Just upgraded front to disk. Put a new new MC and proportioning valve in. I need to go bleeding steps again - did not turn out as expected. Both cars I had are 4 wheel drum. So not sure if some of the issues I'm seeing are related to disk/drum MC behaving differently.
Never changed a MC but know you are suppose to bench bleed first. Put MC in a vise and begun pushing plunger in. Front bowl was getting fluid coming out of port pretty good. The back was not even pushing fluid hard enough to get it thru tube and back into bowl. Tried this for awhile and ended up getting frustrated.
I looked at instructions for my Mityvac (hand lever type) which has instructions for bleeding MC. Did that and was able to suck fluid thru and did not see any bubbles in fluid coming in thru the tubes. Before mounting MC I did not check plunger to see if could only be depressed a small amount as instructions indicated (duh moment).
After mounting MC proceeded to bleed rear brakes with mityvac and what was typically an easy job before (could drain a bowl quickly if not careful) was not able to get any fluid to right rear. I know its getting fluid to them though. I left the bleeder open and fluid was dripping out. Tried on left rear was able to draw fluid but not as much came thru as I've seen in the past. Doubled checked and I had the proportioning valve in full open position. Tried right front and it worked good.
In any case - I need to redo them to a point I feel comfortable. Engine not in car so can't test them but not confident that I got all the air out.
I'm going to take MC off and rebleed and I'm also going to get some speed bleeders and try that route.
Couple of questions:
1) When bench bleeding is it normal that fronts bleed out quicker than the rears?
2) How many times should have to plunge to get air out?
3) Writes up I've seen called for waiting 15 seconds if staggered. Are disk/drum MC considered staggered? I did not do that - not very patient.
4) Do I need to plug one port and do one at a time?
5) Couple of methods I've seen for bleeding using the tube approach. One says to pinch tube as plunger is returning. The other says nothing about this. Which one is correct?
6) Any way to test with engine out (no vacuum to booster)?
Appreciate any suggestions. thanks
Never changed a MC but know you are suppose to bench bleed first. Put MC in a vise and begun pushing plunger in. Front bowl was getting fluid coming out of port pretty good. The back was not even pushing fluid hard enough to get it thru tube and back into bowl. Tried this for awhile and ended up getting frustrated.
I looked at instructions for my Mityvac (hand lever type) which has instructions for bleeding MC. Did that and was able to suck fluid thru and did not see any bubbles in fluid coming in thru the tubes. Before mounting MC I did not check plunger to see if could only be depressed a small amount as instructions indicated (duh moment).
After mounting MC proceeded to bleed rear brakes with mityvac and what was typically an easy job before (could drain a bowl quickly if not careful) was not able to get any fluid to right rear. I know its getting fluid to them though. I left the bleeder open and fluid was dripping out. Tried on left rear was able to draw fluid but not as much came thru as I've seen in the past. Doubled checked and I had the proportioning valve in full open position. Tried right front and it worked good.
In any case - I need to redo them to a point I feel comfortable. Engine not in car so can't test them but not confident that I got all the air out.
I'm going to take MC off and rebleed and I'm also going to get some speed bleeders and try that route.
Couple of questions:
1) When bench bleeding is it normal that fronts bleed out quicker than the rears?
2) How many times should have to plunge to get air out?
3) Writes up I've seen called for waiting 15 seconds if staggered. Are disk/drum MC considered staggered? I did not do that - not very patient.
4) Do I need to plug one port and do one at a time?
5) Couple of methods I've seen for bleeding using the tube approach. One says to pinch tube as plunger is returning. The other says nothing about this. Which one is correct?
6) Any way to test with engine out (no vacuum to booster)?
Appreciate any suggestions. thanks
