Bleeding brakes

[roadrunnerh]

I've always done the RR, LR, RF, LF - brake loose the bleeder and have someone in the car pump the brakes.

I read about gravity bleeding - where you fill the master cylinder and open all four bleeders.

How do you do it?

 

[sixgunrunner68]

Crack the bleeders and wait and wait and wait for a steady drip. If I install new parts (lines/cylinders)in the system I'll usually let it gravity bleed while I'm working on something else, but I will always bleed with a helper or vaccume pump as well. I guess what I'm saying is find someone to pump the pedal for you or use a vaccume or reverse injection pump. There's no benefit to gravity bleeding IMO.

 

[Big John]

I've been using a vacuum pump for a long time now. I've been happiest doing it that way.

I have a reverse injection pump that I bought for a song, but I've never used it so I can't tell you it's as good as people say. Next time I'll have to get it out.

I don't like pumping the brakes to bleed the brakes though. On a new system or at least new master cylinder, it's fine, but I've had too many older master cylinders fail within a couple weeks of bleeding using this method. I think the cylinder is worn and the piston seals get ruined when the pedal goes to the floor and the seals go across the ridges/sludge worn in the cylinder.