MKIV-Supra Posted July 29, 2018 Share Posted July 29, 2018 Hey Guys, sorry for my bad english, i try my best to explain my problems. Since i have the car, i never tried if the ABS works or not. On my last Ride i had to brake hard and i found out, my ABS doesn't work. The rear tyres blocked when i braked hard, so i had to open the brake and catched the Supra. Now i wanted to find out where my Problem is. The ABS Actuator works. Trouble Codes are non there. Then i took the Supra to a big greenfield and tried again to brake hard. On the grass the ABS does work, you can feel it in the pedal too, and the tyres dont block. Then i tried it on a dirt track too, and here are the rear tyres blocking, most the rear right tyre, ABS didnt want to work here anymore. After that i took the Supra on the road again and tried it there too. 4 Hard brakes and always the Rear Right Tyre was blocking first and then the left came too. In the Front are NEW 4 Pot Calipers with OEM Discs and Hawk Pads. On the Rear i have the J-Spec calipers. These have also new Discs and Pads, Pistons aren't sized or anything. I've measured everything out, ABS Sensor had 1,01kOhm in the Front and 0,95kOhm in the back @28°C. Relays are also working and everything is good. Do you have some tips for me, where i should start to search now? Thanks and i hope you can understand what i wrote Quote Link to comment Share on other sites More sharing options...
mellonman Posted July 29, 2018 Share Posted July 29, 2018 Have you actually checked the resistance across the abs relay contact? Have you checked the abs fuse? Quote Link to comment Share on other sites More sharing options...
MKIV-Supra Posted July 29, 2018 Author Share Posted July 29, 2018 Hi, Yes ive checked everything. I have to rebuild the rear right caliper and then look forward, hope my fault is the brake caliper. It isnt completely sized, but it moves harder then the left side. Quote Link to comment Share on other sites More sharing options...
Ric Posted July 29, 2018 Share Posted July 29, 2018 If the abs light goes out after turning on the ignition then everything should be fine? Quote Link to comment Share on other sites More sharing options...
Dnk Posted July 30, 2018 Share Posted July 30, 2018 I'd look closely at both rear calipers and either rebuild them or replace them Quote Link to comment Share on other sites More sharing options...
Scooter Posted July 30, 2018 Share Posted July 30, 2018 The rear pads are hawk too or just standard ones? Is the car prefacelift or facelift? Chris Wilson always used to not like the Uk front J spec rear setup re braking effort so wondering if 2 pots rears would help? Quote Link to comment Share on other sites More sharing options...
MKIV-Supra Posted July 31, 2018 Author Share Posted July 31, 2018 If the abs light goes out after turning on the ignition then everything should be fine? Yes ABS light goes out. I'd look closely at both rear calipers and either rebuild them or replace them Yes this is my next Step, have to look but i think the right rear one is seized. The rear pads are hawk too or just standard ones? Is the car prefacelift or facelift? Chris Wilson always used to not like the Uk front J spec rear setup re braking effort so wondering if 2 pots rears would help? Car is Prefacelift, rear Pads are oem. 2 Pot will come but first i wanted to Drive it this way. Quote Link to comment Share on other sites More sharing options...
Dnk Posted July 31, 2018 Share Posted July 31, 2018 (edited) I'd definitely be fitting a new pair of UK rears to it to be honest Last time i priced them up with best discount i could get they came in at £283 inc VAT each I have a UK chassis number and reg number i can send to you if you need them to order Edited July 31, 2018 by Dnk (see edit history) Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted August 2, 2018 Share Posted August 2, 2018 At the very least you should run the same compound pads front and rear, if the stock pads have more bite than the hawks on the front this may cause the problem. But the ABS **SHOULD** stop the rears locking up. You can self diagnose the ABS using the dash lights. I would self test the ABS, free the calipoers and sliders on the rewar and fit the same compound pads all round and go from there. Quote Link to comment Share on other sites More sharing options...
MKIV-Supra Posted August 8, 2018 Author Share Posted August 8, 2018 Hi, Diagnostic says no fault. In the dirt it works. Rear calipers are both now refurbished with new oem pistons and new oem sealings. On the street the rear right tyre blocks. Maybe the master cylindre, Not enough pressure for the Front? Quote Link to comment Share on other sites More sharing options...
MKIV-Supra Posted August 21, 2018 Author Share Posted August 21, 2018 Hey Guys, Havent found the fault yet. I had installed the old 2 pot calipers with Same discs and pads as rear. Bleed it several times with foot, under and over pressure. Bleed it with abs and Car on, Same problem as with the 4 pot calipers, now i changed back again and Same again. Should i change the Master cylinder? I‘ve ordered already original oem overhaul Kit from UAE, thats my last idea what i have. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted August 21, 2018 Share Posted August 21, 2018 Is there any danger that the pipes to the master cylinder are swapped over? Or from the ABS unit to the calipers? Are the tyres all the same make and model and of sensible sizes? Quote Link to comment Share on other sites More sharing options...
MKIV-Supra Posted August 21, 2018 Author Share Posted August 21, 2018 Dont think so but maybe some pictures would be good that i can check Mine. Cant find anything about that how the lines are wired. Tyres were changed already, 235/40/18 and 265/35/18. Profiles are Front and rear 3 and 4mm. Old tyres had 2 and 6mm but were old, Rears are now from 2016 and Front 2015. Hankook in Front and uniroyal at back. Quote Link to comment Share on other sites More sharing options...
MKIV-Supra Posted August 21, 2018 Author Share Posted August 21, 2018 Gesendet von iPhone mit Tapatalk Pro Quote Link to comment Share on other sites More sharing options...
MKIV-Supra Posted August 21, 2018 Author Share Posted August 21, 2018 Gesendet von iPhone mit Tapatalk Pro Quote Link to comment Share on other sites More sharing options...
MKIV-Supra Posted August 23, 2018 Author Share Posted August 23, 2018 Okey fault is found. The Left and middle line ob the abs pump was mistaken by the previous owner, have changed it and everything works now! Thanks guys! Gesendet von iPhone mit Tapatalk Pro Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted August 23, 2018 Share Posted August 23, 2018 I should be a mechanic, and give up the film director work, especially after what's happened to poor old Harvey... Quote Link to comment Share on other sites More sharing options...
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