Brakes stuck solid!!!!
Discussion
I haven't been able to drive my car for a week and a half so took it out today for a run. Unfortunately the car wouldn't move.
Over the last few months, the brakes appear to be sticking to the discs, so when trying to drive off, the car needs a hefty shake back and forth to free the brakes. It's been getting progressively worse, and today I had to practically shag the clutch out just to free the brakes. I'm talking 10-plus times going from 1st to reverse and applying a little bit of power.
My smart car also suffers from this, but the brakes will free up just from rocking back and forth in the driver's seat.
I always try to use the brakes before stopping to dry any surface water off the discs. I also leave the car in gear and only have the handbrake on the minimum setting to stop the car. Regardless, it's getting worse and definitely damaging the discs (pad material is being left stuck to the disc).
What concerns me most is whether I'll end up breaking anything by having to slip the clutch just to free the brakes - the clutch ends up burning and then there's a loud 'twang' as the brakes release.
NB the brake discs and pads were replaced with new OE gear mid way through last year.
Can anyone explain whether the handbrake uses different pads to the normal calipers - if so, then the normal brake pads are sticking to the discs for some reason, even when not pressurised...
Over the last few months, the brakes appear to be sticking to the discs, so when trying to drive off, the car needs a hefty shake back and forth to free the brakes. It's been getting progressively worse, and today I had to practically shag the clutch out just to free the brakes. I'm talking 10-plus times going from 1st to reverse and applying a little bit of power.
My smart car also suffers from this, but the brakes will free up just from rocking back and forth in the driver's seat.
I always try to use the brakes before stopping to dry any surface water off the discs. I also leave the car in gear and only have the handbrake on the minimum setting to stop the car. Regardless, it's getting worse and definitely damaging the discs (pad material is being left stuck to the disc).
What concerns me most is whether I'll end up breaking anything by having to slip the clutch just to free the brakes - the clutch ends up burning and then there's a loud 'twang' as the brakes release.
NB the brake discs and pads were replaced with new OE gear mid way through last year.
Can anyone explain whether the handbrake uses different pads to the normal calipers - if so, then the normal brake pads are sticking to the discs for some reason, even when not pressurised...
Don said:
I'd get this checked out. IIRC the handbrake is often a seperate drum-based system not associated with the discs.
In the mean-time...can you just leave it in gear?
How secure is leaving the car in gear? I don't usually have anywhere perfectly flat to park the car, it's always on an incline with plenty of other cars. I wouldn't want it to roll off anywhere.
Presumably it's best to leave it in 1st or reverse?
cyberface said:
I'd get this checked out. IIRC the handbrake is often a seperate drum-based system not associated with the discs.
In the mean-time...can you just leave it in gear?
How secure is leaving the car in gear? I don't usually have anywhere perfectly flat to park the car, it's always on an incline with plenty of other cars. I wouldn't want it to roll off anywhere.
Presumably it's best to leave it in 1st or reverse?
Indeed 1st or Reverse. Reverse if facing down the hill, 1st if facing up the hill and your front tyres turned such that the car would turn into the kerb.
I had a Renault 12 TS with virtually no handbrake for a few months living in Bristol! Parking on a hill was a nightmare...but could be done by leaving the car in gear in the manner mentioned - given the hill is not so steep as to turn the engine over.
Some of the hills I left it on were very steep and it was fine.
So will this work on *your* car? Dunno. Try it whilst *in the car* and see. I suspect it will be fine.
Disclaimer: You must satisfy yourself that this procedure is safe for *your* car and where *you* park. And get your handbrake checked.
The simple check is for me to leave in gear with handbrake off: if the brakes are still stuck next time round, then there's something bizarre happening.
Then again, this just may be my car trying to tell me that it really fancies being upgraded to Big Reds, now it's got a bit more poke.
Then again, this just may be my car trying to tell me that it really fancies being upgraded to Big Reds, now it's got a bit more poke.
It sounds like you are suffereing from calliper plate lift which is common with the type of calliper in your 993 (same as my 944 Turbo S).
The pads slide back and forth on a stainless steel plate, which is screwed onto the alloy calliper. Over the years, corrosion builds up under the plate so they lift and squeeze on the brake pads. In time this will stop the pads moving in and out smoothly, hence causing your seizing problems.
Its about 4 hours labour to remove the plates from all callipers, clean the corrosion and refit them. If you put it off too long (like I just did) then you'll also need new pads and disks all round because they get too rusty too
The pads slide back and forth on a stainless steel plate, which is screwed onto the alloy calliper. Over the years, corrosion builds up under the plate so they lift and squeeze on the brake pads. In time this will stop the pads moving in and out smoothly, hence causing your seizing problems.
Its about 4 hours labour to remove the plates from all callipers, clean the corrosion and refit them. If you put it off too long (like I just did) then you'll also need new pads and disks all round because they get too rusty too
diver944 said:
It sounds like you are suffereing from calliper plate lift which is common with the type of calliper in your 993 (same as my 944 Turbo S).
The pads slide back and forth on a stainless steel plate, which is screwed onto the alloy calliper. Over the years, corrosion builds up under the plate so they lift and squeeze on the brake pads. In time this will stop the pads moving in and out smoothly, hence causing your seizing problems.
Its about 4 hours labour to remove the plates from all callipers, clean the corrosion and refit them. If you put it off too long (like I just did) then you'll also need new pads and disks all round because they get too rusty too
excellent - sounds like I can sort it completely. Given the labour charge, would it make sense to throw the pads anyway and uprate them, keeping the standard 993 calipers and discs? I want to uprate the brake system slightly to compensate for the engine, without having to spend a fortune... next planned large expenditure is a new clutch and I thought I may as well get the lightweight flywheel while I'm at it....
Recommendations for pads? I'm looking for higher performance when necessary than the OE pads, but don't want low-speed squeal like Mintex 1144s and the like.
t urbo said:
Cyberface,
Is this happening after you have washed the car then stored it, if so then this would be normal for the brakes to seize.
After a wash they need to be used a few times if you are not going to use the car for a few days.
This isn't after washing the car, and also if you mean 'storing' it in a garage, unfortunately I don't own a garage so it is parked outdoors.
I'm aware of leaving wet brakes standing, I do try to dry them off before parking up if it's raining outside. However it didn't do this when I first bought the car (and my 2 other 993s didn't do this either), whereas it has been getting progressively worse.
I'm also surprised that the brake pads would sieze when they're not actually being applied to the discs (i.e. the handbrake isn't using the main brake circuit), which the caliper plate corrosion would explain.
Any other ideas re: uprated pads?
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