BTF/PTM Posted March 26, 2010 Share Posted March 26, 2010 So the 72 240z has a nice case of nose dive when braking and the whole system feels overall soft. Stock brakes - fresh pads/shoes and newly rebuilt booster - except for the oversize MC. The shop that did the booster advised me that the soft feel may be due to the larger MC preferring rear discs and/or bigger front calipers. Anyone have experience with similar symptoms? As for the nose dive, could this be a related thing? Quote Link to comment Share on other sites More sharing options...
S130Z Posted March 26, 2010 Share Posted March 26, 2010 Nose dives typically mean that your front struts have gone bad. I would suggest starting there by replacing your struts and see if this fixes your problem. Quote Link to comment Share on other sites More sharing options...
jasper Posted March 26, 2010 Share Posted March 26, 2010 Why was the brake system repaired?? Was dive a problem prior to repair?? How many miles since repairs?? Are the brakes beded in? Is there still air in the system. Adjusted properly??? Since so many changes were made at once, you have many variables. Front struts should not be your first move......... Quote Link to comment Share on other sites More sharing options...
hoov100 Posted March 26, 2010 Share Posted March 26, 2010 Nose dives typically mean that your front struts have gone bad. I would suggest starting there by replacing your struts and see if this fixes your problem. I would check them, before even removing or replacing anything. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted March 26, 2010 Share Posted March 26, 2010 I'm going with reaction disk. If it falls out the pedal will feel soft (often people say "I've bled the system 20 times and still don't have a pedal") and then when the brakes finally work when the pedal is near the floor they'll be on really hard. Search and you'll find other people with the same problem. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted March 27, 2010 Share Posted March 27, 2010 One more thing: Large master = harder pedal pressure for the same amount of pressure at the caliper. Small master = softer pedal and more pressure at the caliper. As said before, losing the reaction disk makes everything funky, and the pedal feels soft until the brakes come on really hard. Quote Link to comment Share on other sites More sharing options...
BTF/PTM Posted March 30, 2010 Author Share Posted March 30, 2010 Thanks everyone, I'll be pulling the booster this afternoon to see for myself. I called the shop that rebuilt it, their response was absolutely no help - they don't have much to do with booster rebuilds since they just outsource it, all they do is R&R the booster itself. They couldn't tell me anything about how the 15/16" MC operates compared to the factory 240z MC becuz they didn't know what size the factory one was in '72. I should have just taken the booster out and rebuilt it myself. This is what I get for spending too many years without a project vehicle and becoming fearful of certain jobs. Sorry for the rant, guys. One more thing - if observation serves me right, I won't need to disconnect anything from the MC when I pull it away from the booster, I just need to be gentle when bending the brake lines forward to clear it. Is this correct? I want to be ready for it if I need to disconnect brake lines and catch fluid and then prepare for bleeding the MC and brake lines if it's required. One more thing: Large master = harder pedal pressure for the same amount of pressure at the caliper. Small master = softer pedal and more pressure at the caliper. As said before, losing the reaction disk makes everything funky, and the pedal feels soft until the brakes come on really hard. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.