I’m looking for technical help or recommendations on: __
Had an increasing judder on braking recently so got new front discs to fit. Taking the brakes down found one slider pin perfect (top) and the other seized. Took an hour of penetrating fluid and an impact wrench to get it free! Bizarre to me that you could get the two pins in such different condition in the same caliper.
Instead of fitting the new disc I put the old setup back together to see if this was the source of the judder. It wasn’t sadly.
I had the same problem on my TT. It can be caused by overtightening the wheel nuts apparently, though I mostly finish with my torque wrench I’m wondering if I am the problem here?
If you’re using your torque wrench correctly and it’s not gone out of calibration then how can you be the cause? Also, I’ve never heard that over tightening of wheel nuts can cause excessive disc runout or variation thickness, certainly not on an MX-5 anyway.
I was saying l mostly use a torque wrench. When I’m not Mr Sensible it’s an impact wrench.
As it’s happened on both cars l mostly work on it seems a possibility?
I’m just posting on stuff I’ve done on the car that might stop others making similar mistakes. I’m pretty new to stuff like discs and water cooling having spent most of my life on classic bikes.
The thing that interested me most was that two sliding pins in the same caliper, just three/four inches apart can be in such different conditions: one slippery and one seized.
I’m obviously a silly nerd - just pay the man and shut up
From memory one of the slider pins is plain metal and the other has a rubber surround. If incorrect grease was used to lubticate the sliders maybe the rubber might have reacted an swelled.
Another and more likely possibility is one of the rubber boots failing and letting in water/dirt.
Can you describe the judder and the conditions which cause it to appear?
I’m going to have to ask a mod to make a sticky at this point, I feel like most of my posts are asking someone to actually provide some detail to their “judder, tick, knock, rattle” posts…
Other caliper checked today and is fine. All rubber seals good and in situ. However the offending pin had rusted but not pitted so cleaned up with 400 grit, copper slipped and replaced.
New discs and pads almost half the price of those for the TT !
Judder appears as soon as the car has gone a mile or so.
I can’t comment on why the judder is still present but using copper slip on the slide pins is a no no!
You should use something like red rubber grease, it’s kinder to the rubber boots on the caliper.
id agree get yourself some correct brake grease, copper just seems to make things stick even worse.
Cant see it being the discs etc if the judder appears when warm.
Is it an Abs car?
Just to say the front are excellent despite being just £70 for both discs & pads. Just had to do the rears because of delaminating. Another £70. Such an easy job too either end. My TT is going to be for sale. So much more expensive on parts(for no good reason I can see) and stupidly complicated/ over-engineered when I do jobs that compare.
Its really worth sevicing the pins every couple of years or even annually if the car doesn’t get much use. Its a quick and easy job and you can inspect the pads and other bits and pieces at the same time. Its also useful to bleed the calipers whilst the wheels are off.
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Did the brake fluid recently using a pressurised set-up with a spare tyre providing the pressure. About a tenner for the kit off eBay. Very easy one man operation.
Yes, they are very easy brakes to work on so an annual inspection/service is not a chore.
There are plenty about. Come with a couple of cap sizes. Mine was a bit faulty so araldited the leaky bit so it will now handle more than the advised 20 PPSI. Tedious to set up but a breeze to use if yer on yer own.
