Paul372 Posted June 17, 2018 Share Posted June 17, 2018 Hi, I’m running uk spec four pot calipers on my jap spec tt auto with Oem discs and pads but the problem is that I keep warping the discs I’ve been through two sets now. So what make discs and pads are you guys using and what’s the best set up for discs and pads for uk spec calipers Quote Link to comment Share on other sites More sharing options...
jagman Posted June 17, 2018 Share Posted June 17, 2018 If you hammer the brakes and come to a stop , put the car in N and use hand brake , coming to a stop and leaving your foot on the brake to stop the car creeping forwards could cause warpage as the pads pull heat out of the disc on contact area and disc cools unevenly . You would have to hammer the brakes to do this though , sure your pistons are moving evenly ? Quote Link to comment Share on other sites More sharing options...
ripped_fear Posted June 17, 2018 Share Posted June 17, 2018 If you hammer the brakes and come to a stop , put the car in N and use hand brake , coming to a stop and leaving your foot on the brake to stop the car creeping forwards could cause warpage as the pads pull heat out of the disc on contact area and disc cools unevenly . You would have to hammer the brakes to do this though , sure your pistons are moving evenly ? This...or maybe a wheel bearing? Quote Link to comment Share on other sites More sharing options...
Paul372 Posted June 17, 2018 Author Share Posted June 17, 2018 Capliers are fine they was refurbished last year and had a couple of the pistons replaced because they where slightly pitted Quote Link to comment Share on other sites More sharing options...
Paul372 Posted June 17, 2018 Author Share Posted June 17, 2018 How would I go about getting the calipers checked Quote Link to comment Share on other sites More sharing options...
SupraLEDrears Posted June 17, 2018 Share Posted June 17, 2018 following Quote Link to comment Share on other sites More sharing options...
jagman Posted June 17, 2018 Share Posted June 17, 2018 The pads should have even wear , and surface even surface wear , the pads should retract clear of the disc on both sides ie the heat is evenly spread across the disc and no bap bap bap noises on braking Quote Link to comment Share on other sites More sharing options...
evinX Posted June 17, 2018 Share Posted June 17, 2018 I had no end of trouble with OEM uk discs and pads making noise, i ended up going for Mtec discs and Mintex pads. Wont ever consider Toyota again. Quote Link to comment Share on other sites More sharing options...
Paul372 Posted June 17, 2018 Author Share Posted June 17, 2018 I’ve got no noises at all coming from the brakes the discs are just warped, it’s horrible when braking you can feel it through the brake pedal and the steering when braking, I just don’t think that the Oem discs can take a lot of heavy braking Quote Link to comment Share on other sites More sharing options...
evinX Posted June 18, 2018 Share Posted June 18, 2018 I’ve got no noises at all coming from the brakes the discs are just warped, it’s horrible when braking you can feel it through the brake pedal and the steering when braking, I just don’t think that the Oem discs can take a lot of heavy braking I remember someone saying either front or rears have been known to come warped from toyota! Bloody shame toyota brakes and discs actually arnt that good Quote Link to comment Share on other sites More sharing options...
Burna Posted June 18, 2018 Share Posted June 18, 2018 I have never warped any UK sized stock Toyota discs, and I really hammer the brakes hard. I feel you have an underlying problem that's causing you to warp discs, wheel bearing perhaps? For years now there's been a problem with facelift Supra's warping disc's over and over again, Pete, Branners are two members that have/had this problem. We've never gotten to the bottom of it. Quote Link to comment Share on other sites More sharing options...
Dnk Posted June 18, 2018 Share Posted June 18, 2018 Never had a problem with UK OE discs/pads, even after track days Certainly not heard of them coming warped, find that hard to believe tbh Quote Link to comment Share on other sites More sharing options...
TheTurtleshead Posted June 18, 2018 Share Posted June 18, 2018 Sounds like front wheel bearing, or the hub faces aren’t clean when you put the discs on. Quote Link to comment Share on other sites More sharing options...
Ark Posted June 18, 2018 Share Posted June 18, 2018 Are you sure it's warpage? Pad deposits can create the same shuddering feeling. Having said that I (thought I) warped lots of sets of stock disks on my facelift model. Eventually fitted APs and never looked back. Quote Link to comment Share on other sites More sharing options...
Scooter Posted June 18, 2018 Share Posted June 18, 2018 Sounds like front wheel bearing, or the hub faces aren’t clean when you put the discs on. Possibly this, if you can get one of those 'dial gauges' I think it's called.......think of like an old vinyl record stylus, you fit the disc with all 5 wheel nuts and then rotate it with this gauge contacting the disk face and you will see the dial fluctuating, sometimes a reclean and rotating the disc one stud round etc can even it out, at least then you are starting from as true as possible. Quote Link to comment Share on other sites More sharing options...
Dnk Posted June 18, 2018 Share Posted June 18, 2018 DTI or dial test indicator Quote Link to comment Share on other sites More sharing options...
Scooter Posted June 18, 2018 Share Posted June 18, 2018 That's the kiddie! Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted June 18, 2018 Share Posted June 18, 2018 I see hub flanges warped from ill fitting wheels being overtightened. If the hub flange has run out then so has the disc. As stated above, a DTI on the disc and then on the flange will tell the tale. The hub flange can be trued uo in a lathe, but it's a bit of a PITA, i would recommend getting a new one if one or more have warped. Discs can be surface ground back to true. Quote Link to comment Share on other sites More sharing options...
nigelboyne Posted June 18, 2018 Share Posted June 18, 2018 You wouldn be steam cleaning car when brakes are hot? I have seen wrapping caused by this hot discs cold water. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted June 18, 2018 Share Posted June 18, 2018 Another thing that can cause front brake judder is tired inner wishbone bushes or a tired bottom ball joint. Mainly the former. Quote Link to comment Share on other sites More sharing options...
SupraLEDrears Posted June 18, 2018 Share Posted June 18, 2018 Another thing that can cause front brake judder is tired inner wishbone bushes or a tired bottom ball joint. Mainly the former. Im replacing my front upper and lower wishbones because I'm struggling with high speed vibration and brake vibration. Even after replacing the discs, brake pedal vibrations happened with new discs and a loud knock when braking hard. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted June 18, 2018 Share Posted June 18, 2018 (edited) Check the caliper pistons are retracting after a hard brake application with the engine running to give servo assist, with the front wheels off the ground. If the wheels do not rotate very freely due to brake bind the pistons are not free enough for the deliberately shaped seal recesses in the caliper bores to retract the pistons from the pads a few thousandths of an inch. This will cause uneven piston pressures on the disc which in turn causes "strange things" to occur. The seal grooves DO NOT have a flat bottom, the bottom of the grooves are chamfered at an angle to deform the seals in brake application and their hysteresis should retract the pistons a tad when the brakes are released. Get someone to watch the front tyres and wheels within the front arches when you hit the brakes hard at a fast walking pace. If they move back more than a bit in the arches the wishbone bushes are shot, and any brake imbalance or slight (and normal...) frictional changes between pads and discs will start an oscillation (judder) at certain speeds. Older BMW's were notorious for this due to bush wear. Edited June 18, 2018 by Chris Wilson Typos, senility (see edit history) Quote Link to comment Share on other sites More sharing options...
SupraLEDrears Posted June 18, 2018 Share Posted June 18, 2018 Check the caliper pistons are retracting after a hard brake application with the engine running to give servo assist. If the wheels do not rotate very freely due to brake bind the pistons are noty free enough for the deliberately shaped seal recesses in the caliper bores to retract the pistons from the pads a few thousandths of an inch. this will cause uneven piston pressures on the disc which in turn causes "strange things" to occur. The seal grooves DO NOT have a flat bottom, the bottom of the grooves are chamfered at an angle to deform the seals in brake application and their hysteresis should retract the pistons a tad when the brakes are released. get someone to with the front tyres and wheels within the front arches when you hit the brakes hard at a fast walking pace. if they move back more than a bit in the arches the wishbone bushes are shot, any brake imbalance or slight (and normal...) frictional changes between pads and discs will start an oscillation at certain speeds. Older BMW's were notorious for this due to bush wear. I'll give that a go thanks chris Quote Link to comment Share on other sites More sharing options...
Paul372 Posted June 23, 2018 Author Share Posted June 23, 2018 They seem to be fine at low speeds and normal driving but as soon as they build up a bit of heat they are awful and start getting brake judder Quote Link to comment Share on other sites More sharing options...
bignum Posted June 23, 2018 Share Posted June 23, 2018 Get the discs skimmed on the car using 1 of these,https://brakelathe.co.uk/ if you search on their site it will show garages local to you that can do it, problem with new discs is that once you put a few heat cycles through them the discs harden , i get mine machined after a couple of trackdays then they don`t warp again. Quote Link to comment Share on other sites More sharing options...
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