Citroen DS Hydraulic Pump

The Citroen DS hydraulic pump is integral to many key systems on the car.   Suspension, brakes, steering, gearchange to name a few.   All of these system rely on hydraulic pressure to do their job.   Other than early ID models, the DS uses a seven plunger pump and then a pressure regulator to ensure the right hydraulic pressures are maintained.

The pump on my car had been leaking more and more over the last year or so.   This is not ideal not just from a mess point of view, but can cause a safety issue.  The DS has inboard front brakes, and the leaking pump allows hydraulic fluid to drip onto the right hand brake disc.   Obviously this is not ideal for stopping power.

The DS hydraulic pump runs as an accessory off the camshaft pully.   On most DS is is a fairly straightforward exercise to remove it.   On a BVH car (semi automatic gearbox), the Centrifugal regulator runs as a subsidiary accessory and makes the job a bit harder.   The photo below shows the new pump tucked in under the regulator.

My pump was sent away to be rebuilt.  It came back looking much nicer than it left, with a new coat of green paint.

I had a friend help me change it out, who had done it many times before on his car.    We ended up having to do the job twice as we could not get the pump to prime the first time.   Normally leaving the bleed screw open, and pouring LHM down the hose will do the trick.  For some reason it wasn’t working for us.    Second time lucky, and the pump was able to build pressure, and without leaving a green puddle on the floor.

Before the pump was removed for rebuilt, I had started noticing a strange rattle from the engine.   At first I was a bit concerned about internal damage, but I realized that it wasn’t changing in line with revs.   Since the pump needed a rebuilt anyway, I figured it made sense to wait to see if the leaking pump was causing the rattle.    It wasn’t.

In the end, while testing the new pump we were able to find the cause of the rattle – the air cleaner.    Our assumption at the time was that the air cleaner was loose.   Today I removed it to check the various mounting screws.    I found that it wasn’t loose, the mounting bracket was broken.  The broken bracket was allowing vibrations to cause the air cleaner to rattle against the remaining bracket.

I’ll have to find a new bracket.  I’m sure used ones are available.   I guess it could be fixed but a used one seems a much easier option.