Please Help! abs conversion gone wrong

hey this is my first post, usually i find everything i need by searching. i read all the info on the ‘abs removal’ and so i attempted it…

i used the RS MC, stock abs booster, RS prop valve, and front RS hardlines. to bridge the gap to the rear, i used the old abs lines and bent them. removed all the abs junk, bled the system and went for a drive…

the pedal felt fine for a little while, but it was really high up, i noticed. but it was still driving normal. after a few minutes, i felt the car getting slower and the brakes were engaged while NOT braking. several minutes later, the brakes become fully engaged, like slamming them, but i wasnt; i was just driving. at this point, the brake pedal couldnt be depressed at all! The car became undrivable; i was toasting my brake pads, so i pulled over.
my question is what would cause so much pressure to build up in the brake system? If the rear lines that i bent were slightly crimped, could it cause this? please help. merry christmas.

Alan

are you lines hooked up right to the provalve if when putting in the new fluid it didn’t go pass rear1, drivers front2, drivers rear3, then passfront4 it is wrong, then re bleed the system, same order, also those lines need to be very tight, post a pic on those poss crimmped lines, so we can see, i hope i helped i finished my conversion went smooth

My girl had this same problem on her car…Her brakes engaged and she wasn’t pressing the brake pedal…it ended up being her master cylinder. Is the MC new???

awesome! ok im going to get my digital camera out hopefully tommorrow. i swear its hooked up right on the prop valve. ill try and take some pics. can the stock ABS booster be used with the RS MC? it does bolt up and everything, but somebody said i needed the RS booster as well. my gsr MC was completely shot, and the RS MC i got was free (along with the prop valve and lines). the pedal is hard as a brick though! i bled in the order of pass rear, driver rear, pass front, driver front. could not bleeding in the correct sequence really screw things up as to always engage the brakes? i thought it would make the pedal really soft. i was test driving up here at college (nobody around) and after the brakes developed a lot of pressure, i had to pull over, but came back a few hours later and the pressure had dissipated evidently, and i coasted back using the e-brake. if anybody can think of anything else, please let me know.

no, the MC is known good, my friend blew up his 90 rs and i removed it a week later. thanks though! are the boosters the same do you know between RS and GSR? that is bothering me, but they really look the same…

If you have the proportioning valve plumbed correct then your problem is likely you don’t have enough free play between the pedal pushrod and the brake booster. Check the pedal free play and adjust the booster push rod length. You need to have some slop to allow for expansion, use the factory settings and don’t go tighter.

figured it out! if you use the abs booster, and the non abs master cylinder (which means no flaring) you MUST add a total of four washers, two on each side between the MC and booster or face the consequences…as i did. :slight_smile:

ttt… how did you figure that out?

Did you try adjusting the pushrod first? Adding washers just seems wrong.
-nino

at this point, it doesnt seem to matter. ive never messed with the booster before… adding washers is fine (not orthodox) but there is plenty of room there. how do you go about adjusting the booster? im very curious, although my way got the job done, best i can tell.

Once again, how did you figure out that you could use four washers to accomplish your job?

well, it was more of a guess, but the RS and GSR MC’s are slightly different in how they match up with the stock GSR booster. The non-abs one obviously comes in contact with the booster rod differently. adding a gap there with washers corrects the problem, unless you want to switch to the RS booster when adding the RS MC. I would rather just add washers. Another alternative could be also to retain the original MC and flare (if using RS hardlines going to the GSR MC). This would have been my next alternative had adding washers not worked. I didnt want to buy a new MC though (my GSR one was going to the floor). I got the RS MC for free, like everything else i used.

There’s a lot of good info on this sight, which helped me out. :slight_smile:

The true solution is to retain the ABS MC since the piston is larger and therefore more desireable. Interesting find none the less.

this is why you just re-flare one of the lines with the different nut for the MC.

Vern… has this been done our your set of lines?

Nice job OS…

If you have the set from his wrecked GSR, then yes.

yea Schu, its done so you can use your GSR booster and MC. The right way :up:

Shweeeeet :ok: