Bleeding Hayes Brakes
Posted: Sat Aug 20, 2005 5:01 pm
'It finally came to me as to why I've been having trouble bleeding the brake system and still seem to be getting air into the system.
The master cylinders in the 24's are installed at a +10 degree angle to the ground. Unless you can get the plunger/cup assembly to completely reach full travel, and maybe not even then, you will have a small pocket of air just above the outlet port.
What I did yesterday was to elevate the tail of the fuselage about 4 feet. 3.25 feet will bring the master cylinder to about a 0 degree tilt. Then feed brake fluid through the bleeder screw, up through the system to the master cylinder. I depressed the brake pedal a couple time break up the trapped air so it would either move out of the system and up the feed hose to the supply reservoir, or to suck it into the master cylinder reservoir on the return stroke. When the lower part of the master cylinder filled completely with brake fluid, I could then see the brake fluid start to come up through the compensator hole into the master cylinder reservoir.
Bob Etter
PO Box 974
Tonopah, NV 89049
775-482-6820
rletter@citlink.net
[Non-text portions of this message have been removed]'
The master cylinders in the 24's are installed at a +10 degree angle to the ground. Unless you can get the plunger/cup assembly to completely reach full travel, and maybe not even then, you will have a small pocket of air just above the outlet port.
What I did yesterday was to elevate the tail of the fuselage about 4 feet. 3.25 feet will bring the master cylinder to about a 0 degree tilt. Then feed brake fluid through the bleeder screw, up through the system to the master cylinder. I depressed the brake pedal a couple time break up the trapped air so it would either move out of the system and up the feed hose to the supply reservoir, or to suck it into the master cylinder reservoir on the return stroke. When the lower part of the master cylinder filled completely with brake fluid, I could then see the brake fluid start to come up through the compensator hole into the master cylinder reservoir.
Bob Etter
PO Box 974
Tonopah, NV 89049
775-482-6820
rletter@citlink.net
[Non-text portions of this message have been removed]'