I start driving with about 6 or 7cm of free play. Keeps getting less & less. Within half hour, there is no play at all and brake lights are on all the time by then. None of the wheels will be really hot at this stage, just warm and nothing is dragging!! What's going on?
Raf

[Edited on 14-9-2003 by karmannghia60]

Raf

Have you replaced the rubber flex hoses in the past 20 years.

they deteriate from the inside and only allow pressure one way therefore locking yr brakes on all the time.

replace the 4 of them and bleed the system.

Or what else have you done to the brake system recently ???l

No I haven't but I did a lot of stuff about 5 months ago including reconditioning the master cylinder and replacing two wheel cylinders. The main seal on the master "felt" big when I was putting it in. Till now, first time I hit the pedal after the car has been sitting for a few hours, it feels like its being freed from a stuck position (if you know what I mean) but that's it. Wouldn't feel like that at all when driving. How would I tell if the hoses are hosed? If I bleed every wheel and there is good oil flow, does this tell me hoses are OK?

I reckon Dave sounds on the money. Restricted hoses tend to act like a one way valve, the high pressure from your foot will force the fluid through the restricted hose. By the lift pressure of the shoe return springs aren't enough to put it back the other way quick enough.

Could also be blocked residual pressure valves, but if the master cylinder was reconditioned then that should have taken care of them.

You carnt really tell if the hoses are hosed or stuffed for that matter

They are stuffed on the inside, do they look like the origional ones with the raised pimples on the outside.

I take it its a single circuit master cylinder system

ring me if you have time or U2U me yr number

This can also happen because the little "flapper valve" on the master cyl piston doesn't let the fluid "escape" when you let the brakes off. It can also happen if the m/c pushrod is too long & doesnt allow the piston to come back far enough to let the fluid escape thru its port. I know you have slack when you start- this may be due to air or brake adj issues- and after a few jabs the cylinder pressurises & can't "let go". Overnight, it eventually de-pressurises till the next time! It can be a real pain to track down- good luck!!

Yes Raf

Have you got the pedal free play adjusted correctly... and if its a single cylinder do you have the elongated washer under the rubber on the fluid inlet line.

I think free play is adjusted properly. What I will do on the weekend is bleed the whole thing again, readjust shoes all around and check free play.
Dave, yes its a single circuit. I am not sure which washer you are refering to? Is there a washer supposed to be under the inlet line in the M/C? I can't recall that I came across one to tell you the truth. Don't fancy checking it because I will get air in the system

[Edited on 11-9-2003 by karmannghia60]

If its not the hoses , I would be checking for corroded slave (wheel) cylinders) Have had this with the Oval over the past couple of months. One was so bad that the wheel was really dragging badly. So hot that you couldnt even touch the hub cap. New wheel cylinder and problem all gone.

Raf

Yes its under the inlet line rubber onto on the master cylinder... Its a small washer looking thing with an elongated hole slot in the center,,,, has something to do with the fluid returning to reservior..

If you find the hoses with the pimples on them front and rear then these are origional and say your car is over 40 years old then i would say there FUCKED.

So before you adjust shoes and bleed systems please replace these with genuine german ones. there about $40.00 bucks each

Dean could be right as well about the frozen wheel cyclinder, Ive also had this as well as the wrong shape brake linings on the front. They have to match the groove in the wheel cylinder piston. Either curved or straight on the brake shoe contact area.

Raf just had another read (properly) of your first post. If the brake lights are on then the problem is in the Master Cylinder. If it was the hoses and wheel cylinders then the brakes lights would not stay on. The switch is on the Master Cylinder. Obviously there is a pressure venting problem in the M/C somewhere.

Sh!t, that means I have to pull the damn thing off again and replace the rubbers AGAIN.
But what got me stumped is why is this happening after driving for a while? When I start off, everything is OK. Free play is fine, brake light is NOT on. Drive for 1/2hr and you can feel the pedal getting higher and the brake lights stay on all the time then. Again, wheels are NOT hot, just warm which tells me nothing is dragging (yet).

Raf

Bring yr car to Sunny Sidney n i will fix for yar.

I wish, can't drive it for more than 1/2hr remember

What happens is it builds up gradually each time you use it.

If you let it sit is weeps past and is right to go.

I had this problem a few times when I started putting Golf M/C on Buggies. I didn't set up the pedal throw properly. What happened was that it wouldn't let the plunger all the way back out so it slowly built up pressure until it was rock hard.

Pretty sure it is your M/C.

Thanks all, I adjusted the pushrod on the weekend and drove it to work this morning. Pedal is not raising and no brake lights on all the time after driving for a while. SHe's sweat now.
Thanks again
Raf

My brake lights were staying on all the time after driving for about 1/2hr because pressure is building in the system

So do the brakes feel right now... and do they stop OK.

[Edited on 15-9-2003 by vw54]

Yep, everything OK except I discovered something else which I will ask in a different thread
Raf