BRAKE MASTER CYLINDER PROBLEMO!

freakmachine

New Member
Feb 20, 2006
38
0
0
la mirada, ca.
okay boyz, i've hit the wall on this one. changed the master cylinder on my 89 mk3, after bench bleeding it i put on the car hooked up all the lines poured more fluid into it and tried to bleed the system, starting from the right rear brake i attempted to draw fluid from the caliper bleeder screw, NOTHING. kept vaccum on it for over 20 minuts and still NADA!!:icon_mad: I've tryed the old shade tree method pump five times and open the bleeder N-A-D-A. I went through the rest of the brakes, and the front two are OK, i went back to the rears and turned the air pressure up to apply more vac pressure. Got a little bit of fluid, and if i keep vac. pressure and close the bleeder, by disconecting the hose from the bleeder screw and if i open the bleeder again it will suck air in! WTF! a year ago i replaced the stock rubber lines with goodridge ones and used the vac. bleeder to bleed the system with out a problem. I thought that maybe the proportioning valve could be giveing me problems, so i removed it cleaned it blew air through it put it back and same problem. I just don't understand it but i know one or more of youzz has had this problem, so some-one please help. thanks guys.:1zhelp:
 

mkiiSupraMan18

Needs a new username...
Apr 1, 2005
2,161
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0
United States
Did you bench bleed the Master Cylinder? Relaced as in, a different used one or a new one? Were you getting fluid from both outlets on the MC?


I thought you were supposed to start the car, press and hold the brake while someone bleeds the brakes. Don't you also start with the pass rear->Driver rear->pass front->driver front when you bleed the brakes?

Just going w/ what I hear, btw.
 

supra90mkiii

Member
Apr 2, 2005
227
0
16
Racine, WI
i had the same EXACT problem last year when i replaced my master. I'm guessing you got a rebuilt one? so did i, actually, I tried two, with the same results. Get a new toyota one, works perfect for me now. i have a 90 turbo, with abs.
 

Aspec

Supra uber alles
Dec 22, 2005
261
0
0
Surprise, AZ
freakmachine said:
okay boyz, i've hit the wall on this one. changed the master cylinder on my 89 mk3, after bench bleeding it i put on the car hooked up all the lines poured more fluid into it and tried to bleed the system, starting from the right rear brake i attempted to draw fluid from the caliper bleeder screw, NOTHING. kept vaccum on it for over 20 minuts and still NADA!!:icon_mad: I've tryed the old shade tree method pump five times and open the bleeder N-A-D-A. I went through the rest of the brakes, and the front two are OK, i went back to the rears and turned the air pressure up to apply more vac pressure. Got a little bit of fluid, and if i keep vac. pressure and close the bleeder, by disconecting the hose from the bleeder screw and if i open the bleeder again it will suck air in! WTF! a year ago i replaced the stock rubber lines with goodridge ones and used the vac. bleeder to bleed the system with out a problem. I thought that maybe the proportioning valve could be giveing me problems, so i removed it cleaned it blew air through it put it back and same problem. I just don't understand it but i know one or more of youzz has had this problem, so some-one please help. thanks guys.:1zhelp:


The passages inside the rear calipers for the bleeders may be plugged with crap. Get a friend to help you. Before applying any pressure to the brake pedal, remove the right rear bleeder screw then have your friend slowly press down on the brake pedal. If you get fluid then the bleeder is clogged. Clean or replacement of bleeder.

If you did not get any fluid, re-install the bleeder and loosen the brake line then have your friend push down the pedal. If you get fluid then the passages in the caliper are clogged - Time for teardown or replacement.
*(hint: if this happens, remove the bleeder try feeding a small wire into the passage to dislodge said crap then bleed appropriately)

If you did not get fluid then the blockage or malfuction is further up the line.
repeat this process for each component until your issue is identified. If a computer controlled component (ABS) seems to be your issue than test as per TSRM.

Just as an aside, vacuum brake bleeders do not apply nearly as much pressure to the system as you would even lightly applying the brake pedal. Nor do they remove all the air from the system. Air in the brake system can be "sticky" for lack of a better term and will adhere to the insides of the lines and the vacuum "bleeders" will suck fluid right past the air. Vacuum systems should only be used as a means of "Flushing/Exchanging" the brake fluid and after being flushed the system should be manually bled as a final step.

*EDIT - Do not bleed your brakes with the engine running.

Hope this helps. Let us know
 
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SPD TRP

Formerly 3rdtimearound
Apr 12, 2005
526
0
0
62
Katy Texas
I have to change mine as well over the holidays, is there any special procedure to bleed if you have antilock?

Wayne
 

freakmachine

New Member
Feb 20, 2006
38
0
0
la mirada, ca.
Guys, thanks for all the info, i'll try them all and let you know what worked.
It sucks not beeing able to drive my car, so many (WRONG WHEEL DRIVE) hondas and x-box's to smoke, and on a cool day i'll even fry a G35 or two. thanks again fellas... ::salute::
 

Aspec

Supra uber alles
Dec 22, 2005
261
0
0
Surprise, AZ
mkiiSupraMan18 said:
I thought w/ the engine running holding the brake pedal would cycle it all through the ABS... ?

If functioning properly, fluid flows through the ABS freely engine running or not until sensor input to the ABS computer tells it otherwise.

If the engine is running while the brakes are bled it is easier to "aerate" (introduce air into by pumping pedal) the brake fluid and the increased system pressure applied by the brake booster can damage the master cylinder when the pressure is released too rapidly (opening the bleeders or brake lines).
 

p5150

ASE and FAA A&P Certified
Mar 31, 2005
1,176
0
36
Central Idaho
You need to resort to the "shade tree method".

Have somebody press down the pedal and hold it while you open the valve. Close it and have them release the pedal and do it again. It will work.

I think you are running into an issue with the vacuum "one man" kit.
 

freakmachine

New Member
Feb 20, 2006
38
0
0
la mirada, ca.
Boyz thanks again for all your posts, i havn't had too much time to fool with it, but a couple of days ago i did open both rear bleeders screws and left them open, you know the ol' gravity bleed method and stil bone dry! s#@t!!
WTF!!!!!! I mean WTF. I did the vac. bleed again and got some fluid
maybe a table spoon and that was it. I also did the brake pedal pump 5 times method and NADA'. i'm almost ready to shell out what those dealership pirates ask for a new one.:bigun2: the thing that sway me is that the master cylinder is a very basic part and i can see if maybe in the rebuilding prosses a seal or an o ring gets cut or torn, but never the less i should stil be able to bleed it. anywho keep em' coming, one of your ideas is bound to work. I MISS MY CAR:cry:
 

freakmachine

New Member
Feb 20, 2006
38
0
0
la mirada, ca.
Yup, my 13 year old son and i, he can push the brake pedal pretty good. Its not that hard, iv'e done lots of brake work on my own cars from chevys to vw's.
I'm starting to think that perhaps there is some ish. pluging up my lines. won't know tho til i bust it all apart, and as for the ol' shade tree method your right. alldata.com says to bleed the brakes that way.:dunno:
 

p5150

ASE and FAA A&P Certified
Mar 31, 2005
1,176
0
36
Central Idaho
Yeah - Ive also had good luck in the past with the shade tree method - Perhaps you could crack the lines one by one from the brake master cyl back to the rear to find a clog?
 

SPD TRP

Formerly 3rdtimearound
Apr 12, 2005
526
0
0
62
Katy Texas
freakmachine said:
Boyz thanks again for all your posts, i havn't had too much time to fool with it, but a couple of days ago i did open both rear bleeders screws and left them open, you know the ol' gravity bleed method and stil bone dry! s#@t!!
WTF!!!!!! I mean WTF. I did the vac. bleed again and got some fluid
maybe a table spoon and that was it. I also did the brake pedal pump 5 times method and NADA'. i'm almost ready to shell out what those dealership pirates ask for a new one.:bigun2: the thing that sway me is that the master cylinder is a very basic part and i can see if maybe in the rebuilding prosses a seal or an o ring gets cut or torn, but never the less i should stil be able to bleed it. anywho keep em' coming, one of your ideas is bound to work. I MISS MY CAR:cry:


I can tell you, $188 and some change fron Jeff at champion toyota, ordered it yesterday.

Wayne
 

freakmachine

New Member
Feb 20, 2006
38
0
0
la mirada, ca.
No not yet, i order the new master from champion yesterday and hope i get it soon.
Upon doing more reaserch and diagnostics it all pointed to the master, oh well live and learn remanufactered ish some times is realy ish! anywayz, soon as i get it it going on that day or night. I'll post my results later.:x:


ps. sorry for the late reply, got too many irons in the fire;)