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Brake Bleeding

polack77

New Member
Joined
May 20, 2025
Messages
30
Changed the master cylinder and new lines to the HBlock on my 75 but having a hard time getting the brakes to bleed. Bought a manual pump and when I release it seems that the fluid in the master cylinder should go down but I went through about 10 procedures on the pump and still has the same amount of fluid.

I don’t see any open lines or anything is the a way to pressure test the lines? I don’t see any fluid leaking anywhere
 

ntsqd

heratic car camper
Joined
Jan 30, 2005
Messages
5,953
Loc.
Upper SoKA
Did you bench bleed the m/c before you put it on or before you connected the vehicle's plumbing to it?
 

B RON CO

Contributor
Bronco Guru
Joined
Jun 29, 2016
Messages
2,484
Loc.
Statesville, NC
Hi, did you compare the depth of the holes where the push rod goes in the master cylinders? Most new master cylinders come with plastic plugs which makes bench bleeding easy. Good luck
 
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polack77

New Member
Joined
May 20, 2025
Messages
30
The new push rod was the same size as the one I took out. I can push in the brake and see the fluid in master cylinder bubble some.
I know fluid is coming out of the master cylinder cause the new line to the bigger reservoir section on the master cylinder was leaking a little but I tightened it up and it quit.

I did not bench bleed the m/c, just took the old one off and put the new on. then added new lines to the H Block. I did take the H Block completely off and inspected it.
 
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polack77

New Member
Joined
May 20, 2025
Messages
30
Looks like I need to bench bleed the new m/c.
After watching a few videos, it doesn't look to hard. I
 

73azbronco

Contributor
Bronco Guru
Joined
Nov 11, 2007
Messages
8,778
doesn't look to hard... Take your time use a master cylinder bleed tube/kit or make one yourself,
 

ntsqd

heratic car camper
Joined
Jan 30, 2005
Messages
5,953
Loc.
Upper SoKA
Can do it in-place, don't need to remove it from the truck. If you have a vacuum booster I'd suggest removing the check valve to make the bleeding easier.
 

SteveL

Huge chevy guy
Joined
Jun 24, 2001
Messages
11,969
Loc.
Hawthorne ca
Stop at the local ap store and get a cheap bench bleed kit. It's just a couple plastic line adapters and 2 short lines that clip to the top of the mc. Then you just jump in and pump the pedal.
 
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