Citroen BX (1983 - 1993) - 90 XU9 Pressure release screw pressure regulator

Honest John Back Room » Technical matters
What is life like with your car? Let us know and win £500 in John Lewis vouchers | No thanks
View Threaded
Sat 5 Apr 2008 00:22
90 XU9 Pressure release screw pressure regulator - igglypiggly
I have a MK2 BX hatch automatic 1990 XU9 engine, I need to locate the Pressure Release Screw to change the filter in the LHM res also to change the front brakes: The friendly specialist says it's supposed to be a 12mm nut style thing at the front of the Regulator and it's not!!

Is this bolt/nut style thing at the top or the bottom

Cheers

Edited by Pugugly on 05/04/2008 at 01:09

Reply | Report as offensive | Link
Sat 5 Apr 2008 05:21
90 XU9 Pressure release screw pressure regulator - AndyT
That's a blast from the past. I can't really help, but found some (useful?) info from google search regarding the BX, in the following links;

tinyurl.com/3kpw3d PDF parts manual. I guess item 12 on page 166 may be what you're looking for;

tinyurl.com/44y4xj has a diy section;

tinyurl.com/5xaldf


Edited by AndyT on 05/04/2008 at 05:23

Reply | Report as offensive | Link
Sat 5 Apr 2008 11:34
90 XU9 Pressure release screw pressure regulator - mjm
You don't really need to release the pressure to work on either the the LHM reservoir or the brakes. I had a 1991 16 valve petrol and the screw was on the front of the pressure distribution block, the one with the accumulator sphere attached to it. To be honest, I haven't seen one anywhere but there.

The filters in the LHM reservoir are plastic meshes, they are designed to be cleaned and re-used.(wash out in the sink when the coast is clear!) I think there are 3 in the block.

If you are going that far then set the suspension on low and change the fluid as well.
I found it easier to remove the whole reservoir(with the filter block removed) to drain it and clean it out.

What are you doing to the brakes?

Post back if you need more info.

HTH
Reply | Report as offensive | Link
Mon 7 Apr 2008 20:20
90 XU9 Pressure release screw pressure regulator - igglypiggly
Found the release screw by process of ilimination: had a hiss when I rose and lowered the suspension also an interesting tapping noise found the screw had loosened so all tightened haven't had a chance to check the filters.

I'm uprating the already good brakes to either Brembo combi or Black Diamond combi (slotted and drilled) I'm also going to fit twin carbs and a slight uprated cam 11.75 lift so nothing insane.

Reply | Report as offensive | Link
Mon 7 Apr 2008 20:38
90 XU9 Pressure release screw pressure regulator - Screwloose

Before you spend too much money; check the condition of the hydraulic pipes to the rear - particularly in the mud-filled corners.

The dreaded "puddle of green goo" has killed more BXs than anything else.
Reply | Report as offensive | Link
Mon 7 Apr 2008 22:13
90 XU9 Pressure release screw pressure regulator - igglypiggly
These have been checked no puddles of green goo anywhere. Going to replace the suspension parts anyhow as I do extreme mileage (40k+ and before anyone says buy new car these cannot do the mileage had three on 10 years all died at 50k)
Reply | Report as offensive | Link

Looking for a garage you can trust? Honest John's Good Garage Guide has thousands of reader recommended garages, plus how-to guides and tips on servicing.

The Good Garage Guide

Cold-snap snow-how: Advice on coping with the freezing weather, including videos, facts and winter driving advice.

Honest John's Guide To Winter Tyres