I’m looking for technical help or recommendations on: Binding Brakes when hot
I’ve been battling an issue with a binding driver side front brake, it doesn’t get that bad during regular driving but during intense braking it gets noticeably hotter than the opposing side to the point that if i’m on a winding b-road and properly going for it, it starts to smoke. I’ve greased the sliders, no issues there, replaced the caliper, no issues there, replaced the flex hose, no issues there and the last thing i’ve tried is filing down the new brake pads (new pads and discs last saturday) i’ve fitted as they were a little stiff in their mounts.
At this point i’m completely at a loss, there is no reason whatsoever for this to keep sticking, could it be an ABS fault or something along those lines, the issue seems to have come on after i replaced the front discs and pads. I’m supposed to be driving it 2000 miles in a week and half so any reccomendations on things to try would be greatly appreciated as this is the only time in close to 30k this car has let me down.
Edit : it only sticks on when it’s hot, it doesn’t bind when i check it cold, only when i really rag it and then check it
Just as an experiment - try removing the rubber sleeve on the slide pin and have a drive.
That will prove it is or is not the sleeve reacting to the lube you used.
No difference unfortunately, @richardn was correct, the Cera Tec stuff was not good to use on the sliders and caused the rubber to seize after it had been left for the day, but with that bit of rubber removed from the slider and the correct red rubber grease used it made no difference, it’s weird as well as it doesn’t get hot unless i use the brakes, if i’m just cruising along it doesn’t heat up at all, it’s only during intense braking, i don’t know if i’m just losing my mind.
I’m wondering as it doesn’t get anywhere near as hot anymore if it’s related to the fact that the wheel is right besides the exhaust manifold and that’s heating it up, i’m going to buy an IR thermometer tommorow and see what the actual temps are.
So - having exhausted pretty much everything else :
Caliper replaced & piston moves easy hot or cold
Pins slide easy
Discs & pads replaced
Flexi hose replaced
The only other thing in the system is the ABS pump.
When you replaced the flexi hose - did you only bleed that corner ? - or the full system ?
Just trying to work out if the right side is doing all the work and perhaps it is the left that has the fault.
I would be tempted to take it in to an mot station and have them do a brake test on it.
That will tell you if the brakes are equal pressure across the car.
Good shout with the MOT test station, at this point it’s just completely braking my brain, i have never been so stressed out in my entire life over a car, the car has been absolutely faultless for like 2 years, multiple trackdays and 30k miles and then the one time i really really really need a holiday and i’m supposed to be driving it 1500 miles to scotland it just completely lets me down.
I’m going to spend a lot of my work brakes tommorow frantically calling garages to see if anyone can look at this for me, it’s cost me so much of my sanity.
Hi Z,
If you can get the brakes binding and then crack the bleed nipple on the offending calliper to see if this releases the pressure it may help to identify the problem. plus caus you are stressed
You replaced all the rotors? Have you checked that your problem side does not have a badly seated or slightly warped rotor? Is it worth swapping them side to side and see if the fault moves to the other wheel?
The brakes don’t fully bind so it’s difficult to actually notice if it makes a difference, it certainly does not spurt out of the bleeder like i’ve seen it happen before and as it generally isn’t seized that much i’m hard pressed to tell if it makes much of a difference until i’ve got the wheels back on and by that point it would have unseized anyway.
From what i know of the MK3 it’s a diagnonally split system, and i do know that in the past i have experienced issues with the rear left hand corner (diagonally opposed from the affected corner) seizing and causing the rear left inside pad to wear down to the backing plate, only recently i just had the rear left brake sliders dismantled and cleaned (asked them to replace the caliper but they said it wasn’t needed and so just cleaned it and greased it) so not sure if it could potentially be related to that, is there any thing i can try with the rear left wheel do you think?
Yup all front rotors are replaced, they do seem to be straight and true with no uneven deposits visible on the surface, i could try moving the front discs to the other wheel however the issue there is that i’m only able to raise one side of the car at a time so i would need to try and find somewhere flat to actually do it.
I don’t think the left rear wheel could be causing any problem with the front, but the combination could be a pointer to problems around the master cylinder in the absence of the usual suspects.
plus 