how to bleed a brake Master Cylinder while it is on the car???

 

you're suppose to do it in the car. theres a whole procedure to it but basically you loosen the bleed nipples and have someone pump the fluids through to get air bubbles out. anyways, i just thought you needed the bump...

 

yes thanks..

are you talking about bleeding the calipers? of the actually master cylinder??

it said to bleed the MC by having someone press the brake and hold it in, then loosen the fittings to release air and fluid.. ???

they werent talking about the brake calipers..

 

i could be wrong but the only way to bleed the brake system is while it's in the car pumping air through the calipers. i don't see any reasons why the master cylinders needs to be bleed because its going to have to be done after anyway - through the calipers.

 

The Master Cylinder should be bench bled before being installed on the car. Usually when you buy a reman. unit, it will come with two hoses that you use to loop the brake fluid back into the resevoir. Then you actuate the piston untill you don't see any bubbles coming up out of the hoses. Then install on car and bleed all four calipers.

If you don't bench bleed the MC before installing, it just takes alot of pumping and releasing at the calipers to bleed the MC. And then all the air is being pumped thru the brake lines, which has to be bled out at the four corners. But it can be done.

 

can i bench bleed the master cylinder while its on the car? if i put the 2 tubes into the master cylinder, then pushed the pedal a bunch of times, would that be the same as putting it on a bench, and pushing the rod in?

 

Ya, that will work, push slowly about 75% down on the pedal about 10 times and let another observer tell you when the bubbles stop.

 

ok wtf??? ive bleed my brakes 3 times now.. so each caliper ive bleed 12 times.

everytime when my pedal pusher starts and pumps for 8 times and holds, i loosen the bleed screws on the caliper and a lot of bubbles and fluid come out.

on the 2nd, 3rd and 4th times, there are no bubbles coming out, but it also seems like there is no fluid coming out either.

so i tighten up that caliper and continue on to the next one. The same thing happes for each caliper.

then at the end, when i tighten everything up and top off the resevoir, the brakes are still soft.

Like i said, I have done this procedure 3 times!!!!! and each time, the same result.

wtf is going on???

could the master cylinder be no good??? i dont know..

do i need to adjust anything? like that push rod that goes into the master cylinder?? is it just taking the old MC off and putting the new one on the same way the old one came off??

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Sam92Teg &raquo;</TD></TR><TR><TD CLASS="quote">Ya, that will work, push slowly about 75% down on the pedal about 10 times and let another observer tell you when the bubbles stop.</TD></TR></TABLE>


so dont press the pedal all the way down, which means the that the push rod wont go all the way in? shouldnt i push the pedal all the way down??