help brakes stuck on
Discussion
Hi,
Got a bit of a problem I changed my front brake pads yester today. All ok. Except went for a drive to bed the pads and rear calipers are stuck on. I am fairly certain its not the handbrake. Have I done something horribly wrong in changing the front pads?
Thanks
Dave
Edit to tidy up the original post that was made from a phone..
Got a bit of a problem I changed my front brake pads yester today. All ok. Except went for a drive to bed the pads and rear calipers are stuck on. I am fairly certain its not the handbrake. Have I done something horribly wrong in changing the front pads?
Thanks
Dave
Edit to tidy up the original post that was made from a phone..
Edited by davido140 on Sunday 2nd March 08:07
davido140 said:
djc1001 said:
Make sure the resevoir not overfull.
New pads pushes fluid back into the system and it is possible to get a system lock if excess fluid does not excape via the breather hole.
David
cool thanks, chek when fluid is hot or cold?New pads pushes fluid back into the system and it is possible to get a system lock if excess fluid does not excape via the breather hole.
David
Cheers again.
David
djc1001 said:
davido140 said:
djc1001 said:
Make sure the resevoir not overfull.
New pads pushes fluid back into the system and it is possible to get a system lock if excess fluid does not excape via the breather hole.
David
cool thanks, chek when fluid is hot or cold?New pads pushes fluid back into the system and it is possible to get a system lock if excess fluid does not excape via the breather hole.
David
Cheers again.
David
if anything its a little low, but still on the dip stick.Think I will bite the bullet and get it transported to Power by the good old AA on Monday!
TY for the help!
It's either mechanical or hydraulic.
If it's hydraulic it is probably temperature related and will ease off once it has cooled down. That doesn't mean you can ignore it, just means you need to be aware of this when you're tracking it down. It's possible for the hose to fail in such a way that it holds pressure on, but this would usually only affect one wheel. There is also a problem which can occur in the master cylinder. The master cylinder should be open to the reservoir when you have your foot off the brakes. The first fraction of an inch of travel closes off the port to the reservoir so the system can build up pressure. People like to adjust this 'dead' travel out by adjusting the pushrod, but if you go too far the port won't ever open. Since the system is then closed, it will build up pressure due to thermal expansion in the caliper when the brakes get hot, so the brakes will start to drag, building up more and more heat until they lock solid. The same problem can be cause by gunge inside the calliper. The easiest way to diagnose this is to get the problem to occur and then crack the bleed nipple on one of the affected callipers. If the calliper unlocks, you know this is the problem.
It could also be that you have failed to clean and regrease the calliper sliders, or left brake dust residue on the rails that carry the pads, so the pads are sticking to the callipers. This would show up as uneven pad wear if you left it long enough, but in the short term just check that the callipers sliders move easily with no slack, and the callipers themselves are clean.
If it's hydraulic it is probably temperature related and will ease off once it has cooled down. That doesn't mean you can ignore it, just means you need to be aware of this when you're tracking it down. It's possible for the hose to fail in such a way that it holds pressure on, but this would usually only affect one wheel. There is also a problem which can occur in the master cylinder. The master cylinder should be open to the reservoir when you have your foot off the brakes. The first fraction of an inch of travel closes off the port to the reservoir so the system can build up pressure. People like to adjust this 'dead' travel out by adjusting the pushrod, but if you go too far the port won't ever open. Since the system is then closed, it will build up pressure due to thermal expansion in the caliper when the brakes get hot, so the brakes will start to drag, building up more and more heat until they lock solid. The same problem can be cause by gunge inside the calliper. The easiest way to diagnose this is to get the problem to occur and then crack the bleed nipple on one of the affected callipers. If the calliper unlocks, you know this is the problem.
It could also be that you have failed to clean and regrease the calliper sliders, or left brake dust residue on the rails that carry the pads, so the pads are sticking to the callipers. This would show up as uneven pad wear if you left it long enough, but in the short term just check that the callipers sliders move easily with no slack, and the callipers themselves are clean.
GreenV8S said:
It's either mechanical or hydraulic.
If it's hydraulic it is probably temperature related and will ease off once it has cooled down. That doesn't mean you can ignore it, just means you need to be aware of this when you're tracking it down. It's possible for the hose to fail in such a way that it holds pressure on, but this would usually only affect one wheel. There is also a problem which can occur in the master cylinder. The master cylinder should be open to the reservoir when you have your foot off the brakes. The first fraction of an inch of travel closes off the port to the reservoir so the system can build up pressure. People like to adjust this 'dead' travel out by adjusting the pushrod, but if you go too far the port won't ever open. Since the system is then closed, it will build up pressure due to thermal expansion in the caliper when the brakes get hot, so the brakes will start to drag, building up more and more heat until they lock solid. The same problem can be cause by gunge inside the calliper. The easiest way to diagnose this is to get the problem to occur and then crack the bleed nipple on one of the affected callipers. If the calliper unlocks, you know this is the problem.
It could also be that you have failed to clean and regrease the calliper sliders, or left brake dust residue on the rails that carry the pads, so the pads are sticking to the callipers. This would show up as uneven pad wear if you left it long enough, but in the short term just check that the callipers sliders move easily with no slack, and the callipers themselves are clean.
Wow thanks for that, interesting reading, from what you have said there sounds like its hydraulic, I had the rear pads replaced by TVR power only 2000 miles ago so im sure they cleaned them up properly, so that leave a slightly dodgey master cylinder (but the fronts are no problem, so maybe not this?) so gunge in the caliper maybe?If it's hydraulic it is probably temperature related and will ease off once it has cooled down. That doesn't mean you can ignore it, just means you need to be aware of this when you're tracking it down. It's possible for the hose to fail in such a way that it holds pressure on, but this would usually only affect one wheel. There is also a problem which can occur in the master cylinder. The master cylinder should be open to the reservoir when you have your foot off the brakes. The first fraction of an inch of travel closes off the port to the reservoir so the system can build up pressure. People like to adjust this 'dead' travel out by adjusting the pushrod, but if you go too far the port won't ever open. Since the system is then closed, it will build up pressure due to thermal expansion in the caliper when the brakes get hot, so the brakes will start to drag, building up more and more heat until they lock solid. The same problem can be cause by gunge inside the calliper. The easiest way to diagnose this is to get the problem to occur and then crack the bleed nipple on one of the affected callipers. If the calliper unlocks, you know this is the problem.
It could also be that you have failed to clean and regrease the calliper sliders, or left brake dust residue on the rails that carry the pads, so the pads are sticking to the callipers. This would show up as uneven pad wear if you left it long enough, but in the short term just check that the callipers sliders move easily with no slack, and the callipers themselves are clean.
Im hoping that TVR Power can look at it sooner rather than later as Im intrigued to find out what the problem is!
dogbucket said:
Maybe when you pumped the pedal to set the new front pads the pressure created in the rear system has not released. Front/rear bias valve do-dah jammed or something?
I was thinking something along those line, force too much pressure in the rear and they need bleeding.Cant be arsed now. garage will fix it!
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