Bleeding Brakes!

[John Turney]

Recently, I went from master cylinders (MCs) with integral reservoirs to remote reservoirs. I used my Gunnison Eezibleed and it worked great. It never worked with the integral reservoirs because I couldn't get a good seal.[h=1][/h]

 

[Bob_Spidell]

"... Norman Nock's book recommends against using a pressure bleeder ..."

Did Norman give a reason? My pressure bleeder works a treat; you just can't use anything over about 10PSI:

 

[steveg]

Lin, can you use this with your Dennis Welch slave cylinder bleed hose? My vacuum bleeder won't work with the end fitting that comes with that hose.

Not sure why this would be true. Looked at the DW hose on their site, and it has a standard bleed screw on the end.

 

[Rob Glasgow]

Steve, the problem is the bleeder fitting is attached to the hose with a swivel fitting. When you loosen the valve with the vacuum bleeder attached, it draws air through the swivel fitting. The other problem with the hose is if you try to use the old standby method of attaching a piece of tubing to the valve and pumping the brake pedal, as soon as you loosen the bleeder valve, the fluid leaks all around the swivel fitting a makes a real mess. The only plus to the DW hose is that you can bleed the slave easier than the original setup. But also makes a mess. If I had known, I would have made up a solid extension with a soldered end fitting and bleeder valve. Live and learn.

 

[steveg]

Steve, the problem is the bleeder fitting is attached to the hose with a swivel fitting. When you loosen the valve with the vacuum bleeder attached, it draws air through the swivel fitting. The other problem with the hose is if you try to use the old standby method of attaching a piece of tubing to the valve and pumping the brake pedal, as soon as you loosen the bleeder valve, the fluid leaks all around the swivel fitting a makes a real mess. The only plus to the DW hose is that you can bleed the slave easier than the original setup. But also makes a mess. If I had known, I would have made up a solid extension with a soldered end fitting and bleeder valve. Live and learn.

Rob - thanks for the clarification. Sounds like a good reason to avoid the DW product. The solid line of the Doug Reid-type is the better way to go.

 

[bighealeysource]

The old front drum wheel cylinders had a tiny ball under the bleed screw; I'd encountered cars where the bleeder was tightened down so much that the steel ball was locked into the aluminum casting (just putting that out there...).

I really like Brinkerhoff's suggestion; never needed to try that, but I can see the advantage for problematic circuits that don't act right!

The one thing that comes to mind, is did you bleed the m/cyl by itself__often referred to as bench-bleeding? Are these the original self-contained reservoir m/cyls, or the combined reservoir (the type used through the end of Healey production)? Even with the m/c mounted in the car, you can still bench-bleed it with a scrap of old tubing. Substitute the tube for the car's brake pipe, and make sure it reaches below the level in the reservoir. Several easy strokes will free the m/c of any air present.

When bleeding the front drum brakes, I don't rely on getting all the air out of the two (2) wheel cylinders through the one (1) bleed screw. Instead, I crack loose the fittings on the connecting pipe(s) in sequence. chasing the air out of the circuits. You can do this same practice at every union as well.

If there's air in there, cracking every union while maintaining a LOW (15 PSI is plenty adequate) column of pressure on the reservoir will expel it all eventually!

Picture of bench-bleeding in situ:

scrap-tube coming off the brake m/c:

opposite end of tube into the reservoir (remote on this MKIII):

Good luck (I KNOW how frustrating this can be, but you'll get it__the car never wins...)!

Hey Randy,
Been ages and still miss BN6L/964 but as you know had the 100M for about 13 years now. Got a brake bleeding issue similar to what is discussed on this thread. Do you by any chance still have pictures of how you bled the master cylinder with it in place ? And assume where you say maintain a low 15 pounds of pressure is with a Motive unit ? Have eliminated everything except the mc and it is not leaking buy maybe
has an air bubble hiding in there after I lost most of my fluid doing a brake cylinder change.
Thanks,
Mike Lewis