Bench Bleeding the Master Cylinder??

[90blzr]

My truck has been sitting for some time now, and I need to bleed the brakes. The master has been empty or nearly empty. I have never had to bleed a master cylinder before. How do I go about doing it?

I am gonna make one of those pressure bleeders like KidJethro made for bleeding the brakes, but obviously I need to bleed the master first.

Can I do it on the vehicle, or do I have to take it off?

That should be it right? the four corners and master cylinder....would the proportioning valve have air in it? How do you bleed that if it does?

Thanks.

 

[Muddytazz]

Bench bleeding the master is easier while its mounted in the vehicle versus a bench vise.


I think you can buy a master bleeding kit, if not, just get yourself a couple of fitting to screw into the brake line holes in the side of the master(the fittings need to be the kind that will accept an air hose on the other end)get yourself a couple lengths of hose to go from the fittings to the resivours(sp?). Someone watch the fluid and someone slowly pump the brake peddle.

When your pumping the peddle, make sure to NOT fully extend or fully release. This will get the air out of the master

 

[RootBreaker]

Bench bleeding the master is easier while its mounted in the vehicle versus a bench vise.


I think you can buy a master bleeding kit, if not, just get yourself a couple of fitting to screw into the brake line holes in the side of the master(the fittings need to be the kind that will accept an air hose on the other end)get yourself a couple lengths of hose to go from the fittings to the resivours(sp?). Someone watch the fluid and someone slowly pump the brake peddle.

When your pumping the peddle, make sure to NOT fully extend or fully release. This will get the air out of the master

that is what we do.... called truck bleeding !!!!!

 

[Muddytazz]

that is what we do.... called truck bleeding !!!!!

Yep, cause if you mount the master in a vise to bench bleed it, you have to use both hands to push the rod, while with truck bleeding, you can either sit there and pump the peddle or stand there and watch the master while drinking a beer

 

[90blzr]

Thanks!
But why dont you want to give full pumps of the brake pedal?

 

[Muddytazz]

Could damage the seals on the inside. There is actual instructions that come with new masters that explain this. Something like stopping about an 1" short of travel each direction.