hey guys.. this may be a bit of an essay/story but im getting to a point where my pockets arent deep enough for my garage to 'Keep trying things'... plus i want to see what you guys think.. Its a REAL Puzzler

So here we go.. It's a Skoda Fabia Comfort 2000 reg, done 85,000 miles. Not a bad runner blah blah.

After about 10 mins of driving 2 weeks back i was coming down a hill and front passenger side brake seized on. I left it to cool for an hour or so and it freed itself off. Carried on driving with no issues, didnt seize again for the 100 miles i did, but brake went very spongey, until a point where the brake pedal needed a good clutch like depth to brake.

took it garage they said seized calliper easily sorted. they changed and replaced both front pipes that but couldnt get a brake pedal back. rebled and filled the system, couldn't get fluid out of the driver side front calliper now, but ok with all others. Took the drums off the rear to find blake fluid ****ing out the cylinders.. changed them both and re filled the system.

Still no fluid out of the drivers side front and no brake pedal. Conclusion > master cylinder gone. Changed master cylinder pedal is back.

Took it away, 10 mins in to driving BOTH front brakes seize on and pedal is solid, both rear brakes are fine and free when fronts are seized. They release after about 20 mins when they are cool again but not helpful.

Garage say it could be the MC pin that needs adjusting and they're seizing on because of the heat generated> expansion of B.fluid blah blah which i understand.

The bit i don't get is if the brakes are aligned DSF and PSR, PSF and DSR why are only both front brakes seizing and not seizing across the car? is there away to have connected them Front and Back? which would be causing this? or could it be the M.Cylinder pin?

Literally ANYTHING would be of help right now..

Cheers .. Fletch

"Siezed caliper" usually means "stuck on guide pins" to me. This tends to cause rapid pad wear, but not actually immobilise the car which is what you seem to be saying is happening?

The only way I can see the front brakes locking on hard enough to immobilise the car is if the hydraulic pressure won't release when you take your foot off the pedal. That suggests that the issue must be with the ABS block.

it builds to a point of immobilisation. you dont have to use the brakes for the pressure to build.

Car doesn't have ABS.

Cheap as chips to strip and re build calipers yourself.

I would get new seal kits and pistons from these guys http://biggred.co.uk/ and have ago at rebuilding them. I may have mis read your post but i cant see where they actually fixed the seized caliper... freeing it up doesn't always mean they have fixed it

Also well worth a read,,,http://www.vw-resource.com/pressure.html

Stuck caliper causing pressure in the brake system and trapping fluid in the master cylinder maybe? would explain the brakes locking up and then after a while coming back, the pressure in the cylinder could be returning to normal over time.

Also well worth a read,,, http://www.vw-resource.com/pressure.html

Stuck caliper causing pressure in the brake system and trapping fluid in the master cylinder maybe? would explain the brakes locking up and then after a while coming back, the pressure in the cylinder could be returning to normal over time.

Note that the link (fixed in this quote) discusses a car with 4-wheel drum brakes, and drums typically have much longer travel from "rest" to "full on" than discs do. The idea of fluid not returning from the master cylinder to the reservoir is one I've never heard before, but does fit the facts with a car that has front discs and rear drums.

it builds to a point of immobilisation. you dont have to use the brakes for the pressure to build.

Car doesn't have ABS.

ABS is fitted as standard, what exactly do you mean?

ABS is fitted as standard, what exactly do you mean?

Only after a certain age bud. ABS became standard around 02 if I remember correctly

Mines a 2000 Comfort with ABS as standard, the Elegance is the top spec. and also had ABS as standard, I know the Classic didn't come with it as standard if that's what you mean?

Nope No ABS... or if i have... it certainly doesn't work.. (which i guess may have saved me an insurance claim last year)

They replaced the seized calliper on the PSF but didnt do anything to the DSF.

the symptoms do appear the same as first time, except only the PSF seized last time, the DSF didnt.. Now they both seize.

Sounds like the diaphragm on the servo has come off. How were the brakes bled? You need to use a pressure bleeder as the old fashioned way of pressing the brake pedal will cause the mentioned diaphragm issue. My brother had this happen on his Octavia which caused his brakes to lock on.

Sounds like the diaphragm on the servo has come off. How were the brakes bled? You need to use a pressure bleeder as the old fashioned way of pressing the brake pedal will cause the mentioned diaphragm issue. My brother had this happen on his Octavia which caused his brakes to lock on.

You mean that you need to use a vacumn bleeder because pressure over 15PSI can force air bubbles into places like the ABS block (and I suspect line limitters on non-ABS cars) that you can't get it back out of without computer bleeding.

You mean that you need to use a vacumn bleeder because pressure over 15PSI can force air bubbles into places like the ABS block (and I suspect line limitters on non-ABS cars) that you can't get it back out of without computer bleeding.

vacumn - not right, it is vacuum! Anyway, that is where my Gunson Easibleeder "powered" from a pump up garden pressure sprayer comes in, I could never be bothered dragging a partially deflated wheel around, so I bought 2-off pump up pressure sprayers for use only in the garage, first one provides air at a raised pressure and when undersealing/waxoiling, the second one, connected to the first but with its pump end sealed, contains the medium being sprayed.

You mean that you need to use a vacumn bleeder because pressure over 15PSI can force air bubbles into places like the ABS block (and I suspect line limitters on non-ABS cars) that you can't get it back out of without computer bleeding.

That's the one. It was an eezibleed thing that ran off tyre pressure

ok.. soo update...

Changed the pipe between the servo and the engine (the pipe that keeps the Vacuum in the Servo) and still no joy.

Interesting idea on the Servo diaphragm i like it.. But this doesn't suggest why the brakes or pedal don't build up when being pumped when the car is cold?

Speaking to Skoda now.. see what they say..

bleeding brakes wise.. im not sure how they did it.

Edited 16 May, 201313 yr by Fl3tch

Another update...

When binded... removing the Servo vacuum pipe releases the pressure... there's a Whoosh sound where air rushes in..

Don't quite know how this works.. but by the sounds of it the vacuum isn't releasing?

watching this : http://www.youtube.com/watch?v=KEKMsTAZss4 makes me massively confused as to how this could be happening?

he's suggested to me it could be that the brake light switch is keeping the pedal depressed.