Gavin Posted January 28, 2006 Share Posted January 28, 2006 I bled the brakes on my 78 all day, but the pedal is still soft on the first push. When I jump on them the fronts lock up, and the two of them seem even at least. So I would gather my problem is in the rears. After the first pump everything seems even. My master cylinder was just recently replaced, and the front calipers and rotors were swapped from an earlier 280. What could be causing this? Thanks, Gavin Quote Link to comment Share on other sites More sharing options...
jt1 Posted January 28, 2006 Share Posted January 28, 2006 Either you've still got some air in it, or the rear brakes need adjusting. If the pedal's firm on the second stroke, I'd try adjusting the rears till the shoes just drag the drums. If the pedal's got some softness on the second stroke, bleed it some more. Start with the master, then the rears, then the fronts. It could be a combination of both. Also have somebody mash the pedal and hold it, and look to see if any of the flex lines are ballooning. jt Quote Link to comment Share on other sites More sharing options...
iaconsultants Posted January 28, 2006 Share Posted January 28, 2006 Most people are not patient enough or can not find a person to work the brake pedal to bleed them correctly. You could do a very slow gravity bleed and it will take you about 24 hours of slowly let it bubble out, or you could try speedbleeders. http://www.speedbleeder.com/ I bought some for my car, one person can do it and it works really well. They are not bad for the price and as much as you have to play with the brakes and other things on these old Z's these things made it nice, just I suggest use a container not a plastic bag and shove some paper towels in the bottom. The key yhing is to make sure there is no bubbles in the rubber tube when you are bleeding and you will know your done. There is one other thing you might want to check if it is not air in the lines. Are you running old rubber brake lines because they can balloon out and you will get a similar foot feel. Quote Link to comment Share on other sites More sharing options...
SHO-Z Posted January 28, 2006 Share Posted January 28, 2006 I had a simular problem on my brakes. Bleed the all 4 brakes and still had air in the system. Found out I needed to bleed the master cylinder. I have a ZX master on my 260. Two squirts and the brakes worked great. Quote Link to comment Share on other sites More sharing options...
Guest Trudge Posted January 28, 2006 Share Posted January 28, 2006 I had the same problem after installing the Toyota calipers on the front. Turns out I had the calipers upside down which put the bleeder valve on the bottom. Couldn't get the air out! Lesson learned Quote Link to comment Share on other sites More sharing options...
Gavin Posted January 28, 2006 Author Share Posted January 28, 2006 I bled the master. Doesnt the handbrake cable adjust the rears each time its pulled? Also, what does gravity bleeding involve? Quote Link to comment Share on other sites More sharing options...
Miles Posted January 29, 2006 Share Posted January 29, 2006 Gavin Did you bench bleed the MC? Proper bench bleeding is essential to getting all air out of the system. I purchased a pressure bleeding system for about $100.00. It is a little messy, but I can now bleed my brakes without an assistant and it forces all air out of the system Miles Quote Link to comment Share on other sites More sharing options...
Gavin Posted January 29, 2006 Author Share Posted January 29, 2006 Bench bleed? Whats that? If its with a machine like you said, nope. I'm going to talk to some shops on monday if I cant solve the problem by then. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted January 29, 2006 Share Posted January 29, 2006 Regardless of whether or not the ebrake is SUPPOSED to adjust the rear brakes, you might want to see if you can manually adjust them. The automatic adjusters are pretty finicky and lots of times don't work at all. Bench bleeding is when you put the master in a vice, attach hoses to the bleeders and run them right back up to the reservoirs, then use a punch or a screwdriver to cycle fluid through the master. You don't have to bench bleed though. You can bleed the master on the car just fine. One thing you don't want to do is push the brake pedal down quickly when you're bleeding the master. You'll see if you do then it causes the fluid to squirt back into the master and you end up with thousands of little bubbles in the fluid. These little tiny bubbles get into the system, and then you're stuck again with air in the lines. So push slowly when you're bleeding the master. Quote Link to comment Share on other sites More sharing options...
Gavin Posted January 29, 2006 Author Share Posted January 29, 2006 I'm starting to think it is just the adjustment.. I'll report back when I have fiddled more. Quote Link to comment Share on other sites More sharing options...
80LS1T Posted January 29, 2006 Share Posted January 29, 2006 I had the same problem after installing the Toyota calipers on the front. Turns out I had the calipers upside down which put the bleeder valve on the bottom. Couldn't get the air out! Lesson learned Like stated above, are you sure you put the bleeders on the new calipers pointing up? Always check the obvious! Pedal height is adjusted from the rear brake adjustment. I would adjust the rear brakes up, bleed the master, bleed the right rear, bleed the left rear, bleed the right front, and then bleed the left front. If that doesnt fix it then you have a part thats not working correctly. Probably your master... Guy Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted January 29, 2006 Share Posted January 29, 2006 Bench bleed. I just bleed my clutch MC this evening. Disconnect the line at the MC and held my finger over the hole while pumping the pedal. When it squirts, stop pumping and reconnect the line. Works every time. Quote Link to comment Share on other sites More sharing options...
v80z Posted January 30, 2006 Share Posted January 30, 2006 Had a similar problem. Someone here helped me out. I had the calipers on the wrong side. A quick switch right toleft fixed it. Remember bleed screwsgo above the brake lines. Quote Link to comment Share on other sites More sharing options...
Clifton Posted January 30, 2006 Share Posted January 30, 2006 When I put my Wilwoods and new MC I couldn't get it right until I bled the MC. You can do it on the car just run the fuild back into the resevoirs. If it's still soft it could be the reaction disk. Quote Link to comment Share on other sites More sharing options...
Gavin Posted January 30, 2006 Author Share Posted January 30, 2006 Calipers are right side up. I now realize I also should have mentioned that I changed the rear shoes as well right before this problem started. Rained today so I didnt get a chance to pull it apart. So from what I understand I have to make sure something is catching on a cog under the drum somewhere? This is easy to fix? I dont have my manual up here at school. Quote Link to comment Share on other sites More sharing options...
Gavin Posted January 30, 2006 Author Share Posted January 30, 2006 I had them bled with a machine and a lot of air came out of one of the rears. Pedal feels awesome now. Thanks! Quote Link to comment Share on other sites More sharing options...
280zNHChris Posted January 31, 2006 Share Posted January 31, 2006 MightyVac should help. If not still a good investment $29, just used it to test my EGR valve on my ranger. Quote Link to comment Share on other sites More sharing options...
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