Brakes Urgent

[Tallen10011@aol.com]

Hi Everybody,

I have just encounted a problem.
The brake system on my 94 3.0 L diesel seems to be pressurising. The brakes are coming on slightly whilst driving causing the brakes to overheat. It only appears to affect the front brakes. I then turn off the engine and leave for a short period and it seems to clear itself. The problem can occur at any time whether the engine is hot or cold.

Is it a problem with the servo . Pressure switch ( the round box with the wires and pipe before the servo).

Help Please anybody!!!!!!!!!!!!!!!!!!!!!!!

[rich]

Hi,

This sounds more like the pistons in the brake calipers are sticking on. You will need to take them off and make sure that they are free.

Unlikely to be the servo as if this breaks you will get a pressurised brake pedal and reduced braking.

Hope this helps.

Rich.

[Tallen10011@aol.com]

Sorry Rich I don`t think that this is the answer. When the problem occurs both front brakes come on. When I looked into the problem it appears that a certain amount of brake fluid has been forced out the top of the reservoir.

Any more ideas?????????????

[TonyN]

I'd check the master cylinder first, one of the valves could be sticking, something in the servo could be jamming as well.

Dunno about the overflowing fluid, this normally happens if you top it up with worn pads, then when you fit new pads the level will be to high.

Are you sure the pistons arn't sticking in the calipers?

[rich]

Sorry, cant think of anything else.

Sorry Rich I don`t think that this is the answer. When the problem occurs both front brakes come on. When I looked into the problem it appears that a certain amount of brake fluid has been forced out the top of the reservoir.

Any more ideas?????????????

[big d]

tallen, how old is your brake fluid? its possible for fluid to absorb moisture and then a little warmth from the brake has the effect of expanding the fluid in the pipes, and therefore literally applying the brakes for you, i am going back a long time with this one, and to be honest with you have never encountered it personally, but i do remember reading the article,

[FlySurfer - Edy.]

yip sounds like the brakes are overheating the fluid which is then expanding and pouring out. had it on a bike once.

prevention is better than cure.

[snowwolf]

sticky brakes

I have owned quite a few oldish cars and the problem you discribe sounds like the pistons sticking, remove the wheel and the pads, get someone to push the brake pedal untill the piston comes far enough out, but not to far as for it to come right out, peel back the dust seal and clean up the piston, then give it a nice smear of rubber grease, relocate the dust seal, push piston back in with a g-clamp and a packer if need be, when all the way back in, (keeping an eye on the resevoir making sure it does not overflow) put it all back together, pump the brakes and do the same with the other brake.

I think that will cure your problem.

[Phil H]

I have owned quite a few oldish cars and the problem you discribe sounds like the pistons sticking, remove the wheel and the pads, get someone to push the brake pedal untill the piston comes far enough out, but not to far as for it to come right out, peel back the dust seal and clean up the piston, then give it a nice smear of rubber grease, relocate the dust seal, push piston back in with a g-clamp and a packer if need be, when all the way back in, (keeping an eye on the resevoir making sure it does not overflow) put it all back together, pump the brakes and do the same with the other brake.

I think that will cure your problem.

I aggree with all of the above. My van brake pads were shot last week and one of the symptoms(apart from the grinding noise!!) was that the calipers were not opening after braking and causing the whole area to heat up. If your pads are well worn the piston could be pushing out to a dirty edge which will cause it to stick on a bit. The piston is after all only a metal tube and if the dust cover has ever been disturbed then it will start to rot at the edges. Don't forget to take the cap off the fluid system before you try to push the piston back in (unless you have hands like a vice!)

Good luck

Phil