Bleed brakes - 100% new system
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Staging Lane
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Bleed brakes - 100% new system
I know, another brake bleeding question but I cannot seem to find an answer to my question. I have a 1972 Chevelle, LS3/T56 setup, and have nearly completed a complete rebuild from the ground up. The ENTIRE brake system is brand new never used, never bled, never seen brake fluid at all. It has a standard Chevy MC, and C5 disks on all 4 wheels. In researching how to properly bleed, the consensus was that I would have to:
1) Bench bleed the MC
2) Open the bleeder on RR caliper gravity bleed
3) Open bleeder on RL gravity bleed
4) Open bleeder on RF gravity bleed
5) Open bleeder on LF gravity bleed
6) Then pressure bleed from each caliper in the same order.
My questions are They say to bench bleed your MC because if you dont, then you push air into the hoses and lines down the line. Guess what? They are all full of air already so is bench bleeding necessary on a brand new, never used, just built car? Second, many say to gravity feed each caliper first, but from what I know about how fluid flows through hoses would that not lead to air bubbles being trapped at the top of all those pigtails that come off the MC? Or anywhere else for that matter? Seems to me that in order to get all that air out of the pigtails, the fluid would have to be pulled or pushed through the system rather quickly. Any opinions?
Second I have speed bleeders on the system. I also have a Mityvac. I have heard that the two do not play nice together, but cannot verify. I guess my questions are what is the best way to bleed a brand new, never used brake system for the first time (with speed bleeders) considering the fact that EVERYTHING is dry?
FYI - I still have the stock bleeders, just in case...
Tom Ringlein
1) Bench bleed the MC
2) Open the bleeder on RR caliper gravity bleed
3) Open bleeder on RL gravity bleed
4) Open bleeder on RF gravity bleed
5) Open bleeder on LF gravity bleed
6) Then pressure bleed from each caliper in the same order.
My questions are They say to bench bleed your MC because if you dont, then you push air into the hoses and lines down the line. Guess what? They are all full of air already so is bench bleeding necessary on a brand new, never used, just built car? Second, many say to gravity feed each caliper first, but from what I know about how fluid flows through hoses would that not lead to air bubbles being trapped at the top of all those pigtails that come off the MC? Or anywhere else for that matter? Seems to me that in order to get all that air out of the pigtails, the fluid would have to be pulled or pushed through the system rather quickly. Any opinions?
Second I have speed bleeders on the system. I also have a Mityvac. I have heard that the two do not play nice together, but cannot verify. I guess my questions are what is the best way to bleed a brand new, never used brake system for the first time (with speed bleeders) considering the fact that EVERYTHING is dry?
FYI - I still have the stock bleeders, just in case...
Tom Ringlein
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Bench bleeding is the right first step. In a lot of cars the master will sit inclined at ride height which can trap air in the bore that will never bleed out. That being said "bench bleeding" can be done on car and is the way I do it, the trick is to level the master by jacking the car. Hook up your recirc tubes and with slow long strokes of the pedal(all the way down-all the way up) you'll be done in five minutes. Gravity bleeding an empty system is more like priming and replaces about 95% of the air with fluid. Then you can either finish with the mityvac or have a helper with the pump and dump. Cant comment on the speed bleeders as I have never used them.
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Yea, that is more or less what I was thinking. I wanted to jack the rear up about 10-12" and level out the MC for a bench bleed while on the car. Was not sure though, becuase when I do this, the car will be fresh out of the body shop with a brand new show quality paint job. Underside of the hood will be detailed - so I did not want to get too happy with the pedal and spray brake fluid on my new paint. For that reason, I am researching now whether or not I want to do the DOT 3 or DOT 5 thing. Still on the fence. Think what I will do is bench bleed MC on the car, get the wife to use the Mityvac on each line while I keep the reservior full, then "pump and dump" pressure bleed at each caliper. Keep my fingers crossed for a nice, firm pedal. Somoething else, though. Once I bench bleed the MC - what will keep all that fluid from running out when I disconnect the bleeding kit and re-install the brake lines? I guess I would have to move fast and connect the line, have the bleeders open for gravity feed, and immediately start keeping the reservoir full as to not pull air into the system.
I have similiar questions about pressure bleeding the clutch MC/Slave. When I installed the transmission and new slave in 2008, I did not bench bleed the slave because I knew it would sit for 2 years while I was stationed overseas. Still working on that one.
TJR
I have similiar questions about pressure bleeding the clutch MC/Slave. When I installed the transmission and new slave in 2008, I did not bench bleed the slave because I knew it would sit for 2 years while I was stationed overseas. Still working on that one.
TJR
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Once I bench bleed the MC - what will keep all that fluid from running out when I disconnect the bleeding kit and re-install the brake lines? I guess I would have to move fast and connect the line, have the bleeders open for gravity feed, and immediately start keeping the reservoir full as to not pull air into the system.
TJR
TJR
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Kevin97SS - thanks for the tips. As much as I was not looking forward to this process, I am actually now looking forward to doing this stuff myself. But anything painted Viper Orange will certainly be covered with plastic and a towel or two for sure.
TJR
TJR