Bench bleeding master cylinder

[tez]

Is it possible to bleed the air out of a master cylinder on the car, or should it really be done off the car?

[SIMMO84]

What kind of car ive always done it on the car havent had any problems.

[tez]

Sorry missed that important bit, 92 Hilux. Cant seem to get a pedal feel after the master cylinder has been disconnected

[SIMMO84]

You can get dramas bleeding the proportioning valve i usually just crack the bleeders, sit back and have a beer and let gravity work for you, works every time for me

[tez]

You can get dramas bleeding the proportioning valve i usually just crack the bleeders, sit back and have a beer and let gravity work for you, works every time for me

Will gravity bleeding bleed the air out of the master cylinder too? At the wheels and proportioning valve the fluid comes out with no air at all.

I just cant get a pedal!

[SIMMO84]

Did you bleed the master cyl on the car before you put the lines on?
is the pedal going to the floor, does it pump up hard?

[tez]

Did you bleed the master cyl on the car before you put the lines on?
is the pedal going to the floor, does it pump up hard?

Yeah the method I used which may or may not be right is I hooked two lines into the two outlets and fed them back into the reservoir and did it that way.

The pedal does go to the floor and doesnt pump up hard when the car is running.

[SIMMO84]

better to use your fingers over the holes get someone else to pump the pedal just hose off the mess asap

[tez]

Might try that if I have a helper on hand tomorrow, or else i'll drop it in to the brake guys to do it

Brakes on this Hilux are shitting me

[SilverBulletBM]

gettin old lines and screwing them into the master and pumping the pedal is the best way to do it by urself. When i have trouble gettin air out i usually crack the furtherest away and start pumping until i see air come out, move onto the next and do the same. Cracking them all and chilling for a while will work as well.

[tez]

Thought I had done that all already. Did the master, then did all the times until clear fluid was coming out.

The pedal feels ok with the car off and no vacuum assist. When the car is switched on the pedal goes to the floor. Its a brand new master cylinder I have in there too.

I dont think its the booster because it should give me a hard pedal if the booster isnt working right witht the car switched on?

[Jacked]

sounds like air in the system. May also be the pedel to booster has been adjusted (if it has an adjustment there) can make it impossible to bleed

[SilverBulletBM]

Open the nipple and keep pumping, even if its clean, sometimes it can take ages.

[jtraf]

you do have to bleed it from all four points in the system......air will come out even after clean fluid comes out.........couple litres of new fluid is all you need and some help......

with car off and cap off the booster with full of fluid pump the pedal till hard......hold the pedal firmly and crack the brake nipple for a couple seconds....close off nipple and repeat.....

pump pedal...hold...crack the bleed valve and close and keep doing that till all air out.....