How to fill/bleed totally dry brake system?

[just plain john]

I pulled the m/c, claipers and rear end during my build. This is a vacuum system that came on my 81 El Camino stock. Having never done this before, what's the procedure for filling the system? Speed bleeders went back on when I put it back together. Thanks for any tips.

 

[Red Regal T]

Just open all the bleeder and fill the MC reservoir and allow the bleeders to drip fluid until you feel the system is filled. Close the bleeders, in the normal order, farthest from MC first, and you should have a pedal.

 

[just plain john]

Many times I've heard the term bench bleed. No mention of it here?

 

[regan j]

Bench bleed

is when u bleed the MC using a bench vise and screwdiver along with the fittings and flexible hoses to get air out of the MC before u put on the car.

 

[Red Regal T]

is when u bleed the MC using a bench vise and screwdiver along with the fittings and flexible hoses to get air out of the MC before u put on the car.

Exactly. Forgot to mention that. :redface: The master cylinder must be bench bled before installing or you'll never get the air out of the system.

 

[just plain john]

Forgive my newbieness, is there a tutorial for that?

 

[Red Regal T]

You need to run hoses from each of the orifices on the side of the MC, into the reservoir filled with clean brake fluid. With the MC secured in a bench vice, you pump the plunger with a rod or screw driver. The ends of the hoses must remain submerged. This pumping forces the fluid through the MC and purges the air. The problem that you have is finding fittings that screw in the outlets from which you can attach the hoses that curl into the reservoir. If your el camino is junk, just cut those brake lines that are attached to the MC a few inches long, and attach hoses to those lines for bleeding the MC.

 

[1fast6]

Forgive my newbieness, is there a tutorial for that?

yes there is.
YouTube - Bench Bleeding

 

[1quick6]

When I did my hydro conversion, I bled the MC on the car. The only additional thing I had to do was jack the car up so the MC was level. Not a big deal since it was up in the air for bleeding anyway.
The pic below shows it before I jacked the car up to level the MC. Those port adapters are available at NAPA for a few bucks. No other parts stores had them.

 

[Taylor04]

When I did my hydro conversion, I bled the MC on the car. The only additional thing I had to do was jack the car up so the MC was level. Not a big deal since it was up in the air for bleeding anyway.
The pic below shows it before I jacked the car up to level the MC. Those port adapters are available at NAPA for a few bucks. No other parts stores had them.

I did the same thing during my hydroboost install. Bolt the MC on the car, thread fittings with hose into MC, make sure both lines stays submerged in the reservoir with plenty of fluid. Then slowly and consistently pump the brake pedal and watch the MC reservoir to make sure it stays full of fluid. After about 15-20 times it is usually pretty good, or when you can't see anymore air coming out of the line. When you are ready to hook up the actual brake lines to the MC do them one at a time and quickly to minimize air getting in the system.:biggrin:

 

[bsdlinux]

Red Regal T

When I bought a vacuum conversion kit for my GN some years ago from John, he had already included the old lines that were cut off and bent back into the reservoir for me.. saved me some time... Thanks John :biggrin:

 

[just plain john]

yes there is.
YouTube - Bench Bleeding

Hmm, no tubes into the resovoir were used here.

 

[1quick6]

Not everyone uses tubes. The MC comes with plugs you can use, but most prefer the screw in port adapters and tubing so you can see what is going on. If you are doing it on the car, clear tubing is great so you can see what is happening while you work the pedal.

 

[Red Regal T]

Hmm, no tubes into the resovoir were used here.

I never saw that method before, but apparently, it works, I guess. When you buy a new or rebuilt MC as I have from time to time over the years, nipples and hoses are provided for bench bleeding, as illustrated in 1quick6's post.