bayside_supra Posted June 19, 2017 Share Posted June 19, 2017 Hi guys I have 2 issues that no mechanics can seem to fix on my car, I've spent a fair amount of money so far and have no improvement on either issue so I'm hoping you can help. First is spongy brakes. The pedal has always been soft since I bought the car, you sort of lose half the pedal before they bite. They do stop the car fine, just pedal feels rubbish. I have uk brakes with brand new oem discs, CW pads, Goodridge braided lines. So far I have tried the new discs and pads, new fluid, recently a brand new master cylinder (really pricey). Nothing has worked! What else is there to do? Next is no a/c, no joke in this weather lol. The air con does not kick in at all. The diagnostic test flashes with abnormal pressure. So far I have replaced the air con rad, the air con pump, had it regassed and there is no leaks. All fuses are ok, not sure what to do? Any help would be hugely appreciated. Cheers Karl Quote Link to comment Share on other sites More sharing options...
mwilkinson Posted June 19, 2017 Share Posted June 19, 2017 Aircon could be the expansion valve. My first supra had this problem. With regards to the brakes I wonder if this is just a perception thing. Have you tried a different supra with UK spec brakes to get a frame of reference? Quote Link to comment Share on other sites More sharing options...
Mike2JZ Posted June 19, 2017 Share Posted June 19, 2017 Does your supra have ABS ? Quote Link to comment Share on other sites More sharing options...
Sheefa Posted June 20, 2017 Share Posted June 20, 2017 UK brakes are spongy compared to big brake kits or modern cars I'm afraid. You could try a master cylinder stopper which may help a little but unfortunately it's unlikely you'll get the firm pedal pressure you're after. Quote Link to comment Share on other sites More sharing options...
Burna Posted June 20, 2017 Share Posted June 20, 2017 UK brakes are spongy compared to big brake kits or modern cars I'm afraid. You could try a master cylinder stopper which may help a little but unfortunately it's unlikely you'll get the firm pedal pressure you're after. /QUOTE] Yep, as Sheefa says, that's just the way they feel. I fitted a master cylinder stopper years ago and didn't notice any difference really. Over the years the best brake parts combination I've found for the UK brake setup is: Goodridge braided brake lines Motul RBF 600 brake fluid Porterfield R4 Race Compound brake pads You will still have the spongy feel, and because they are race pads you will have less braking from cold, but once some heat is in them and you need to go for the peddle hard, jesus they do stop! Quote Link to comment Share on other sites More sharing options...
Dave Carroll Posted June 20, 2017 Share Posted June 20, 2017 As far as UK brakes go, mine are very hard as far as feel goes. And this is with standard rubber lines. They are hard regardless of which pads I have in (my CW race endurance pads or endless street/track pads). The biggest difference I felt was when I switched the fluid to Castrol React SRF. Must be changed once per year and is pricey but best fluid I have ever come across. Quote Link to comment Share on other sites More sharing options...
Dnk Posted June 20, 2017 Share Posted June 20, 2017 (edited) Never had a spongy pedal in either of my UK specs Bleed my brakes with a hand pump vacuum bleeder and get a very good pedal http://www.mkivsupra.net/vbb/content.php?57-Brake-System Edited June 20, 2017 by Dnk (see edit history) Quote Link to comment Share on other sites More sharing options...
SupraLEDrears Posted June 20, 2017 Share Posted June 20, 2017 Brakes servo ok? I had a spongy feel on my ls400 fronts after bleeding with the vac line bottle method. Turned out that I pumped the pedal way too hard and it kept sucking air from the bleeder nipple. I just gave it two slow pumps and let gravity pull the fluid through. nipped it up and now they're quite firm. Quote Link to comment Share on other sites More sharing options...
Dnk Posted June 20, 2017 Share Posted June 20, 2017 Brakes servo ok? I had a spongy feel on my ls400 fronts after bleeding with the vac line bottle method. Turned out that I pumped the pedal way too hard and it kept sucking air from the bleeder nipple. I just gave it two slow pumps and let gravity pull the fluid through. nipped it up and now they're quite firm. Pumping the pedal ? Quote Link to comment Share on other sites More sharing options...
evinX Posted June 20, 2017 Share Posted June 20, 2017 Check the connection on the heater control board. They can burn out. Or wire in a temp switch to activate the pump. Whst fluid you got? I got uks and i dont loose half the travel before engagement. I used motul rbf600 Quote Link to comment Share on other sites More sharing options...
SupraLEDrears Posted June 20, 2017 Share Posted June 20, 2017 Pumping the pedal ? I know you only need gravity but I pumped the pedal just to get it going. Quote Link to comment Share on other sites More sharing options...
Dnk Posted June 20, 2017 Share Posted June 20, 2017 The vacuum draws the fluid through, not gravity or pumping the pedal Quote Link to comment Share on other sites More sharing options...
bayside_supra Posted June 20, 2017 Author Share Posted June 20, 2017 Thanks for all the replies. Yes the car has abs. Darren at Whifbitz concurred that my brakes don't feel how they should. I think I will try another servo but hopefully I can borrow one from them before I fork out for it. I got a pm from David P saying to try removing the anti squeal shims, has anyone had success trying this? I will see if the expansion valve is at fault for the air con. What do you mean by wire in a temp switch evinX? Quote Link to comment Share on other sites More sharing options...
rider Posted June 20, 2017 Share Posted June 20, 2017 (edited) With your a/c I'd look to a lack of power or failure of your pressure sensor/switch 88645-20050. eBay USA has claimed compatible switches for $6 or £230 from Toyota. Edited June 20, 2017 by rider (see edit history) Quote Link to comment Share on other sites More sharing options...
evinX Posted June 21, 2017 Share Posted June 21, 2017 Well originally the contacts on the heater control boards burnt out and the ac button didnt work. The previous owner wired a 2 point switch with one wire going to the fusebox's ac fuse and the other end earthed that used to get my pump working. But my dad opened up the heater unit, found burnt contacts and bridged them with wire. Possibly why yours isnt kicking in? Quote Link to comment Share on other sites More sharing options...
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