Peugeot 504 brake

[Datsun fan]

Every 1 month I have to bleed the four wheels and I find air in all of them,no fluid leak.

I replaced all drum and booster reservoir rubber seals but the problem persists :blink: .

Anybody know what to do ????

[sssr20det510]

are you loosing any fluid ??

[72240z]

If there is air doesn't there HAVE to be a leak? :blink:

There is only so much space.....

[Datsun fan]

No, I don't loose fluid ( monthly check)

[yello620]

This air problem can happen if your residual pressure valve(s) are going bad. When this valve goes bad, fluid pressure is released to fast in the wheel cylinders and then actually sucks in air. The valves are also designed to maintain a small amount of line pressure so that the wheel cylinder seals always have pressure on them.

 

I have no idea where peugot put these pressure valves, or if they bothered to install any. Most commonly they are in the master cylinder, but they can be installed inline also.

 

The inline valves are a common part to install on custom street rods, especially when the master cylinder is under the floor and might be lower than the wheel cylinders.

[Datsun fan]

How to check the valvs ???

Regarding bad M/C , rebuild or throw away and get new one ??

 

Thanks fellas , you really rock! ;)

[yello620]

How to check the valvs ???

Regarding bad M/C , rebuild or throw away and get new one ??

 

Thanks fellas , you really rock! ;)

 

Checking would require line pressure guages.

 

I have never seen a rebuilt master cylinder last longer than about 12 months, so i always suggest new if it is available.

 

Good luck

[Datsun fan]

I'll try NEW M/C soon and get back to you ASAP!

thnx