Hi Everybody, I've been looking through the forum and it looks like there is lots of knowledge on here...I'm hoping to pick your brains and help me solve this problem which has been driving me nuts for about three months now!

The front drivers side brake seizes on after about 20 minutes of driving (it doesn't matter what kind of road or the distance travelled) and if you sit for 10 minutes with the engine off it seems to rectify it (and it doesn't happen for the rest of the day???).

My friend is a mechanic and he took a look at it - the master cylinder was leaking, so he replaced that....still happening.

He thought it might be the slider pin, so that was replaced too...still happening.

Next to be replaced was the caliper and brake pads...still happening.

After speaking to a few different people, he replaced the hose too, guess what? Still Happening!

As you can probably guess it is driving both me and him crazy, so I've turned to this forum as a last resort..any help or suggestions would be greatly appreciated.

If it's any help, the car is an 06 plate Fabia 1.0 with 27500 miles on the clock. New tyres all round, wheel alignment checked and nothing else apparently wrong with it. There is a slight bit of play in the front drivers wheel (CV joint - but friend says that it's only very minimal).

Thanks for looking and if there's anything else you need to know, please ask....

Given that just about everything that would cause this has been changed. Next culprit would be a sticking ABS modulator solenoid valve in the ABS unit.

I would have the brakes bled by a garage with the Skoda kit needed to modulate the ABS unit while bleeding the brakes. Not much change out of £1000 for a new pump, but they can be rebuilt by a specialist for £270

Thanks for the quick response Moggytech, just wish it was a cheaper solution. I got a reply on another forum about the same problem...

The way to approach this is to open the hydraulic system at various places to see where the trapped fluid releases and where it doesn't. When the brake locks up, crawl underneath and open the bleeder screw on that caliper. If it doesn't release there, the new caliper is sticking. If it does release, the next time it happens, loosen the steel line at the master cylinder. If the brake releases from there, the fluid is not being allowed back into the reservoir. Two common causes of that are something is holding the brakes partially applied or brake fluid contaminated with petroleum product. If the the push rod is adjusted too long or the brake light switch is misadjusted, they will hold the brake pedal down too far. Petroleum product in the brake fluid will cause all rubber parts to swell. The lip seals will grow past the return ports and block them. That includes engine oil, transmission fluid, power steering fluid, or even slight grease residue from your fingers. The clue is the fluid pressure will release right at the master cylinder and the rubber bladder seal under the reservoir cap will be blown up and mushy.

I'll run these by my mate in the morning and will post how I get on. If anyone else knows of anything else which could be causing this, I'm all ears.

1.0 Fabia? Are you not in the uk I would assume?

The way to approach this is to open the hydraulic system at various places to see where the trapped fluid releases and where it doesn't. When the brake locks up, crawl underneath and open the bleeder screw on that caliper. If it doesn't release there, the new caliper is sticking. If it does release, the next time it happens, loosen the steel line at the master cylinder. If the brake releases from there, the fluid is not being allowed back into the reservoir.

If you do as suggested above but in the reverse order ie start at the master cylinder, ABS valve etc and work your way towards the sticking brake caliper, you will identify what the cause of the problem is "in one go" instead of maybe having several attempts.

HTH

Bill.

The other cause of a sticking brake caliper is that the piston to caliper body seal goes hard from heat and age! This stops the piston retracting slightly when you come off the brakes! Get a new set of seals and dust skirts for each caliper and when you remove the piston you will find burnt on rubber on the piston. Just give it a clean/smooth with 1500grit wet/dry paper using brakefluid as a lubricant! Then clean up with meths...repeat to the cylinder bore. Just done this to my fronts as they were sticking on me (just after fiting new discs and pads etc!)

Thanks for all the advice and ideas, I think I might have to face the music and take it to a dealer for a diagnostics check. I spoke to a couple of dealers and they said it's possibly either the ABS or pressure release valves.

And apologies, it's a 1.2 (it's the wifes car).