Do you have your P-Valve on the front brakes?
All the vehicles that I’ve had have the MC outlet to the front brakes closes to the fire wall.
Like mention above hose does expand a lot. Get rid of the hose and use steel or stainless tube.
Good Luck
Cant get rear disc brakes to lock
- Thread starter Groundhog
- Start date
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Do you have your P-Valve on the front brakes?
All the vehicles that I’ve had have the MC outlet to the front brakes closes to the fire wall.
Like mention above hose does expand a lot. Get rid of the hose and use steel or stainless tube.
Good Luck
- Thread starter
- #22
The port closest to the firewall has the p-valve and is feeding the rear circuit.
I went through a whole host of brake problems and what finally worked for me was an fj60 master and booster with a proportioning and residual valve on the rears with steel tubing throughout. The 2lbs residual valve did the trick to give it the "out of the factory" feel. Good luck.
Poser said:
What I'm trying to refer to is verify the pressure to the brakes. I'd totally agree with earlier statement on soft hoses vs SS hoses. If its possible I'd recommend switching to hard lines/SS flex lines from soft rubber lines, but it's not always feasible. What I've done in the past (not FJ, I'd probably face some work on this topic coming spring when will be working on my brakes) is to check the pressure on the ports of Master Cylinder and then verified the numbers on the Calipers. My old mechanic used to have a cool pressure tester I borrowed from him. But this was around 15 years ago. I was thinking 40-series should not be complicated from brakes perspective as it doesn't have brake assist devices like modern cars do.
Sorry if I wasn't clear from the beginning.
Reading the first post over again I realized that His proportioning valve fully open and he still didn't get rear brakes to lock, so issue may not be in the valve.
rears are supposed to lock up first. that way you still have contol of your steer wheels
Common misconception. When a vehicle, whether it's a motorcycle, car, truck, or even bicycle brake the weight transfer moves to the front of the vehicle leaving less resistance on the rear wheels. This is best exemplified when you go biking and hit the rear brakes. What happens... you skid. When you hit the front brake you usually end up going over the handle bars.
You can take a look at this link for more info: National Agenda for Motorcycle Safety
Basically, the front and rears need to be working together to provide optimum braking but the fronts need to provide the primary braking resistance. That's why front brakes always need to be changed before rears.
whats the deal said:
Usually, but not the case on some of the new VW Audi cars.
The bias is set up differently to help prevent nose dive. I went through rear brakes in 20k and my fronts are still good at 80k.
Hen you wash the car, the rear wheels also have all of the brake dust versus the fronts, which is inverse of almost all modern cars.
i'm not saying the fronts aren't supposed to brake hard, they're just not supposed to lock up first.