ok let me try this again

[John H]

01 4x4 ranger..does it have a replaceable proportioning valve?
I know its supposed to be 80% pressure to front brakes and 20% to the rear, my rears feel like they are getting the 80% and my fronts are getting 20%. Is it possible that something is reversed in my system or is something else wrong? with the rears disengaged the pedal has more travel, and the fronts have a hard time stopping the truck. with the rears hooked up I barely touch the pedal and I stop easy, If I get aggressive on the pedal the rears will lock up or try too. Also I go through rear brakes more frequently than front pads

 

[Ranger Dave (B25)]

I can't find a p/n for one, so maybe not.

ETA: Found this:

http://www.ebay.com/itm/NOS-1984-20...a331d3e&pid=100005&rk=1&rkt=6&sd=362017199805

 

[Mark_88]

Sounds more like a matter of possible Master Cylinder is on the way out or adjustments need to be made.

The rear brakes on older models could be adjusted up to the point where they engage faster than they should and I've done this myself a few times.

Other than that...is everything new as in front rotors and pads and rear drums and shoes?

If it is all new and recently installed/adjusted, I would try to back the rear brakes off a few notches

 

[black_demon69]

drums could also be out of round

 

[JoshT]

IIRC by 01 they had dropped the proportioning valve and the ABS module handled that function.

What do you mean by "with the rears disengaged"? Only way I am aware of to disengage the rears is by opening the system. If you did that you probably need to bleed the entire system which is made more difficult by the ABS module. Even if you didn't open the system, you may be due for some new hoses and bleeding the system. Both are needed as the system ages and it's 16 years old at this point.

 

[John H]

The adjusters are on the wrong side so they weren't opening, they were turned all the way in. The shoes weren't touching the drums when I'd press the pedal, that's why I say they were disabled. The fronts were doing all the work but they didn't seem to be stopping very well, lords of pedal travel and hardly no stopping power

 

[adsm08]

The adjusters are on the wrong side so they weren't opening, they were turned all the way in. The shoes weren't touching the drums when I'd press the pedal

This is your entire problem.

Brake proportioning is less about sending hydraulic pressure/braking power to a given wheel than it is about keeping the vehicle going in a straight line when the brakes are applied. If the front axle were to engage right away when you hit the pedal the rear would get squirrley.

Remember the time when you were a kid and you wore out the rear brakes on your bike, so you slammed the fronts at the bottom of that hill and flipped your ass end over end off the bike, hit the bridge with your face and landed in the creek? No? That was just me? Ok, anyway, that's what happens to a car when you engage the front brakes full force first. The front tries to stop, the rear wants to keep going, and bad things happen.

If you engage the rear brakes first then the fronts the rear starts slowing down first as the front continues to try and pull away and you get a straight line. You've never seen a dog's leash crumple up while the owner was standing still and the dog pulling it have you?

So in a brake system there is a valve some where, sometimes it is in-line, but more commonly it is part of the master cylinder or ABS unit, that basically bypasses or at least tones down the circuit for the front brakes until the rear starts to build pressure. Then it allows the front to pressure up and engage the front brakes If your shoes are adjusted the whole way in then they will never push on the drums enough to create the kind of feedback needed, and your front brakes won't work at their potential because they aren't given as much pressure as they should get. And since you are pushing out on the wheel cylinder pistons really far trying to make that contact you get a ton of pedal travel because you have to go farther with the piston in the master cylinder to go farther with the pistons in the wheel cylinders.


If you want to accurately see what your front brakes are delivering by themselves you pretty much have to find a piece to plug off the brake lines so that the rear circuit can build that pressure without moving the shoes. You will see that they are working. You might also see your truck spin a few times.