Brake pressure differential switch Q's

[mattman9696]

What exactly does the brake pressure differential switch do?

Does it affect the braking pressures any? Does it have any effect on the brakes when you are trying to bleed the rears?

I am confused by what I am reading about this switch and by the fact they are extremely hard to find for my vehicle (1984 BII).

Thanks.

 

[BRUTUS_T_HOG]

it detects a brake failure and alerts the driver by lighting the brake light.

if either the front or rear brakes have a pressure loss the piston inside will move to one side of the other.

if you don't bleed the brakes this valve will move and light the light up. to center it you just have to bleed all 4 brakes

 

[mattman9696]

If the valve is not centered will it have any effect on brake bleeding? Does it act like a real proportioning valve?

I am having a hard time bleeding my rears (not much fluid coming through with a pressure bleeder). Some info on this site says it may and some says it doesn't. I'm confused and more so since I can't find a replacement for this part.

 

[BRUTUS_T_HOG]

i don't know if rangers use a combination valve.. it might

try using an assistant to bleed the brakes manually. if that doesn't work then you might have something plugged up

 

[adsm08]

I think the Rangers used a combo valve. The other problem you are probably running up against is where you are looking. Due to the nature of things like that a lot of brake parts (valves in particular) where never released to the aftermarket and are dealership only items. Did you try the dealer?