give the pedal some more clearance and try racing brake fluid.
depending on what type of wheel bearings you have,you can slacken them off a little to allow the disc to push the pads back a bit more.
Hi.
I have the following problem:
Sunday I went to a trackday. 3 x half an hour, separeted by 1,5 hours brake.
It was a more or less rainny day.
In the last run, after 4 or 5 laps, the car felted sluggish; it just didn't accelerate like it used.
I went to paddock and found front brakes smelling quite a lot, wheels' centre felt really hot, and bleed valves showed humidity around'em.
There were fumes exiting the callipers.
Reservoir was still full.
I went to the trailer, not before kicking quite hard 2 or 3 times the brakes. After that they felt loose again.
As it was raining, the brake into corners was quite gentle compared to the dry days, where I really hit the brakes in the last few meters.
My setup is
Remote double reservoir
Double master cylinders (front / rear) - Wilwood
Brake bias bar
MNR pedal box
Any comments on what could have happened?
Thanks in advance,
Joao
Brake hoses gone soft? I believe they can breakdown and work like a one way valve (don't know if there is truth in this)??
Dan
Was that one brake or all of them?? Sounds like they are binding for some reason - maybe the master cylinder isnt returning and allowing the calipers to release properly.
Brakes overheated and boiled the fluid?!!?
quote:
Originally posted by Steve G
Was that one brake or all of them?? Sounds like they are binding for some reason - maybe the master cylinder isnt returning and allowing the calipers to release properly.
quote:
Originally posted by BenB
Brakes overheated and boiled the fluid?!!?
Overfilling the master cylinder reservoir could well be the problem i guess. I'd try a quick pedal press on each caliper with a bleed hose on to
release any pressure and push the excess fluid through and see how they go.
It doesnt take much pressure there to cause them to start to overheat - and the warmer they get the more thermal expansion of the disk will make the
problem worse.
Possibly not enough free play in the pedal, I've seen this before, initially OK then start to bind.
discs get hot and expand,fluid boils and expands?
give the pedal some more clearance and try racing brake fluid.
depending on what type of wheel bearings you have,you can slacken them off a little to allow the disc to push the pads back a bit more.
Very simple --- I have covered this prpblem at least a dozen times.
Master cylinder piston is not coming fully back.
If the piston dosen't come fully back even by as little 0.5mm the port which allows the the master cylinder bore to vent to the resevoir is
covered by the piston and sealed off.
If the master cylinder bore is shut off from the resevoir when the brakes warm up the fluid expands and the excess fluid cannot vent back to the
resevoir as a result the hydraulic pressure increases forceing the pads on to the disc.
As a result more heated is generated the fluid expands more and the cycle continues untill the brakes jam solid.
The usual causes is either the master cylinder pushrods are too long (there is a lot of bad info on setting dual pedal boxes out on the web) or
washer under the wirclip at the end of the mastercylinder is fouling the the mushromm end of the pushrod.
[Edited on 12/11/09 by britishtrident]
It could be a non-releasing MC. If the brakes got too hot the fluid would boil and expand, pressing the pads against the disc, thereby worsening the problem etc etc etc. But it's a question of why (if this is what happened) the brakes got too hot in the first place... Were you doing heal+toe?
quote:
Originally posted by britishtrident
Very simple --- I have covered this prpblem at least a dozen times.
quote:
Originally posted by BenB
It could be a non-releasing MC.
quote:
Originally posted by BenB
Were you doing heal+toe?
) i had exactly the same proplem...turned out to be what british trident has already said....master cylinder wasnt returning far enough.
quote:
Originally posted by BenB
It could be a non-releasing MC. If the brakes got too hot the fluid would boil and expand, pressing the pads against the disc, thereby worsening the problem etc etc etc. But it's a question of why (if this is what happened) the brakes got too hot in the first place... Were you doing heal+toe?