Daphur280 Posted September 23, 2013 Share Posted September 23, 2013 So nearing the point of getting my Z back on the road and I am having severe brake bleeding issues. Its a 73 240z w/ Toyota S12+ (non vented), '85ish Maxima rear brakes with DatsunPartsLLC brackets, and 15/16 Master Cylinder, and braided lines front and rear. Calipers and master cylinder were good prior to install. In a hurry (because I was moving) I put the master cylinder, bled the system and actually had pressure throughout the system, it was loaded onto a flatbed and towed to where I'm at now. I finished installing the e-brake, ran the car and I have squishy pedal, no pressure or brakes until I pump the brake pedal 3 times. I pulled the Z back in the garage and noticed upon the 3rd or 4th brake pedal pump and on it would "hiss" at the last inch of pushing the pedal. I bench bled the MC, re-bled the system, and still the same story, no pressure until I pump the brakes in rapid sequence and on the 3rd or 4th press. Also I'm noticing when I bleed the rear brakes I'm barely getting any fluid coming out, or at least no where as near as much as I do in the front. I have no signs of leaking anywhere (lines, brakes, distribution blocks, MC, booster), and I am at a loss. I'm considering taking it to a brake shop and have them bleed it with a brake flusher (so it bleeds all 4 corners at the same time). But I'm on a budget and would rather save the $$. Any ideas? Quote Link to comment Share on other sites More sharing options...
NewZed Posted September 23, 2013 Share Posted September 23, 2013 Check bleed valve orientation. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted September 23, 2013 Share Posted September 23, 2013 So you just installed the master? Reaction disk or master pushrod adjustment are my guesses if that's the case. Quote Link to comment Share on other sites More sharing options...
Daphur280 Posted September 23, 2013 Author Share Posted September 23, 2013 Check bleed valve orientation. as in how tight/deep are the bleeder valves? So you just installed the master? Reaction disk or master pushrod adjustment are my guesses if that's the case. Its been installed before moving, and I had pressure, then I bled the system, test drove, bench bled the master, then bled the system, then test drove again. Quote Link to comment Share on other sites More sharing options...
NewZed Posted September 24, 2013 Share Posted September 24, 2013 as in how tight/deep are the bleeder valves? Some of the popular brake swaps end up with the bleed bolt at a position other than the very top, where the air is. The bleeder needs to be where the air is, otherwise fluid flows past but doesn't take the air with it. You might have to remove a caliper mounting bolt to rotate the bleeder to the top for bleeding then put it back for use. Just something to check, I'm not familiar with the details of your swap. Quote Link to comment Share on other sites More sharing options...
Naptown Dave Posted September 24, 2013 Share Posted September 24, 2013 I have a similar setup except I have a 1" Wilwood master. I have bled the hell out of the lines. Vacuum bled, gravity bled, set up a recirculating line back to my M/C with a check valve at the bleeder and finally last night set up a pressure bleeder using a garden sprayer, clear hose and an old M/C cap. I have 7 one quart bottles of fluid in my garage and at least one of them has been emptied on the floor for various reasons! It looks like the fronts are firm but in the back the master starts to empty as I pump the pedal and then fills back up slowly after pumping, to me that means I still have air trapped in the back lines. I am going to pressure bleed the backs again, after getting the 8th bottle of fluid (2 gallons total!). I think I will try to pressurize the system and open both bleeders at once to see if I can flow any more air out. I did check the reaction disc and blocked off the outlets to the M/C to make sure it's not leaking through, it builds pressure instantly and doesn't fall off. I'm not 100% sure my M/C push rod is set correctly but if anything it is set a little short so I would think that if all the lines are free of air I would have a solid pedal, just a little lower than expected. I have about 30 hrs into trying to get my brakes working and I am getting more than a little frustrated. I think I have tried everything that I have seen on the interweb, does anyone have any suggestions if the pressure bleed doesn't work tonight? Quote Link to comment Share on other sites More sharing options...
Miles Posted September 24, 2013 Share Posted September 24, 2013 (edited) With Maxima and 240SX calipers I found that I had to unbolt the caliper from the bracket and bleed it while shaking, tapping and moving the caliper in various orientations to get the air out. Unless you have a pressure bleeder you have to block the piston with something so it doesn't push out. I use a caliper piston tool (Harber Freight $30) turned all the way in to hold the piston while pumping the pedal. Use Earls Solo Speed Bleeders or other brands of bleeders that have a check valve built into them on the calipers and master cylinder. Edited September 24, 2013 by Miles Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted September 24, 2013 Share Posted September 24, 2013 Once you get good clear fluid coming out of the bleed screw, I wouldn't judge you for re-using the fluid and pouring it back in the reservoir. I think we have all been there. Quote Link to comment Share on other sites More sharing options...
Miles Posted September 24, 2013 Share Posted September 24, 2013 Bleeding a Z can be very frustrating judging by the number of threads dealing with that subject. If all else fails, fill a swimming pool with brake fluid and immurse your car in it for a few days! Quote Link to comment Share on other sites More sharing options...
socorob Posted September 24, 2013 Share Posted September 24, 2013 I had some GM calipers with parking brakes on a different car that I had to remove from the brackets and turn all around while tapping with a rubber mallet to get the air out of them. This was gravity bleeding with a clear tube going into a bottle of fluid. It was ridiculous how moving it all around and tapping, shaking and everything else then the tiniest bubble would come out. They sucked so badly but for some reason all the hot rod guys love them. Quote Link to comment Share on other sites More sharing options...
Naptown Dave Posted September 25, 2013 Share Posted September 25, 2013 That swimming pool idea is sounding better! After running the first gallon thru I started recycling it! I figure I've flushed any crap out of the lines by now and will probably run a new bottle through if I ever get any pedal on this thing. Quote Link to comment Share on other sites More sharing options...
Miles Posted September 25, 2013 Share Posted September 25, 2013 Too many people never follow up with a solution. Be sure to post your solution(s) once you are able to get a firm pedal. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted September 25, 2013 Share Posted September 25, 2013 Amen, Miles. Dave, it is super easy to swap out fluid once the air is out. If I have a super higher temp experience, I swap from one color fluid to another and it only takes a second to know that I'm flushed. I did have a line-lock solenoid o-ring failure recently and I'm wondering if one fluid or another made it brittle(?). I got speed bleeders last year and I can't say enough about them. Quote Link to comment Share on other sites More sharing options...
Naptown Dave Posted September 25, 2013 Share Posted September 25, 2013 (edited) Well the pressure bleed with removing the calipers and rotating and tapping did the trick.I pulled the calipers while gravity bleeding and it didn't help. It seems like there may be a little room for improvement but the pedal doesn't hit the floor with the engine running. A few more good hours and I'll be terrorizing the neighborhood! Edited September 25, 2013 by Naptown Dave Quote Link to comment Share on other sites More sharing options...
Daphur280 Posted September 27, 2013 Author Share Posted September 27, 2013 Some of the popular brake swaps end up with the bleed bolt at a position other than the very top, where the air is. The bleeder needs to be where the air is, otherwise fluid flows past but doesn't take the air with it. You might have to remove a caliper mounting bolt to rotate the bleeder to the top for bleeding then put it back for use. Just something to check, I'm not familiar with the details of your swap. Everything is oriented correctly, I made this mistake the first time I put on my Toyota calipers Too many people never follow up with a solution. Be sure to post your solution(s) once you are able to get a firm pedal. I'm gonna rebelled everything twice over and let you know Quote Link to comment Share on other sites More sharing options...
Domzs Posted September 27, 2013 Share Posted September 27, 2013 I would check the master to make sure it didn't go bad . You can remove the brake lines then plug the holes ( at master ) , press the pedal ( slowly ) down to see if it's firm and holds pressure . You could have a master that's bleeding through . Quote Link to comment Share on other sites More sharing options...
Daphur280 Posted September 30, 2013 Author Share Posted September 30, 2013 I would check the master to make sure it didn't go bad . You can remove the brake lines then plug the holes ( at master ) , press the pedal ( slowly ) down to see if it's firm and holds pressure . You could have a master that's bleeding through . As in bleeding through into the booster? If its not bleeding through it (the pedal) shouldn't move at all right? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted September 30, 2013 Share Posted September 30, 2013 It's possible for the front and rear to leak to each other. If you have this situation and pump the pedal a lot you'll see the front master reservoir filling up and the rear going empty. It could also pump fluid into the booster. Quote Link to comment Share on other sites More sharing options...
Naptown Dave Posted October 3, 2013 Share Posted October 3, 2013 Daphur, sorry to threadjack earlier! Have you made any progress? One thing I noticed that helped me isolate my problem (air in the caliper) was my fluid level dropping in my rear master as I pumped the brake and then slowly returning as the trapped air pushed the fluid back ti the m/c. Like I said above I ended up using a homemade pressure bleeder and removing the calipers from thethe mounts so I could get all the air out of them. Basically turning them so the bleed screw was at the highest point. If you don't have much flow to th back that may make getting a good bleed tough. There have been some posts about the safety switch on the drivers side inner fender going bad and not allowing fluid flow to both the front and back, you may want to look into that as well. I'm no expert but do have some recent experience! Quote Link to comment Share on other sites More sharing options...
Daphur280 Posted October 8, 2013 Author Share Posted October 8, 2013 (edited) No progress, I let the pressure bleeder go to town on the calipers and I still have to pump up 3-4x to get pressure. Could this braided line orientation be causing some issues? With the way the line is above the bleeder? Edited October 8, 2013 by Daphur280 Quote Link to comment Share on other sites More sharing options...
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