Stupid_fast Posted March 19, 2013 Report Share Posted March 19, 2013 These are stock 1972 510 front disc brakes. I thought I'd clean up my brakes and get em to work a bit better because they're rusty and don't work great. I removed the calipers, and disassembled them. I cleaned up the brackets, sanded some rust off of them so they're smooth at the contact points, re-greased them and assembled them. For the cylinders, I took out the bleeders and blasted out the pistons with brake cleaner both ways a few times, some bits of rust and crap came out. I let them sit to dry for about 15 minutes, while I was reassembling the caliper brackets. I installed new pads and bleeder valves and reassembled everything onto the struts. Then I bled the left side until fluid ran clear, then bled right side until fluid ran clear. Ran about 1/4th a liter of fluid through to get it bled. pumped up the pedal and it feels softer now. I took it for a drive downhill, hard on brakes and the rear drums lock up and the fronts are doing barely anything. It stops ... but not very well at all, I drove back around the block to my house. I tried bleeding at the master cylinder, and the fluid ran clear with no bubbles. Then I bled both sides again, the fluid was clear with no bubbles. My bleed method is using a bottle of brake fluid and some tubing that fits snugly over the bleeder. It has worked well in the past with these brakes and bleeding the clutch. It worked slightly better when I bled them again, but a test drive and the rears lock up and the fronts are barely working. Before I did anything the fronts would lock about the same time as the rears if I really got on the brakes. I'm planning to upgrade the brakes to ZX or other option soon, but I just bought new tires and motor upgrades and don't want to break the bank yet if I don't have to. I'm really curious if I've done something wrong. I don't understand why they aren't working after trying to repair them. I've been checking le google but have not found anything useful. Thanks. TL;DR, Changed front pads, cleaned calipers, bled system, rears now grip more than the fronts and soft pedal. Quote Link to comment
q-tip Posted March 19, 2013 Report Share Posted March 19, 2013 The front pads on a stock 510 discs are angled maybe you have them installed wrong? Quote Link to comment
Stupid_fast Posted March 19, 2013 Author Report Share Posted March 19, 2013 The front pads on a stock 510 discs are angled maybe you have them installed wrong? They only go in one way. Each side is angled differently. These are the same pads I ran last time with no issues. Le rage... I don't want to buy new brakes right now. Quote Link to comment
q-tip Posted March 19, 2013 Report Share Posted March 19, 2013 They bled completely Quote Link to comment
Stupid_fast Posted March 19, 2013 Author Report Share Posted March 19, 2013 They bled completely its in my post, yes. I bled about half a liter through the lines. Clear fluid coming out of the tube and no bubbles. Quote Link to comment
q-tip Posted March 19, 2013 Report Share Posted March 19, 2013 Well shit.....calipers could be bad, or the master cylinder. And im out if ideas after that Quote Link to comment
datzenmike Posted March 19, 2013 Report Share Posted March 19, 2013 Any chance you put the right side caliper on the left side? This would put the bleeders too low to get all the air out. Quote Link to comment
Stupid_fast Posted March 19, 2013 Author Report Share Posted March 19, 2013 Any chance you put the right side caliper on the left side? This would put the bleeders too low to get all the air out. Nope, I disassembled them and reassembled one at a time. Also I put new bleeders in the top hole. Glad to know its not only a mystery to me... thanks for the comments. I'm just gonna go with bad calipers. As I said I need new brakes anyway. Quote Link to comment
datzenmike Posted March 19, 2013 Report Share Posted March 19, 2013 Soft usually means trapped air. In a hydraulic situation, liquid does not compress. Can't see it being calipers that did work just a short time ago. Is it safe to drive? Quote Link to comment
Stupid_fast Posted March 19, 2013 Author Report Share Posted March 19, 2013 Soft usually means trapped air. In a hydraulic situation, liquid does not compress. Can't see it being calipers that did work just a short time ago. Is it safe to drive? maybe. I could try pulling out the calipers again and filling them up with fluid manually before reinstalling. But I don't understand .. Its probably something to do with the fact I tried cleaning out the calipers ?? It was some autozone brake cleaner. Got a ton of rust/dirt out of the calipers... I'd expect them to work better. No, the front brakes barely work drastically reducing the effectiveness of the brakes. Last test drive took it up to 40mph, mashed on the brakes and the rears locked and it went a little sideways.(no problem with a little counter steer, of course. Stayed in my lane.) I only drove it around the block near my house. Its not a big problem since its not my daily. but I'm not driving it until they're fixed. Quote Link to comment
datzenmike Posted March 19, 2013 Report Share Posted March 19, 2013 I had a broken bleeder on my Cutlass. Took the caliper off and filled through the hydraulic brake line. Worked hot damn! Getting desperate... try it. If that doesn't fix the proiblem then the master is fucked. The rear piston and seal (front brakes) inside the master gets used to the same travel and may have worn a groove. When bleeding the peddle travels further pushing the piston further into the master. Maybe this chewed up the seal??? You said you bled the master? It was the rear bleeder right? for the fronts. Quote Link to comment
Stupid_fast Posted March 19, 2013 Author Report Share Posted March 19, 2013 I had a broken bleeder on my Cutlass. Took the caliper off and filled through the hydraulic brake line. Worked hot damn! Getting desperate... try it. If that doesn't fix the proiblem then the master is fucked. The rear piston and seal (front brakes) inside the master gets used to the same travel and may have worn a groove. When bleeding the peddle travels further pushing the piston further into the master. Maybe this chewed up the seal??? You said you bled the master? It was the rear bleeder right? for the fronts. The bleeders are new, and fluid is coming out of them. Bubbles came out when I initially opened them up. Lots of fluid came through the system. Yup the rear bleeder. Didn't touch the drum system as they've been working well. Was going to replace the master at the same time as front brake upgrade ... 280z master to replace stock 510 one. If the master had died, would the rear brakes still work perfectly ??!?!! Friend was telling me about some brembos still have to call the source he mentioned for information. I still don't see the point in getting anything better than ZX fronts ... Even if I had a heavier motor. But worth to check the asking price of that setup. Car has so much grip and so little power that I barely even use the 510 brakes through a mountain road. Quote Link to comment
datzenmike Posted March 19, 2013 Report Share Posted March 19, 2013 Yeah the rears are separate from the fronts. If going ZX struts and brakes get the matching 15/16" zx master. I put Maxima goon struts on and it 's based on the ZX platform too. It had a 15/16" master and I love the brakes!!!! A larger caliper needs a matching larger master to keep the effort the same. A smaller master on a larger caliper will be easier to step on but the rod will travel further and feel mushy. A larger master on a small caliper will feel stiff and have less travel. Quote Link to comment
Guest 510kamikazifreak Posted March 19, 2013 Report Share Posted March 19, 2013 Yeah the rears are separate from the fronts. If going ZX struts and brakes get the matching 15/16" zx master. I put Maxima goon struts on and it 's based on the ZX platform too. It had a 15/16" master and I love the brakes!!!! A larger caliper needs a matching larger master to keep the effort the same. A smaller master on a larger caliper will be easier to step on but the rod will travel further and feel mushy. A larger master on a small caliper will feel stiff and have less travel. Keep in mind,710's have a brake booster. The 7/8 is the most common for the zx swap(to lose the overstiff pedal)in a 510 without brake booster Or could put in a b-210 booster(easy install) OP... Also what pads did you use? There are many different ones out there,soft etc did you do a few good heat ups, To Seat the pads? Quote Link to comment
Stupid_fast Posted March 20, 2013 Author Report Share Posted March 20, 2013 Yeah the rears are separate from the fronts. If going ZX struts and brakes get the matching 15/16" zx master. I put Maxima goon struts on and it 's based on the ZX platform too. It had a 15/16" master and I love the brakes!!!! A larger caliper needs a matching larger master to keep the effort the same. A smaller master on a larger caliper will be easier to step on but the rod will travel further and feel mushy. A larger master on a small caliper will feel stiff and have less travel. I've always been under the impression the 280ZX 15/16ths master was too radical for rear drum brakes. And that the 280z (big front disc + rear drum) was the desirable setup. So ZX master ??? Keep in mind,710's have a brake booster.The 7/8 is the most common for the zx swap(to lose the overstiff pedal)in a 510 without brake booster Or could put in a b-210 booster(easy install) OP... Also what pads did you use? There are many different ones out there,soft etc did you do a few good heat ups, To Seat the pads? Bendix maybe? They are the same pads I ran last time. I bought them at the same time, they worked perfectly last time! I didn't have to wear them in last time, why would I have to wear them in this time ??? plus soft pedal feel. I prefer a firm pedal with good feedback. Quote Link to comment
Stupid_fast Posted March 20, 2013 Author Report Share Posted March 20, 2013 did you do a few good heat ups, To Seat the pads? THE REWARD IS MORE CHEEEZE. Just drove about on a flat road in 3rd gear holding the brake for about a minute, then tested em out a few times. Definitely better, fronts actually got to lock up once! Looks like they do need to wear in. Them more you know ... Thanks guys. These should last a month or two to save for a good brake setup. Quote Link to comment
Guest 510kamikazifreak Posted March 20, 2013 Report Share Posted March 20, 2013 THE REWARD IS MORE CHEEEZE. Just drove about on a flat road in 3rd gear holding the brake for about a minute, then tested em out a few times. Definitely better, fronts actually got to lock up once! Looks like they do need to wear in. Them more you know ... Thanks guys. These should last a month or two to save for a good brake setup. :thumbup: The rotors may be glazed (just a fyi) Quote Link to comment
datzenmike Posted March 20, 2013 Report Share Posted March 20, 2013 The pads will be riding on the high points on the rotor (even if you sanded them) If you get them hot be sure not to stop for any length of time until they cool down. New pad material can transfer to the hot metal rotor and leave a 'muddy footprint'. After this the pads will grip the pad material on the rotor and the peddle my pulse slightly when braking. A few weeks and the pads 'age' and this is less likely. The rotors may be glazed (just a fyi) I think he said he sanded them. Quote Link to comment
Guest 510kamikazifreak Posted March 20, 2013 Report Share Posted March 20, 2013 I think he said he sanded them. Not sure if I read that or no, I blame it on Craft disease C..ant R..emember A F..ucking T..hing :lol: Sanding I dont think will do enough if glazed Quote Link to comment
datzenmike Posted March 20, 2013 Report Share Posted March 20, 2013 I use a small block of wood with sand paper wrapped around it. Machining would be best but this is slightly better than just using your hand. Circular motion. Quote Link to comment
Guest 510kamikazifreak Posted March 20, 2013 Report Share Posted March 20, 2013 Yes that is better than nothing for sure :thumbup: a quick rotor turn is best Quote Link to comment
datzenmike Posted March 20, 2013 Report Share Posted March 20, 2013 Yes but the last time I did that they wanted $18!!! New ones were $20.(Dodge Omni) Quote Link to comment
Stupid_fast Posted March 20, 2013 Author Report Share Posted March 20, 2013 I did not sand the rotors, I sanded the caliper brackets where they slide against eachother. (self-adjusting to the slanted pads) The rotors were turned like 10k miles ago ... I have not seen a reason to do it again ? The sky decided to rain tonight, when I ran earlier it was only sprinkling luckily but I'd rather not go for another run tonight. Next time its dry I'll throw it through a pass and see if I can wear them in good. Thanks for the help guys. Quote Link to comment
Guest 510kamikazifreak Posted March 20, 2013 Report Share Posted March 20, 2013 Yes but the last time I did that they wanted $18!!! New ones were $20.(Dodge Omni) I know shit is getting out of hand.. When new is just as cheap Quote Link to comment
Guest 510kamikazifreak Posted March 20, 2013 Report Share Posted March 20, 2013 The rotors were turned like 10k miles ago ... I have not seen a reason to do it again ? Most likely not,Unless they have been subdued to alot of heavy braking,with alot of heat cycles(ie track days) Quote Link to comment
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