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Osf brake caliper purple!

4.1K views 37 replies 9 participants last post by  R26.R Steve  
#1 ·
I had problems with my nsf caliper a month or so back, but thought that was all sorted.

I was getting brake judder on track on thurs but put it down to the rc6 pads

Just washed the car today and the osf caliper is purple in colour basically!

I can only assume its because the nsf caliper has either stopped working or is working very little so the osf caliper has taken all the abuse from the day.

Think im gona send both off for full refurbs anyway but can anyone think of any other reason why they might be playing up?

Brakes are still very strong, good pedal feel, no leaks...
 
#8 ·
Update:

Im no mechanic and cant remember exactly was i was told but went into renault today

Was told the piston/pad was sticking and had fried the piston seals, ruining the caliper, pad and warping the disc.

Nearside caliper was okay but im not risking it so 2 new calipers, new discs, new pads and new fluid all bought... Expensive day!
 
#10 ·
Starting to get a little annoyed now

Fitted new discs, pads, calipers and fluid. Obviously brakes are going to be pretty poor first few hundred miles but thats not my concern.

After a subtle drive tonight i got out to have a nosy, i felt the osf caliper (original one that overheated) and that was too hot to touch after 5secs wheras the nearside one was just 'hot' and i could leave my finger on it.

Is there a way the nsf brakes are working less than the osf overloading the osf? Even though ive replaced everything?

Cheers
 
#14 ·
Right, the osf caliper is noticably hotter than the left after a drive.

All internet info points to a grabbing pad, possible causes:

Piston sticking - causing pad to get stuck against disk causing hit build up
Pins not sliding correct - causing pads to get stuck

Or

What i think

Hoses - hydraulic pressure build up meaning the piston cant return causing pad to grab on disc.

Coincedentally the osf caliper (hottest one) was the one ive just fried and about 1 month before i fried it on track, i fitted goodridge braided lines.

Is it plausible for me to say the goodridge osf line could be faulty/incorrect diameter causing this pressure buildup?

How do i know thats the cause if it is? Shall i go back to standard lines? Do i contact goodridge with my issue?

Cheers
 
#15 ·
What I would do mate is put car on axle stands. Start car, get someone to press the brake pedal. Then let go of the brake. See if you can turn the wheel or disc by hand. If its tight open the bleed nipple and see if the disc gets easier to turn. If it does its pressure build up. You could also try this by opening the the connection where it joins the brake pipe to brake hose. This would determine whether it is a faulty hose or caliper. (Fords uses to have problems with hoses collapsing inside causing the same symptoms as you describe. Usually after some heavy braking)
If it doesn't get any easier to turn the disc then your pads are stuck in the sliders. That's simple to check, just try taking them out like when you replaced them.

I hope this makes sense to you?? It is early in the morning writing this. Let us know how you get on
 
#21 ·
im going through the same issue at the moment osf front calliper has got so hot is destroyed the seals :( however the wheel still spins fairly freely and the pads move easily on the pins and inside the calliper itself! never had this before so i guess its down to the pistons not retracting :(
 
#25 ·
Yup thats the next thing, luckily i kept the std hoses!

Gona do them one night this week weather dependent and ill report back any change.

To me there is no other excuse, if done calipers, discs, pads and fluid and bled every bubble i can out and still the same so to me, the hose (im guessing here) is probably faulty or slightly too small causing it to hold pressure and not release the pistons back

Fingers crossed as i dont want to fund this again!