Brakes feel awful

[optimax sniffer]

Having got back from the 'ring and spa, my brakes feel awful. They got warm / hot whilst on the tracks but not as hot as you would expect.

The pedal is solid, but there is no bite at all on the brakes, and a fair bit of effort is required to stop the car.

I fitted the racing green discs last year, along with a set of CL rc5+ pads, and they've done a few thousand miles.

I presume the pads are fine, discs have signs of seeing heat, but look ok.

Servo problems?

[Steve_T]

Sticking pistons?

[C3BER]

What's the fluid like?
Are the pads knackered?

[Gazzab]

Glazing on the pads? I had this on a Le mans trip once. Had to get the pads lightly sanded to take the glazing away.

[optimax sniffer]

I'm going to bleed the brakes and change the fluid, at the weekend. I was going to check the pads too.

Hopefully that will cure it, I'd be surprised, but happy

[billy no brakes]

I would start by bleeding the brakes as you say, you could have boiled the brake fluid but you would have known that straight after you finished your session on track.

If that does not work then it could be your discs are glazed and need grinding down, you will need to take to a specalist for that, check your pads as well

[M3John]

Gazzab said:

Glazing on the pads? I had this on a Le mans trip once. Had to get the pads lightly sanded to take the glazing away.

I'd be checking this first mate.

[spitfire4v8]

If your cerb has a plastic non return valve in the servo vac pipe near the os exhaust manifold check its not melted. Seen that before

[longbow]

It does sound like you've lost servo assistance based on the symptoms. I agree with Joolz, check the servo vacuum hose to the os throttle body and check for melting/damage/splitting etc

[Brummmie]

Servo assistance gone for sure, its the only reason the pedal would go hard.
Pump up the brakes without the engine running, then start the engine, the pedal should sink as the servo adds assistance.

HTH

[gruffalo]

I have a second hand functioning servo off a mk3 fiesta that I am told fits, let me know if you need it or I can get a new one for much less than the £480 that power are asking for one.

[Nickccc]

Hi Ian, happy Birthday by the way.
Just take the pads out and rough up the faces with sand-paper, they are glazed as John says, 100% certain of it.

[FUBAR]

I had very similar symptoms on the Spa trip 2 years ago. Feels like your pushing against a plank of wood? Matt ex SP swapped in Graham's spare CLs trackside and made no difference. Turned put to be a shot brake servo.

[Nickccc]

Yeah I remember, but think about the conditions he has been using the car in.
The Spa track day was cold and grip levels were relatively low, so you end up being much more tentative with the inputs.
You won't be jumping on the brakes like you can in high grip environment ( warm track, with high grip levels) so you end up riding the brakes getting set up for the corners, instead of looking like a bell curve your brake pressure goes on then doesn't really peak as you'll lock the tyres, hench much more time on the brakes whilst not pressing them as hard, result glazed pads.
I bet you a tenner, to the charity of your choice it's pads.

[Brummmie]

Really? Why is the pedal hard?
If the pedal felt the same but you can't stop I'd agree..

Edited by Brummmie on Thursday 4th April 20:13

[Nickccc]

The pedal is solid, but there is no bite at all on the brakes, and a fair bit of effort is required to stop the car.

That sounds like he is saying the pedal hasn't gone soft, so fluid is ok.
I'm not saying it couldn't be the servo, I'm saying I think he has glazed his pads.

[Nickccc]

Pretty sure if you put your foot on the brake with the engine off then start it you should feel the pedal dip very slightly them firm up, if it doesn't firm up then that is would suggest the servo is goosed. Try that and see if you feel the servo kick in.

[camel_landy]

Glazed pads...

...Trust me, I know...

M

[Brummmie]

Nickccc said:

Pretty sure if you put your foot on the brake with the engine off then start it you should feel the pedal dip very slightly them firm up, if it doesn't firm up then that is would suggest the servo is goosed. Try that and see if you feel the servo kick in.

No, it won't sink at all, as its not assisting, it will stay firm.
Glazed pads do happen, but they do not make the pedal go hard, you just won't stop.
Fluid problems pedal goes long, wedged pads pedal goes long.
What charity would I like?

[Nickccc]

I was going to make the same offer to you Paul, we will see when Ian gets out to the garage with his sandpaper, but as it's his birthday today we will have to give him the night off.