ZX brake pressure regulator valve problem

bv2991 · Post by **bv2991** » 07 Oct 2008, 15:08

Hi all,

I have brake fluid leaking from one of the Brake Pressure Regulator Valve on my ZX. They are under the car between the fuel tank and the spare wheel. One of them leaks fluid when the brake pedal is depressed.

I've taken the car to my mech, and he is sourcing the part. I'm just curious, can this valve be overhauled? How to do it, if it's possible?

Thanks in advance.

Sl4yer · Post by **Sl4yer** » 07 Oct 2008, 19:39

I doubt they can be overhauled - the look pretty sealed to me, and it's probably not worth messing with.

Both mine have gone in the past couple of years. It was a bit of a struggle to get hold of them here, so it may be even harder in Malaysia. If you can get them, and plan to get keep the car, it's probably worth buying 2. The other won't be that far behind.

James

oscarloco · Post by **oscarloco** » 08 Oct 2008, 22:54

Check the fittings and pipes first, it might be a simple case of loose connectors.

citronut · Post by **citronut** » 08 Oct 2008, 23:28

i always thought there is only one brake compensater valve on a ZX, it may be a dual valve unit, and normaly the pipe nuts are stuck solid and you end up replacing some pipes as well

regards malcolm

Sl4yer · Post by **Sl4yer** » 09 Oct 2008, 17:18

citronut wrote:i always thought there is only one brake compensater valve on a ZX, it may be a dual valve unit, and normaly the pipe nuts are stuck solid and you end up replacing some pipes as well

regards malcolm

Definitely two on models with rear discs.

Agreed about the pipes though!

James

citronut · Post by **citronut** » 09 Oct 2008, 19:24

if you are meaning the compensator valve on the rear axle, it dose not need two as it is only a load operated valve, which allows more fluid/presure to the rear brake circuit when you have weghit in the rear of the car, regardless of beeing a disc or drum brake car

regards malcolm

oscarloco · Post by **oscarloco** » 22 Oct 2008, 19:31

So, did you fix the problem?

bv2991 · Post by **bv2991** » 24 Oct 2008, 07:18

Not yet!

I'm still waiting for the part. The mechanic had placed order for it and was supposed to get it this week. If not, I've already located one in Kuala Lumpur (300 kms away!) brand new. Not cheap though at MYR 220.00 (for comparison, the front absorber costs MYR 240.00 per unit).

check here for some illustration:
http://cx.podolsk.ru/xm/docum/haynes_zx/zx-01.pdf

Definitely 2 units down there.

I'm checking and topping up the brake fluid for the time being.

citronut · Post by **citronut** » 24 Oct 2008, 08:29

may be you could post some photos of your twin compensators, as i have never seen such a beast, and cant understand why it would need two

regards malcolm

Post by **RichardW** » 24 Oct 2008, 09:21

Malcolm,

Item 1 is the ones in question. These are only fitted to ZXs hatches with rear disc brakes - they're pressure limiters rather than pressure regulators - Isuspect when they added the discs, they found they were too good and locked up so the pressure regulators were added. Usual failure is that they sieze up internally, then you get no rear service brake, but the handbrake still works. One of the (many!) failures on our ZX this year that sent it to the scrappers

No, I don't know why it needs one for either side - why not just one in the main feed line?

TBONE · Post by **TBONE** » 24 Oct 2008, 09:55

load proportioning valve is the right name and there is only one and works with the amount of weight in the car, you bottom right shows the valve and other is a pipe union nothing more and linked to valve so when it knows the car is loaded the fluid is pumped through other pipes to equalise the breaks to the rear

Post by **RichardW** » 24 Oct 2008, 10:14

Sorry TBONE, that's bollox

Item 1 is listed in the parts database as:

0000486150 PRESS REGULATOR 46.42 GBP 54.54 GBP

Expensive pipe union, no???

Also available from GSF:

T65383 BRAKE PRES REG ZX VOLCANE/16V(DISCS) 33.60

TBONE · Post by **TBONE** » 24 Oct 2008, 10:44

bolix indeed if you say so

compensator/proportioning valve is the same thing

bv2991 · Post by **bv2991** » 24 Oct 2008, 11:45

Okay, I don't quite know what it does, but my guess is it stops the rear brake from locking up. There's a built-in pinhole on its body. Right now, fluid oozes from this hole when pedal is depressed. Sorta saying that something seized-up inside.

Here's a close-up pic of it. Can you see the dot on the body? That's the pinhole.

Cheers

TBONE · Post by **TBONE** » 24 Oct 2008, 12:18

that's just a union and you can buy a new one ( I see the thread on the right hand side is well out ) compared to the left side this could be your problem as the leak could be coming from the thread rather than the union?, the reason they put a union there is mostly because its not possible to fit an all in one line due to things being in its way like going through the chassis

French Car Forum

ZX brake pressure regulator valve problem

ZX brake pressure regulator valve problem

still waiting for the part!

Here's a pic of it