that brake fluid looks nasty
Upgraded to fj60 disc front and not enough stopping power? (1 Viewer)
- Thread starter Jespervangfalkenberg
- Start date
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- Thread starter
- #22
the last picture is not from my car... it was just to show the valve I dont have fitted my vehicle!
71FJnick
SILVER Star
If you don't have a prop valve with disk brakes and are using a master cylinder from a dual drum setup, I believe you will push the same pressure and volume of fluid to the front and rear brakes (or whatever bias was built into the original drum/drum setup).
When you put disks on the front, the piston is larger in the caliper so the same volume of fluid provides less pressure on the brakes.
A proportioning valve will bias the pressure so that more volume goes to the front and less to the rear ( to be honest this may be pressure but the idea is the same, you can tune breaking force as a function of pressure or volume from front to rear).
Typically a sign of poor bias is the rear brakes locking before the front. It sounds like you don't have this problem, but this is information anyway.
-nick
When you put disks on the front, the piston is larger in the caliper so the same volume of fluid provides less pressure on the brakes.
A proportioning valve will bias the pressure so that more volume goes to the front and less to the rear ( to be honest this may be pressure but the idea is the same, you can tune breaking force as a function of pressure or volume from front to rear).
Typically a sign of poor bias is the rear brakes locking before the front. It sounds like you don't have this problem, but this is information anyway.
-nick
- Thread starter
- #24
Yes - I am starting to believe it is - in some way - the problem, not enough pressure to the frontend!
the proportioning valve is needed to dial the rear brake force down
this is separate from the residual valves in the master cylinder - you should not have a residual valve in the circuit to the disks
this is separate from the residual valves in the master cylinder - you should not have a residual valve in the circuit to the disks
TJ96TLC
SILVER Star
Fighting the same issues. Have a working OEM brake booster on my 71. Upgraded the front brakes to 60 series, stock drums on rear. What Master Cylinder would drop in and work without a proportioning valve? I am think a 60 series. Thoughts?
