I can’t make any sense of this , i asked the local garage to fit EBC TURBO GROOVE DISCS all round and green pad , back in November I got side swiped just cosmetic really but had to stop suddenly on the dreaded nth cir.
When I got in and started to drive all was good but on using the brakes there was a kind of pumping on the brake pedal diagnosed as warped discs.
So had some pagid discs fitted on fronts and pagid pads.
Last Friday going down the M1 and a van passed me and lost the load on his roof once again I had to stop suddenly and avoid hitting anything once again warped front discs.
Might be a silly question but surely brake discs should be able to deal with this .
I have never owned a car that has had so many discs fitted … can anyone please advise me on this issue or have I just had a load of bad luck.
Yes all is good had everything checked on Saturday all bushes and linkages good and drives straight with no stering wheel wobble drives as it used to until you touch the brakes the faster the speed the worse it is can’t feel anything on the pedal unless you use it over 40 mph, mind you forgot to mention I was doing approx 50mph then down to 0 in 20 mtrs
Most common issue is the slider pins seizing in the caliper hub carrier and it happens on MX5s a lot because of how many of them are a second car and over winter most of them spend lots of time sat waiting for a sunny day. I’d replaced my front calipers last year and regreased the slider pins when I did it. Changed the pads 3 weeks ago and one of the slider pins was seized in so much I had to take it to a local garage to free it off. If one or both of the slider pins seize then the majority of the braking effort is only applied to one side of the disc heating it more on that side which will warp it.
Thanks for the replies but the car has been used daily average mileage of 400miles a week with no issues at all maybe I’ve just been unlucky with sudden stops from high speed all was ok with the pagids until Friday so maybe travelling for long distances then suddenly hitting the brakes may have caused this not sure ???
It is possible that you have a sticky caliper thus making overheating of the disc easy and quick resulting in the deformation. Check the temperature of each wheel after a drive where you have not used the brakes much just to make sure. Take care not to burn yourself.
Not a bad idea I’ll check it when I get to work after a 40 mile drive lol good news though at least Euro car parts have 50% off brakes so for £140 i can get new brembo discs and pads for front and rear and get rid of the turbo grooves on the rear so it all looks nice and balanced again.
If you are genuinely getting issues with the discs it can be due to hub run out of damage on the hub mounting face. It can also be down to a very overlooked fact that the wheel mounting face is not flat so if you have wheels that have been repainted and there is paint on the mounting faces that will, over time, pull the disc out of shape.
Judder is usually caused by thickness variation in the disc due to poor pad material transfer. It is rare to be a great issue on road pads as they don’t need bedding in like harder pads but if you are prone to sitting with your foot on the brakes at lights, especially after braking then it can have an affect.
No do not waste your time doing 40 miles then checking them as this will not be a controlled trial as you cannot control your use of the brakes over that distance.
Take the car on say a 1 mile run without using the brakes and there should be virtually no heat in the discs. Then 2 miles without using the brakes. Again, check the temperatures. At most 25C
If no real temperature increases then you need to increase it to 10 miles but watch the use of the brakes, then 20 miles.
To do this you need an IR thermometer and point it at all the discs the opposite side from the caliper. Something like this. Buy the higher temperature unit.
Take a note book with you and write down the temps of all the wheels and report back. You have a faulty braking system and the fault needs to be found and sorted.
I can see that … I think but the fact is twice i had to stop suddenly and that’s when it started so really not sure but its happened twice now and straight after an emergency stop its doing my head in now. I have had my wheels repainted but that was over 12 months ago with no issues and in the space 4 months two sets of front discs
I am no mechanic so wouldn’t presume to offer advice so this is just a random thought arising from your description of the symptoms. Could it be a fault in the ABS system either with the sensor or mechanical bits?
Abs has been checked no fault codes came up abs toothed rings also checked no issue there.l have had the abs come on on other cars I’ve owned and that is a a proper pulse can’t really mistake that but the abs did not kick in on this car both times it was more of a controlled heavy braking without the locking up or abs kicking in
Just a thought looking at my nc manual I noticed the top guide pin on the front caliper is all silver and the bottom pin has a black plastic sleeve, and the rear caliper pins are silver top and bottom can anybody confirm this please ?
On the mating face of the hub and disc no there is no paint, on the mating face of the disc and inside of the wheel there maybe, but how would this affect the brakes as the brake caliper and bracket are bolted to the hub assembly the disc is located in place with the locating screw then the wheel sandwiches the whole unit together…so my thinking is if there was paint between the hub surface and the inside of the disc then I could see this maybe being an issue.
Could anyone confirm the guide pin question I posted earlier please.
The sliders sound right to me. 1 rubber sleeve on the front.
With regards to you original concern. Get the runout of the brake discs checked. If it‘s out of spec have the discs machined with an on the vehicle type brake lathe.
Not sure what MK MX5 you have but if it is a MK3 or a MK2.5(big brakes not standard), one of the slider pins on each front caliper has an inset cut into it on the shaft torwards its bottom end accommodating a short length of rubber sleeving.
Any foreign body between the mating faces of the disc and hub will cause issue where the disc will mount but likely run warped. Even grease or brake dust can cause this. Important that both hub face and inner mating face of brake discs are clean and free of any corrosion that will create a raised area anywhere on the mating face area.
Thanks guys for all your replies latest news is there is no heat build up on discs or wheels when driving unless brakes are applied so I take it there is no binding…when the brakes are used there is no pulling to left or right (I don’t do the work myself )so back to the caliper pins as far as I am aware the car is completely standard mk3 08 and standard calipers so the fronts would have two silver pins and the rear ??? Info is not for me to start stripping it down just so I can ask the garage to check everything again. Btw the car had new discs and pads 4wks ago and all was good till friday