Hey guys, I need some urgent help please..

[mrcrazybutt]

So i did the z32 front brake swap w/ z32 master cylinder. The bleeders on the calipers are on the top. I bleed the brake from rear calipers to front calipers. Then i bled the ABS front one then rear. I have pressure. BUT... the pressure dissapear the moment i start driving! i have to "repump" the brake pedal to get just enough pressure to stop. And when i do stop... my wheels feels like it was gunna fall off because it was so shaky ! The master cylinder is brand new. I dont think that can be the problem... does anyone have any ideas?? I searched. And that is why i bled and bled and bled and same thing happened. I also bought new master cylinder because i thought it was the problem.. i really dont know any more solutions... can someone help ?? =[ its been too long since ive drive... any help would be appreciated.

[numbnuts240]

did you bench bleed the master cylinder? what order did you bleed the brakes? should go d/s rear, p/s rear, p/s front, d/s front.

[mrcrazybutt]

yep bench bleed the master cylinder yesterday.. still same results. it has pressure but then the pedal drops and have to repump to gain pressure. i bleed from the rear to front also... could it be the calipers by any chance? like is it not catching ? It doesnt have leaks or anything though, seems fine...

[nightsauce]

i had a similar problem. i went to midas for reasoning and they said "just because it doesnt leak fluid doesnt mean it doesnt suck in air." look for leaks somewhere

[motoman399]

DONT EVER TAKE YOUR CAR TO MIDAS!!! people are dumb as hell

i dont know much about the abs system, but i know it can bleed off pressure. also try bleeding just the brakes and not the abs unit. you may have to bleed the calipers several times to get all the air out.

[mrcrazybutt]

yeah there are no leaks.. maybe i should try one of those vacuum thing to get all the air out ? i kept bleeding with same results ... im so useless!!

[240life]

You got ABS? Dirty ABS sensors can cause erratic ABS pump operation and a soft pedal.

[mrcrazybutt]

yeah its pretty weird that i have abs on a s13. well to me atleast. i never thought of that. dirty abs sensor, ima check it out.

[240life]

I dont know to much about the s13 ABS, but my ford explorer did the same thing, I unplugged the sensors, no more issues because the sensors are not tripping out the pump.

[mrcrazybutt]

yep, tried to unplugg those abs sensor... looks like they are not going anywhere. I tried bleeding the whole system again. Its seems that i have a good pressure when the car sits idling. but as soon as it starts rolling, pressure drop. weird... it does seem like its the abs.

[speedeast]

I'm sure you checked, but is there a vacuum leak?

[240life]

yep, tried to unplugg those abs sensor... looks like they are not going anywhere. I tried bleeding the whole system again. Its seems that i have a good pressure when the car sits idling. but as soon as it starts rolling, pressure drop. weird... it does seem like its the abs.

Does the abs motor/ pump assembly have bleeders, maybe air pockets are trapped in the pump.

[chuckd502113]

i heard it makes a big difference if you only have the front z32 brakes instead of all 4 brakes the way you describe it it sounds like its the problem because the z32 master cylinder is meant for 12 pistons not 10 and what size m/c did you get do a little bit more research on the whole swap im not 100% sure but what i read about the swap because i have all 4 brakes that im waiting to swap into my 240 when i finish my sr swap