Master cylinder bench bleeding
Thread Starter
Racer
Joined: Apr 2004
Posts: 336
Likes: 0
From: Tucson
Master cylinder bench bleeding
I've always had brake issue. I've replaced the calipers and decided to bench bleed my existing master cylinder (which I didn't do when it was install years ago). I think I all of the air out, but have a couple questions.
1) I did push the rod in all the way (prior to reading other posts), but not hard. Definite harm? Any way to tell?
2) When pushing the rod in, the front reservoir has a strong squirt out of the small hole. The back reservoir only has a small squirt during the rod retraction. Is this normal or should both sides have a strong squirt on the push cycle.
Thanks guys.
1) I did push the rod in all the way (prior to reading other posts), but not hard. Definite harm? Any way to tell?
2) When pushing the rod in, the front reservoir has a strong squirt out of the small hole. The back reservoir only has a small squirt during the rod retraction. Is this normal or should both sides have a strong squirt on the push cycle.
Thanks guys.
Le Mans Master
Joined: Oct 2006
Posts: 8,939
Likes: 35
From: El Cajon California
Old School works for me, my daughter pressing the pedal to the floor, me tightening the bleeder screw etc if you do it in this sequence....
Left rear inner
Left rear outer
Right rear inner
Right rear outer
Left front
Right front
Left rear inner
Left rear outer
Right rear inner
Right rear outer
Left front
Right front
Burning Brakes
Joined: Apr 2008
Posts: 1,222
Likes: 93
From: shelbyville West Michigan
when bench bleeding, you just look for all the air bubbles coming out, both reservoirs full with the lines submerged, you don't need to push hard, and it won't be hard like on the car because it's not really building any pressure, just moving the fluid and/or any air...if you don't get all the air out, you will just work a little harder bleeding the rest of the system. no harm done.
Race Director
Joined: May 2006
Posts: 18,655
Likes: 2,561
since the master is old the part of the bore that normally doesn't have a piston seal slide by can develop corrosion. If you then cause the seal to slide past this corroded area by bench bleeding you can damage the seal.
