Rear disc conversion?

[hr220a]

I'm on the last few details of my SAS and, as expected running into stupid little problems that are holding me up. In the rear, I'm running a 95 Isuzu Rodeo with disc. My brakes are crazy spongey. they get hard with the truck off but, unde vacuum pressure, they go soft. They should be bled well enough but, then again, they sat open for a few days first so who knows. Could it be an incompatibility with the stock proportioning valve/ABS module or should I just keep on bleeding?

[tmorgan4]

I'm assuming you didn't install the bigger master cylinder that quite a few people have gone to?

[hr220a]

No I did not. That could be it though. The disc calipers are definately going to need more fluid to lock up. What master is everyone using?

[tmorgan4]

Seems to be a few ways to do it.

http://nissan4wheelers.com/eve/forums?a=tpc&s=227600023&f=777600023&m=67110558901&r=67110558901#67110558901

http://nissan4wheelers.com/eve/forums/a/tpc/f/885603133/m/52110066021?r=16210396021#16210396021

[CurleyMan]

I'm not using one but i have a different vehicle. Have you installed a brake pressure modulator?

[Allen Cox]

Did you remove the ABS module? Or are still running everything through that?

If the system was open for a while, then there could be air trapped in the module.

[hr220a]

the abs module is still there, though the abs isn't hooked up. we thought about using a brake pressure modulator, but I knew others have done the swap so I wanted to see what they did first. ill try bleeding them again tomorrow and go from there.

[DamnHippie]

I've found it useful to tap on the steel brake lines with a wrench, especially where the coils are up front, after a ton of air gets into the system. I think little bubbles cling to the lines inside, and tapping releases them then they combine into bigger bubbles and come out when you bleed them. Also, if air got into the master cylinder you may need to bench-bleed it. That happened to me a couple times; no amount of regular bleeding helped, I had to take the master off and pump it while holding it at a couple funny angles to get all the air out.

[hr220a]

I've found it useful to tap on the steel brake lines with a wrench, especially where the coils are up front, after a ton of air gets into the system. I think little bubbles cling to the lines inside, and tapping releases them then they combine into bigger bubbles and come out when you bleed them. Also, if air got into the master cylinder you may need to bench-bleed it. That happened to me a couple times; no amount of regular bleeding helped, I had to take the master off and pump it while holding it at a couple funny angles to get all the air out.

Cool. I'll definately try that