brianZortiz Posted June 5, 2010 Share Posted June 5, 2010 Hey hybridZ, I am currently doing a rear disk brake conversion and from a 280zx car. I installed everything, hooked up the new stainless steel brake lines and started to bleed the brakes. I had my mom pump the petal and I was opening the bleed valve, we bled on both sides and brake fluid seems to be coming out of bleeder. The pedal gets harder. I keep checking the master and keep filling up. We bled for a good 10 minutes per side(the rear). It still sink all the way towards the bottom. The brakes grab after 2-3 pump. It holds really good, but if I only press the brakes once it doesn't grab. When it is pushed in 2-3 times it does grab. Hope someone can help. Thanks brianZ Quote Link to comment Share on other sites More sharing options...
NewZed Posted June 5, 2010 Share Posted June 5, 2010 Hey hybridZ, I am currently doing a rear disk brake conversion and from a 280zx car. I installed everything, hooked up the new stainless steel brake lines and started to bleed the brakes. I had my mom pump the petal and I was opening the bleed valve, we bled on both sides and brake fluid seems to be coming out of bleeder. The pedal gets harder. I keep checking the master and keep filling up. We bled for a good 10 minutes per side(the rear). It still sink all the way towards the bottom. The brakes grab after 2-3 pump. It holds really good, but if I only press the brakes once it doesn't grab. When it is pushed in 2-3 times it does grab. Hope someone can help. Thanks brianZ Are the bleed valves on the top of the calipers, where they should be? On the front discs, it is possible to switch the calipers from side to side and end up with the bleed valves on the bottom. If the bleed valves are on the bottom you can never get all of the air out, there will be an air pocket above the bleed valve. A big one. I know this because my car came this way, and had your symptoms, and it took me quite a while to figure out. I don't know how the back calipers fit but it would be worth your while to make sure you got them on the proper sides. Quote Link to comment Share on other sites More sharing options...
brianZortiz Posted June 6, 2010 Author Share Posted June 6, 2010 I think I maybe need to bleed the front also. And the bleed valves in the rear are facing the front of the car at 180 degrees. It is not pointing up or down just straight with no tilt. The front brakes are left stock for now and haven't touched them. I also changed new steel lines in the rear connecting to rear way connecter and I think my brother might have applied the brakes without the steel lines. It might be that the 3 way connector might have got some air in the brake system. Quote Link to comment Share on other sites More sharing options...
brianZortiz Posted June 6, 2010 Author Share Posted June 6, 2010 Ok I will go ahead and try that method, but if I do the caliper mounting brackets will only be supported by two bolts as the mounting is for 3 bolts to be mounted on the hub. That's the way it was designed by zraceproducts. Is it also a possibility that my brake booster has anything to do with it? I am asking becuase mine is failing. When I apply brakes the RPM goes up to 1,500+. I also have no way of turning on the car because my carbs are sent out for rebuilt. Thanks Brian Quote Link to comment Share on other sites More sharing options...
Leon Posted June 6, 2010 Share Posted June 6, 2010 Ok I will go ahead and try that method, but if I do the caliper mounting brackets will only be supported by two bolts as the mounting is for 3 bolts to be mounted on the hub. That's the way it was designed by zraceproducts. Is it also a possibility that my brake booster has anything to do with it? I am asking becuase mine is failing. When I apply brakes the RPM goes up to 1,500+. I also have no way of turning on the car because my carbs are sent out for rebuilt. Thanks Brian The brake booster has nothing to do with the bleeding. However, the booster is done for and you have a vacuum leak because the diaphragm is broken. Time for a replacement! Quote Link to comment Share on other sites More sharing options...
brianZortiz Posted June 6, 2010 Author Share Posted June 6, 2010 Yup that thing is gone going to have to buy a new one (remanufactured). I don't mind it is towards the car and not the engine, since I'm swaping the l26 out for the l28et. Quote Link to comment Share on other sites More sharing options...
Headstrong280z Posted June 16, 2010 Share Posted June 16, 2010 (edited) I think I maybe need to bleed the front also. And the bleed valves in the rear are facing the front of the car at 180 degrees. It is not pointing up or down just straight with no tilt. The front brakes are left stock for now and haven't touched them. I also changed new steel lines in the rear connecting to rear way connecter and I think my brother might have applied the brakes without the steel lines. It might be that the 3 way connector might have got some air in the brake system. The bleed valves do NOT have to be facing directly up. They need to be towards the top of the caliper (vs closer to the bottom, if they were on the other wheel) because air naturally rises to the top side of the caliper. If you install the calipers as they are marked (R and L) it will be installed incorrectly. R and L are always with respect to sitting in the driver seat. So for the 280zx conversion, the caliper marked R will go on the drivers side, and L on the passenger side. Edited June 16, 2010 by Headstrong280z 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.