172 cup Brake compensator valve

[ConnorCup]

Hi, i own a 172 cup with a standard braking system, the brake compensator valve is faulty i believe.
Are these specified to the 172 cup model or do other model valves fit?
As i need to buy one asap to get me to the end on the month.
Unless someone knows where to get a decent priced new item?
Thanks.

 

[peanuthead]

I may stand corrected but I'm sure this isn't used on the cup as it is preset at factory unlike the normal 172/182's

 

[Stu_350z]

What makes you say it it faulty? Did an MOT tester tell you this?

 

[peanuthead]

http://www.cliosport.net/forum/showthread.php?670611-rear-cup-brakes

Read the thread above will help you

 

[ConnorCup]

Ahh yea i just realised this, when i looked at it on the ramp i presumed it had the linkage and spring missing but it seems that they dont have them??
So anyone have any idea why my brakes do not work for sh1t then lol, seems the rears keep locking up?

 

[klem]

Defo shouldnt have a spring mechanism.

Is it just the rears that are under performing or is it poor braking in general?

 

[ConnorCup]

General, its more the fronts that are the worst i believe.

 

[klem]

Have you bled them recently?

Could be something as simple as air in the line. For how cheap and easy it is to do this its worth ruling out.

any other symptoms? low pedal?/spongy/grinding/pull to one side?

 

[itsjamz]

Yeah when I had my cup up on ramp I noticed it just looks like spring missing linking them together. So that's right?

 

[ConnorCup]

It would take about 2 mins to do it at the weekend on the ramp so its worth a punt i suppose. Reason i havent done it so far is that ive only owned it a week and the fact the brake pedal feels perfect and the fluid level is spot on. And when seeing the spring missing i presumed it was that!
Thanks for the advice btw

 

[Fred@BTM]

yeah its not supposed to have anything, the spring thing is £130 odd quid and not even required!

 

[ConnorCup]

Thanks Fred.
Ahh thats okay then, any other common problems that would cause really bad brakes, the discs and pads are decent and have plenty of life, the pedal feels awesome and fluid level is spot on? Try bleeding them and go from there, i put new rear pads on as a tempory fix due to the pads being quite low.

 

[klem]

I have a spare spring removed from my Cup... someone must've convinced a previous owner it needed one....

Id recommend bleeding and then re-assessing.

 

[ConnorCup]

Ok will do, i'll report back at the weekend
Cheers again.

 

[peanuthead]

I have a spare spring removed from my Cup... someone must've convinced a previous owner it needed one....

Id recommend bleeding and then re-assessing.

I had a spring as well till Fred spotted it and took it off

 

[Fred@BTM]

i must've removed a few thousands£££ worth of springs over the years! We have seen knackered rear valves (cira £300) but very rare, normally just strip and clean/bleed plus take the VOSA print out to the MOT test = pass

 

[Pauleds]

Ive got no braking to the osr wheel so when I do jump hard on the brakes the other 3 wheels are braking then the NSF wheel will lock up as extra pressure goes to that wheel.
That compensator thingy by the rear beam is off to the bin and the lines will be coming inside with a bios valve and maybe a hydraulic handbrake too.

 

[ConnorCup]

i must've removed a few thousands£££ worth of springs over the years! We have seen knackered rear valves (cira £300) but very rare, normally just strip and clean/bleed plus take the VOSA print out to the MOT test = pass

Thats wierd why they left the valve on there but have removed the spring? But cheers for the advice, cheers for the heads up in terms of MOT

 

[sam JFM]

Adding an extra spring to mine really helped,
it ment that the arm returned to its "up" position as the small spring had got to the point where it wouldn't

 

[ConnorCup]

Question is to spring, or not to spring lol.

 

[Fred@BTM]

it didn't leave the factory that way therefore no spring/arm!

 

[MG cup]

The spring force is over come by the force you press on the pedal and is only allowed to move as far as you have adjusted the allen key and lock nut. The spring returning it to the up position surely keeps the valve moving and helping to stop seizing no? You are more familiar with these cars though Fred???

 

[sam JFM]

it didn't leave the factory that way therefore no spring/arm!

I think this might depend on the viewpoint to which you look at adding a spring. In my case the spring was added to assist the small spring that is already present on the valve.

As i saw it when i replaced and bled my rear brakes the valve should be open at rest ( might be the wrong way round ) , when you press the brake pedal the valve will then start to close thus limiting the amount of pressure applyed to the rear brakes. On releasing the brake this valve should then re-open and reset the system.

The small spring that already exists applys the force to pull the valve open (Resting position), now over time this gets weak and no longer opens the valve. So when you come to reapply the brake the valve is closed and wont allow any pressure to the rear brakes resulting in NO (and i mean no) braking.


To test this theory i jacked the back of the car up - pushed the valve to the point where it is closest to the body (open i think) and span the rear wheels , i then put the brake on and the wheels stopped. I then took my foot off the brake, span the wheels and braked again (without touching the valve), this time the wheels carried on turning. so i then manually pushed the valve (Open) again - reapplyed the brakes and the wheels stopped leading me to belive that the spring was no longer returing the valve to its working position.

Added a spring (pics are on this forum) and the rear brakes now work time after time.

Just my theory ...