Brake problems....weird

[RatedR]

1991 1500005spd fastback

Alright, I know I've done basically everything I know I can do to a brake system. I've bled all the darn calipers, replaced the pads, replaced the brake booster and the master cylinder. My problem is that it seems like there's still air in the system because everytime I start the car, pump the brakes, air slushes out. It gets stiffer later on....but its not the same. Also, I noticed that even if I'm not on the brakes and I'm on a hill, the car doesnt roll back in neutral. It seems like its stopped on there by the brakes. I dont know what else I should replace. I should probably mention that a while back, before I replaced the MC, the brakes locked up on me almost permanently. I had to wait till the system free'd itself up before I could even more the darn car. Any info would be nice. TIA

-R

[180fan]

well when the car is off, press the brake pedal 3 times. with each press, does the brake pedal stop futher and further up (closer to you)? If not, then it's probably your brake booster (even though it's new).

now if the booster's fine, you may have to check your car for a leak somewhere as air might be creeping in through there. If it's not from a leak, then re-bleed your brakes. are you doing this with a friend and in the proper order? Remember, one person presses the pedal while the other watches the brake fluid. Proper bleeding order on the S13:

left rear (drivers side)right rearleft frontright front.

now that's assuming you dont have abs.

note: when replacing your bmc, remember that although fluid is coming out without air bubbles, that could have just been old fluid that was still in the line. Bleed thoroughly. I just did my buddy's bmc last weekend, and went through about 1.5L to fully flush the entire system and to do a double check to make sure there were no bubbles.

[RatedR]

Yeah man, I've done all that. Everything's been done properly too. Dunno what else I need to do. The brake booster does check out to be alright. I doubt there is a leak, no fluid under the ground when I leave it or bleed it.....

[Scott McLellan]

Did you "bench" bleed the master cylinder before you put it in. This has to be done or you will never get all the air out. Also, what do you mean your brakes locked up?

[NISTECH]

if you have abs, try bleeding the system with the car running. this will be an interesting event for ya if the abs motor starts. but by what you said about feeling like the brakes where applied I wonder if a valve has jammed in the abs unit.

[RatedR]

well, i think its doing better now. I adjusted the push rod and freeplay. Does it a lot less now. I didnt really bench bleed the MC, but I did something similar. I attached three hoses to the MC and put it into the reservoir and pumped the **** out of the pedal. This should've given me the same results....right?

[NISTECH]

yep

[Scott McLellan]

Does your car even have ABS?

[RatedR]

i really dont think so, there's no ABS light on the dash and I've locked up the brakes before without any signs of ABS. Another thing I noticed is that it lets up when I put my foot under the pedal and raise it. Seems like its stuck on the brake itself or something. What else should I look out for?

[RatedR]

Any other thoughts????

[Holisticbeatz]

Proper bleeding order on the S13:

left rear (drivers side)right rearleft frontright front.

I'm assuming your car is USDM and the driver is on the left side. The proper way to bleed:

Passenger side rearDriver side rearPassenger frontDriver front

You want to bleed the calipers in order from the furtherest to nearest away from the brake master cylinder.

[RatedR]

I already bled all the calipers 10 times over in that order, no kidding.

[Holisticbeatz]

Did it 10 times in that order eh? Perhaps you should use a vacuum pump to suck out any pesky air bubbles. If that doesn't work, then perhaps you might have a leak in your brake hard line.

[180fan]

Holisticbeatz I got that info from the usdm fsm. might want to check under the car as you'll find that the drivers rear and the drivers side tubes have longer brake tubes. More readily visible from the underside when checking out the rear calipers. Just because the bmc is on the LHD, doesn't mean that the car was originally spec'ed for the bmc to be on the LHD. It was actually meant to be on the RHD, nissan just merely lengthened the front lines and put another longer (vs the RHD spec) line that runs to a distribution block just under the firewall that runs to the rear.

[NISTECH]

check your lines from front to back for kinks in it cause it to hold pressure at one of the wheels. check your caliper pins for binding in their bores. also I dont know if you have rear drums or rotors. if you have drums is the drag set properly on your rear brakes?

[RatedR]

rotors on the back. I also noticed that if I stick my foot under the pedal and raise it manually, the brakes ease up. And I also noticed that if they locked up, I have to pump the pedal as far down as I can (both feet) and then it'll ease up. Seems like the free play above the pedal isnt really free.....

[Scott McLellan]

Is there something in the brake pedal assembly itself that could be binding possibly like a bent brake pedal lever if that is even possible, or where it pivots? Also, when you bled the calipers did the fluid coming out appear normal?