sco_aus Posted September 5, 2011 Posted September 5, 2011 So not too long ago I installed the 4 pot Willwood setup from AZC. It all went on easily, but now, the pads are scraping on the disks and the pistons have not retracted fully when my foot is off the brake. I don't anything about how the brake fluid block jobbies in the engine bay work, could that be the problem? It was suggested that by driving the car, they may retract, but alas, that did not work and just made me nervous lol. Has anyone got any ideas whats going on? Has this happened to anyone else? Cheers Scott Quote
Enzo Posted September 5, 2011 Posted September 5, 2011 Hi, What master cylinder did you use. David Quote
dat2kman Posted September 5, 2011 Posted September 5, 2011 the piston seals in the calipers should be a square section, as you press brake pedal, the fluid pushes piston, and the seal sort of grips and folds out, when you take foot off pedal the sort of folded out square edge of the seal sort of oulls the piston back. In a perfect world!! Sometimes lack of use may cause the seals to not fold forwards and backwars, thus causing the pistons to not rtract, hence pads rubbing. I suffer from too much flexing, and pad knock off, ie the discs wobble/bend and push pads back, so much so, that I have to hit the pedal to get height, then hit the pedal again to brake for a corner ( racing car) the guys following me dont know what the heck i am doing, seeing lights flashing on and off, etc, it causes them a deal of confusion , too bad! Quote
sco_aus Posted September 5, 2011 Author Posted September 5, 2011 Sorry, valid point... I am using the 1" JB1917 or whatever. Thanks mate, so it just needs to wear in a bit? I am just a bit concerned about driving it to wear them in when I can barely even push the car, I think they will be wearing the disks in lol. Quote
peter mc Posted September 5, 2011 Posted September 5, 2011 try bleed them and pump the pedal lots and use .4 fluid not synthetic Quote
sco_aus Posted September 5, 2011 Author Posted September 5, 2011 I used Penrite, but I don't know if it was synthetic. I'll check it out thanks. Quote
Enzo Posted September 5, 2011 Posted September 5, 2011 Hello, I have the same master cylinder on mine. Did you remove the residual pressure valve from the disc brake circuit. The JB1419 was originally made for front and rear drum brakes and has a residual pressure valve fitted to both circuits to keep a small amount of pressure in the lines for drum brakes. They are fitted under the large nuts where the fluid lines connect. For a disc brake front the valve in this line has to be removed or the residual pressure will keep the pads in contact with the rotor causing tight brakes and overheating. If using rear discs as well with this master cylinder both valves should be removed. David. Quote
sco_aus Posted September 6, 2011 Author Posted September 6, 2011 Wow ok, I thought all that jazz was located in the splitter block in the engine bay (admittedly I never thought of removing it anyway...). Thanks mate, I'll get to it. Quote
sco_aus Posted October 18, 2011 Author Posted October 18, 2011 Ok, so I have discovered the problem and it's not what I thought it was at all. Basically the end of the lower control arm (LCA) is grinding on the rotor. I am also running roll centre adjusters from Techno Toy Tuning which I think made it worse. After contacting Dave about it (and having a go at me for not reading the instructions properly lol), I now have a lot of work ahead of me to fix this. First I will have to remove the calipers and hubs, then grind the end of the LCAs down, being sure I don't make the LCA too weak, but give enough clearance. Ill also have to remove the rotors from the hubs and have them machined to get rid of the grooves created by the LCA. I am pissed at myself for letting this happen, I think I assumed that there would be clearance. Quote
tir33d Posted October 28, 2011 Posted October 28, 2011 WOW. Promise I am not being a smartarse. So a "big" kit doesn't just bolt on. I would have thought this kit to be right. It sounds as though the disk needed more offset and the bracket made to suit. Were they designed to fit behind a standard wheel or something? I adapted some 6 pot VTTR's and we had to make bracket and bits and machine rotors down etc. Was worth the effort. Quote
C.A.R. Posted October 28, 2011 Posted October 28, 2011 HOW did you not notice this while you were working on the car?! You're a fair dinkum Gumboot somtimes mate... Ok, so I have discovered the problem and it's not what I thought it was at all. Basically the end of the lower control arm (LCA) is grinding on the rotor. I am also running roll centre adjusters from Techno Toy Tuning which I think made it worse. After contacting Dave about it (and having a go at me for not reading the instructions properly lol), I now have a lot of work ahead of me to fix this. First I will have to remove the calipers and hubs, then grind the end of the LCAs down, being sure I don't make the LCA too weak, but give enough clearance. Ill also have to remove the rotors from the hubs and have them machined to get rid of the grooves created by the LCA. I am pissed at myself for letting this happen, I think I assumed that there would be clearance. Quote
sco_aus Posted October 29, 2011 Author Posted October 29, 2011 HOW did you not notice this while you were working on the car?! You're a fair dinkum Gumboot somtimes mate... Because it wasn't grinding, just scraping, it sounded a lot like brake pads. I've done most of the grinding needed now, just have to finish it and get the rotors machined. Quote
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