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NO Brakes till pedal hits the floor.


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Cleaned up the rears, pads were good.

Replaced the front rotors and calipers, pads still good.

Put in a rebuilt power brake booster.


Bled the brakes rr/lr/rf/lf...bleed the master cylinder.  Bled the brakes again, farthest to closest.


Dammit,do I still have air in the master cylinder?  Will jacking the front of the car up and then bleeding the master  cylinder get  all the air out?


When I bled the master cylinder I did it back reservoir first, then forward reservoir.  Do I have to bleed them both at the same time?


Never had this issue with my american built cars, only this datsun.  Don't want to have to pay brake master $60 to power bleed it.




And the vacuum control valve to the booster.  It has an arrow on it, does that point towards the motor or the booster?


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Brake booster has no effect on brakes unless the engine is running, so discount it as the cause.


Suck on the one way valve. The side you can suck air through goes to the intake.


Need some back story. What's been done that you need to bleed the brakes?

You have rear disc brakes??? anything else that's been changed from stock???

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Hey Mike,


The car is all stock as far as the brakes go.  Since I put in a new power booster I had to pull the master cylinder.  I also replaced the rotors and calipers.


Essentially the whole brake system was drained of fluid.


Once I had everything back together I bled the right rear, right front, left rear, left front to get most air out.


The I bled the master cylinder, I bled the back reservoir first, then the front reservoir.


After which I bled the wheels again, right rear, left rear, right front, left front.  Farthest to closest.


I am guessing there is still air in the Master Cylinder, but what is a sure fire method of getting all the air out of it (the master cylinder).


Do you think jacking the front of the car way up, then bleeding the master cylinder would get all the air out?  I am thinking of american designs where the master cylinder is tilted up so air bleeds out.

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Get a short length of brake line with it's fitting. Screw it into the output of the master and bend the other end around until it will fit into the reservoir. Pump the brakes and the fluid and any air will be pushed right back into the reservoir where it will separate. When only clear bubble free fluids comes out. it done. Connect up the brake line and bleed normally.

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Bench bleed master cylinder 1st. Before even installing in car.


Good chance you just blew the seals in your new MC.



When you are bleeding, use a clear tube connected to bleeder draining into a clear bottle. This way air does not suck back into cylinder/caliper and you can watch that you indeed do not have air in that brake circuit.



You also need a helper. Way easier.

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I used a one man bleeder hose and bled the master cylinder, then bled all the brains again.  I has helped some (and I used a clear hose).

Bled the system until I saw no air bubbles.


Going to check the push rod tomorrow, as I failed to adjust the new one. My bad. Hopefully I can get enough clearance between the m/c and booster to check and adjust without having to start from scratch with the bleeding.

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