philiow313 Posted January 31, 2004 Share Posted January 31, 2004 working on installing new pads, rotors, and SS lines. went to bleed, air kept coming out for awhile and then with constant pedal pressure it would go all the way to the floor everytime. the fluid level in the MC wouldn't drop (this is with all bleeder screws CLOSED). is my MC bad? 1980 280ZX Quote Link to comment Share on other sites More sharing options...
waynekarnes Posted January 31, 2004 Share Posted January 31, 2004 if you replaced all the lines, i would think that you still have air in the lines. if you replaced lines at the master, you will need to bleed the master. take clear hoses put them around the bleeder screws on the master, the other ends back into the master, into the fluid. pump up the master, hold the pedal down ( not too much pressure as the fluid will spray , or blow the hose off ). have some one crack the bleeder screw on the master, pedal goes down. tighten bleeder. pump again, hold pedal down, crack the bleeder, repeat bleeding one side of the master, until no more bubbles. do the same with the the other side ( the other bleeder ). are you bleeding by yourself or with help ? don't mean to insult .. no idea how much experience you have. at the bleeder, use a clear hose, into a bottle, pump brake pedal several times, hold pedal down to the floor, have friend slowly crack the bleeder, pedal should go all the way to the floor. hold the pedal down, friend tightens bleeder, repeat until no air. move to driver's rear, do the same, then the pass front, last the driver's side. i had to use a little over a quart to get all the air out of mine. also, check to be sure, none of the wheel cylinders are leaking. now, if you have a newer z with ABS, you may have to remove the fuse for the ABS, to disable it, before you can bleed the brakes ... check a manual or on line for that info. if you have checked all the wheels, no leaky cylinders or pistons at the calipers, the pistons move smoothly, seals,pistons and such, weren't damaged when pressing em back into place to clear the new pads, then ... take a look at that master. i seriously doubt that the master is bad, if it was fine before. good luck, wayne Quote Link to comment Share on other sites More sharing options...
Synlubes Posted January 31, 2004 Share Posted January 31, 2004 Try bleeding the 2 ports on the master cly first. Then, follow the lines from the master cly, go to which ever line is the farthest away from the master cly (should be 1 of the rears) and start bleeding air until you get good fluid coming out. Then go to the other side and repeat process. Repeat the same process for the fronts (starting with the line farthest from master cly). Once you get good fluid at all 4, I go around again and do a "good bleed". If this does not give you a good firm pedal, somethings sucking air. Pull the rear drums and see if the rear wheel clys are wet (around the seals) if they are ok, master cly. Quote Link to comment Share on other sites More sharing options...
Guest Drewz Posted February 1, 2004 Share Posted February 1, 2004 When I do a job that big I always put at least 2-3 liters of fluid through the system. There are many other things that could cause that as well. Double check all connections first. Quote Link to comment Share on other sites More sharing options...
philiow313 Posted February 2, 2004 Author Share Posted February 2, 2004 we replaced the master cylinder with a brand new one and it built up pressure with the engine off. but when driving the pedal goes down almost to the floor before it starts to work. any ideas what it may be now? we bled the new MC, all four calipers, and its brand new dot 3 fluid. goodridge ss lines up front. axxis pads front and rear, brand new rotors. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted February 2, 2004 Share Posted February 2, 2004 There's a spacer thingy in the booster that sounds like it fell out when you replaced the master. I haven't seen this thing myself, but I've seen several threads that match your description to a T, and this thing was the culprit. If I understand it correctly, the spacer takes up the distance from the pin on the pedal and the back of the master, and is actually inside the booster. Hopefully someone else who has run into this problem will see this post and give you a better description of what I'm talking about. Jon Quote Link to comment Share on other sites More sharing options...
JMortensen Posted February 2, 2004 Share Posted February 2, 2004 I think this piece can fall out of place and down inside the booster. Should have mentioned that before... Jon Quote Link to comment Share on other sites More sharing options...
philiow313 Posted February 3, 2004 Author Share Posted February 3, 2004 hmmm. if i dont get anymore responses ill pull the MC again and find out. Quote Link to comment Share on other sites More sharing options...
zxgts-4 Posted February 3, 2004 Share Posted February 3, 2004 As a mechanic I have to disagree with D Carrow. I have always bled the shortest line first to get the maximum amount of air out of lines using the least amount of fluid 1lt of fluid should easily cover a full flush which you should do every 2 years to remove moisture and prevent corrosion. Yes start with M/cyl working back check for bleed srews in bias valves and any load sensing device. Remember air bubbles rise so put pressure on pedal before undoing bleed er if you bleed too slowly air can be trapped in high spots in lines. Philiow313. should solve it by the posts here. Neil Quote Link to comment Share on other sites More sharing options...
philiow313 Posted February 3, 2004 Author Share Posted February 3, 2004 thanks neil. ill have it in the air tommorrow and ill look to see if there are bleeder screws elsewhere. Quote Link to comment Share on other sites More sharing options...
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