brakes sticking
Moderator: phpBB2 - Administrators
brakes sticking
Hi all, my car has a remote servo on a single line braking system, all callipers, wheel cylinders, master cylinder and servo are new.
When i press the brake pedal lightly, they stick on slightly (all 4 wheels) and eventually (3secs or so) come off again. Alternatively, when they are slightly stuck on I can release them by pressing hard on the brake pedal. Does anyone have any ideas about what is going on?
Thanks for any help.
When i press the brake pedal lightly, they stick on slightly (all 4 wheels) and eventually (3secs or so) come off again. Alternatively, when they are slightly stuck on I can release them by pressing hard on the brake pedal. Does anyone have any ideas about what is going on?
Thanks for any help.
- topcatcustom
- Forum Contributor
- Posts: 2965
- Joined: Sat Aug 09, 2008 11:53 am
- Location: Essex
- Contact:
Hi
Do you have a residual pressure valve in line?
Do you have any really tight bends within your system and have you made the hard lines up yourself?
Also did you check that the pistons within the calipers are moving freely without the pads in place?
You can pop the pads out and put a thin block of wood between piston and disc and pump the pistons out and back several times to free everything up.
Sometimes the pistons will get a sort of rind between the seals and this takes a few in and outs to free up.
Hope this helps.
Cheers
Paul
Do you have a residual pressure valve in line?
Do you have any really tight bends within your system and have you made the hard lines up yourself?
Also did you check that the pistons within the calipers are moving freely without the pads in place?
You can pop the pads out and put a thin block of wood between piston and disc and pump the pistons out and back several times to free everything up.
Sometimes the pistons will get a sort of rind between the seals and this takes a few in and outs to free up.
Hope this helps.
Cheers
Paul
Hi Again
I'm assuming that the braking system is a matched unit from one supplier.
Have you checked that the pedal ratio is correct for the M/C you are using.
It may be possible that you have a dodgy seal on one of the cylinders that is allowing the fluid to back feed and causing this sticky problem.
Also how many outlets do you have on the cylinder from the servo?
Cheers
P
I'm assuming that the braking system is a matched unit from one supplier.
Have you checked that the pedal ratio is correct for the M/C you are using.
It may be possible that you have a dodgy seal on one of the cylinders that is allowing the fluid to back feed and causing this sticky problem.
Also how many outlets do you have on the cylinder from the servo?
Cheers
P
- Ian Anderson
- Forum Contributor
- Posts: 2396
- Joined: Sun Nov 19, 2006 9:46 pm
- Location: Edinburgh
I'd hazard a guess
The seal in the master cylinder is sticking in the "on" position
It can do this so long as there is not much pressure to push it back (Normally also have a spring also pusjing the seals back)
So stand on the pedal and the pressure is "big" so it will push the seal back - gentle and the seal will not move.
It could work itself loose
Or it could be an indication of seal failure - some seals do not like certain brake fluids - get the wrong 2 together and the seals will swell before collapsing
Could be worth a call to Wilwood to check if the fluid you used is compatable
Ian
The seal in the master cylinder is sticking in the "on" position
It can do this so long as there is not much pressure to push it back (Normally also have a spring also pusjing the seals back)
So stand on the pedal and the pressure is "big" so it will push the seal back - gentle and the seal will not move.
It could work itself loose
Or it could be an indication of seal failure - some seals do not like certain brake fluids - get the wrong 2 together and the seals will swell before collapsing
Could be worth a call to Wilwood to check if the fluid you used is compatable
Ian
Owner of an "On the Road" GT40 Replica by DAX powered by 3.9Hotwre Efi, worked over by DJ Motors. EFi Working but still does some kangaroo at low revs (Damn the speed limits) In to paint shop 18/03/08.
Was the servo at fault, even though new! Ran a pipe to bypass the servo, bled brakes and took it on a run, no locking on and no more 'notchiness' (yes I know its not a real word) through brake pedal. Company replaced servo, fitted today and brakes now feel superb and pull up well Thanks for all your help guys.