Mr C

iTrader: (2)

I've just braked really hard from about 100 down to 30 several times, and the front brakes were stuck on, the brakes are KAD 6pots on 355mm disks and half worn pads, I've got a modified sierra pedal box. I've struggled home and cooled them with 8x buckets of water which freed them up straight away.
As precaution ive removed the pads and cleaned the pistons making sure they're all free moving and no dirt on the piston seals. They work fine still so I was wondering what could cause this? Obviously as they got hot everything expanded and they rubbed more and it expanded more etc etc, could the fluid have boiled and expanded too, can pistons stick when hot? It just wouldn't roll even with 240 bhp behind it. I have no extra brake ducting and it was super hot out but that still shouldn't happen I can't have this happen again, so some ideas please people!

YOREVOL

long shot but have the flexy pipes collapsed internally. i had this on a car years ago. other than that check abs valve block. i cant see a problem with cooling as a six pot calliper should be able to cope with 100mph comfortably.

bunnymofo

dosnt throwing water over hot brakes warp the disks ?

Mr C

iTrader: (2)

I've got braided hoses throughout and they are about 5yrs old. WHAT? I had 2 choices either let the car go up in Flames or I put them out with water?!? They cooled evenly and are still true.
Has nobody else had this? No other ideas?

Mr C

iTrader: (2)

Oh and it's on a pedal box, no assist on the brakes, no ABS
Could sticking master cylinders do the same? They are Girling items and only 2yrs old though.

YOREVOL

have you got the balance set up right? sounds like too much front bias. how warm do the rears get?

Mr C

iTrader: (2)

I can lock the rears with the foot brake if on a light fuel load and bias adjusted to the rear, so the bias I don't think is a problem but the cylinders I will check Tony thanks

Rax

iTrader: (1)

I had the same thing but on a normal brake set up and it was the master cylinder knackered.I had to have a shop keeper fill empty sweet jars up with water because my car was stuck in the main road shit myself like incase the discs exploded or broke.

Mr C

iTrader: (2)

My front brakes stuck on again today, struggled home and have just swapped the front master cylinder. It's now totally stuck in not returning at all. Thanks Tony and all the above for your help