Behind the Water Pump Housing

.....where it passes the distributor and CRC........

Long Flange Bolt On The CRC

.........and then does a quick loop-the-loop to (eventually) join the mounted union above the 'gear brain'. The 'loop-the-loop- in the pipe is to reduce stress and the likelihood of cracking.

The other pipe from the flange goes forward over the top of the regulator.......

.......and then down alongside the bracing bar between the centrifugal regulator and the HP pump.

There it is joined to a second length of pipe.....

Pipe Join Alongside HP Pump Bracing Bar

....that goes to the clutch lock mounted on the front side of the gearbox.

Hydraulic pipe to the clutch lock

Next up was the long pipe from the side of the centrifugal regulator.  

This bolts on to the back end of the bolt holding the HP pump bracing bar. (On some cars this is bolted to the front - where the bracing bar is).

Pipe routing on my car

The pipe goes down towards the gearbox and will duck under the steering rack and join the O/S front brake caliper (which is why that brake is bled from the nipple on the centrifugal regulator).

Last up was the long pipe from the accelerated idling device on the carb, down to the N/S brake caliber (again - being the reason the N/S brake is bled via the accelerated idling device). 

I spent a LOT of time trying to get the shape of this right. Shape is important as the pipe ends need to enter the receiving holes dead straight - otherwise you risk cross threading the flare nut (or it won't do up at all). Anyway, after much bending and twisting, I succeeded in....... weakening it and breaking it in half!

 Luckily it is a 'simple' pipe without any flanges - it just has a flare nut at each end. I'd bought a pipe flaring rig from Plaiedes back in 2015 and finally was getting to use it. The (replacement) pipe, with protective sleeve, runs under the CRC......

........down by the fuel pump..........

.......where it crosses behind the HP pump pipe (I was careful to make sure these two could not rub against each other) before running forward to the N/S brake caliper,

Next up will have to be a rebuild of the front brakes and I will be able to connect these stray brake pipes.