RangerWill Posted May 18, 2013 Share Posted May 18, 2013 Gentlemen need your help. I have a 77 280z. Stock brakes. Today I changed out my wheel clylinders for the rear and pads in the front. I did pull the calipers so I know I lost my system pressure there. Like the title says I've bled this thing 5 times now. Master first, right rear, left rear, right front, left front. 5 pumps then hold. Open the valve while the pedels down. Close the valve, release the pedel. Issue. The pedel feels great. Lots of pressure from top to bottom. On test drives the back brakes grab and the front doesn't. If I pump while driving the calipers will finally grab. What the hell?!?!?! I know i have new fluid all through the system. Also new MC and booster. Brakes worked fine before I disconnected the calipers and changed the wheel cylinders. Need some help guys. Got a car show in the morning. Haha. Quote Link to comment Share on other sites More sharing options...
RangerWill Posted May 18, 2013 Author Share Posted May 18, 2013 Another thing. While pumping the brake there is a lot of movement in the reservoirs. I can see thw fluid trying to jump out of the reservoirs. Good hard stream of fluid comes out of the bleeder valves though. At a lose. Quote Link to comment Share on other sites More sharing options...
Miles Posted May 18, 2013 Share Posted May 18, 2013 read: http://forums.hybridz.org/topic/109115-master-cylinder-bench-bleeding/?hl=bleeding and Search Quote Link to comment Share on other sites More sharing options...
NewZed Posted May 18, 2013 Share Posted May 18, 2013 I did pull the calipers You might have switched them when you reinstalled. They'll fit either side, but the wrong way puts the bleed bolt at the bottom, leaving the air at the top. Quote Link to comment Share on other sites More sharing options...
Chris Duncan Posted May 18, 2013 Share Posted May 18, 2013 (edited) Brakes worked fine before I disconnected the calipers..... didn't refresh, NewZed beat me to it. Edited May 18, 2013 by Chris Duncan Quote Link to comment Share on other sites More sharing options...
RangerWill Posted May 18, 2013 Author Share Posted May 18, 2013 Checked the calipers. They're fine. I lean towards the MC. I've never fluid try to shoot out the reservoirs. Quote Link to comment Share on other sites More sharing options...
Domzs Posted May 18, 2013 Share Posted May 18, 2013 Checked the calipers. They're fine. I lean towards the MC. I've never fluid try to shoot out the reservoirs. Meaning the bleeders are on top ? On some vehicles , fluid will shoot out the res. while pumping the pedal . Quote Link to comment Share on other sites More sharing options...
RangerWill Posted May 18, 2013 Author Share Posted May 18, 2013 Rgr. Bleeders are on top of the line " in " of the calipers. Theres also a hissing sound while pressing the pedel. Just not understanding how changing cylinders and pads can cause my entire system to fail. Headed to a lift shop. Checking all connections and bleeding again. Quote Link to comment Share on other sites More sharing options...
Domzs Posted May 18, 2013 Share Posted May 18, 2013 Hissing from booster ? Quote Link to comment Share on other sites More sharing options...
RangerWill Posted May 18, 2013 Author Share Posted May 18, 2013 Sounds more like the MC. Quote Link to comment Share on other sites More sharing options...
Domzs Posted May 18, 2013 Share Posted May 18, 2013 Since you replaced MC and booster , might want to check the booster push rod to make sure it's adjusted correctly . I replaced mine recently and rod was too short ( converted 8" to 10" booster ) . It had low pedal ( late engagement ) . Quote Link to comment Share on other sites More sharing options...
RangerWill Posted May 18, 2013 Author Share Posted May 18, 2013 I too went to the 10". But I drove the car for over a month on the current setup with no issues. Could it have come outta adjustment from changing the pads and cylinders? Quote Link to comment Share on other sites More sharing options...
RangerWill Posted May 18, 2013 Author Share Posted May 18, 2013 Which reservoir do you bleed first? Quote Link to comment Share on other sites More sharing options...
Xnke Posted May 18, 2013 Share Posted May 18, 2013 You probably need to reset the brake safety switch. If you only have line pressure on the rears, or only on the fronts, then you've probably tripped it and it's locked off one side or the other. Quote Link to comment Share on other sites More sharing options...
RangerWill Posted May 18, 2013 Author Share Posted May 18, 2013 One the first pedel press it only grabs the back on test drives. If I pump I get pressure in the front and it grabs. Quote Link to comment Share on other sites More sharing options...
RangerWill Posted May 18, 2013 Author Share Posted May 18, 2013 Should the MC be so loud when you press the pedel? I don't ever remember it being that loud. Also never seen the fluid actually trying to spout out of the reservoirs when you press the pedel either. Thoughts on that? Quote Link to comment Share on other sites More sharing options...
NewZed Posted May 18, 2013 Share Posted May 18, 2013 You said the fluid squirts when you press the pedal but it should only squirt when you release it and the fluid returns to the reservoir. The amount that shoots back is the amount that got pushed out in the first place. The large amount implies a big bubble being compressed or something flexible moving and springing back. Watch the reservoir level while the pedal is pushed to see how much is pushed out. Here's another bleeding trick if you're sure everything's right. Read Post #16 here - http://www.classiczcars.com/forums/wheels-tires-brakes-s30/49342-i-am-my-wits-end-these-brakes.html Quote Link to comment Share on other sites More sharing options...
RangerWill Posted May 18, 2013 Author Share Posted May 18, 2013 Tried those, nothing. Same issue. I ordered another MC. Itll be here tmr morning. Will post results. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted May 18, 2013 Share Posted May 18, 2013 Fluid shoots out of my reservoirs if the little strainer basket is not in-that's normal. Make sure you didn't leave them out. Did you bleed the master? Sounds like air in front brakes portion of master. Also, I think the front and back portions of the master cylinder swapped locations at some point in the production years. Make sure that didn't change from you're old MC to your new MC. There should be a F and R stamped on the side of the MCs. Haven't talked about check valves. You want no check valve in the front. You want one in back if drums, none if discs. I bleed the MC by routing a clear tube from the bleeder to the reservoir so it doesn't consume fluid except that volume replacing any air. If you keep the hose under water(fluid), you dont have to open and close the bleeder as your friend pumps. This is still a 2-person job. Bleed the master again if all else looks good. Then go back to each wheel. Purists will disagree, but if this is a daily driver, you can reuse your fluid if it is clean from the multiple bleedings. I hate brakes too. The backs are still drums, right? Subscribed. I feel your pain. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted May 18, 2013 Share Posted May 18, 2013 I also had a problem years ago when I bought my front pads from one company and my shoes from another. The rears had a much higher coefficient of friction and the car wanted to swap ends when the rears locked earlier than the front. But pumping up the pedal wouldn't affect that so that's probably not your problem. Just trying to help. Quote Link to comment Share on other sites More sharing options...
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