Rear Brake Level Sensor Brake Valve With ABS (1988-1991 Camry Station Wagons)

toyota
camry

#1

1991 Camry Station Wagon LE V-6 (with ABS, with 4-wheel disc brakes)

My vehicle was factory equipped with a rear level (height) sensor that automatically raises or lowers braking system pressures to the rear wheels, dependent on vehicle loading. The OEM part number of the level sensor/valve is 47900-32030. Toyota no longer sells this part.

Due to corrosion damage, I am in the midst of replacing all of the steel brake and fuel lines on the car with corrosion resistant NiCopp tubing. Unfortunately, that level sensor/valve (part number 47900-32030) which interconnects with the rear brake tubes, is terribly rusted and I am not sure if I will be able to re-use the level sensor due to the amount of external corrosion.

If I cannot re-use the level sensor/valve, I wonder if it is permissible to simply leave the device out of the brake circuit because the only consequence will be that brake pressures to the rear will not be increased to the design value when loading in the rear rises and vice versa, that is when the car is only lightly loaded, brake pressures to the rear brakes will be a little higher than the design target. I understand that one consequence of the former is that the FRONT brakes could be more subject to more fade in certain, I think exceptional, circumstances. In the latter scenario, with rear brake pressures higher than the design target (under light loads) that of course creates the “potential” for rear wheel lock-up. However, this vehicle is equipped with ABS so wheel lock is impossible in any event. All in all, and to conclude, my understanding of how the brakes operate on this car is that although removing the level sensor/valve will cause stopping distances, potential for fade, and premature wear all to depart from optimal design values, the vehicle would not become unsafe to drive under normal conditions.

Does anyone have any technical advice concerning this?


#2

Rear lockup with ABS is NOT impossible, trust me, I have experienced it first hand. ABS is looking for a differential in the wheel speeds, but if both wheels lock up at the same time, they will lock up.

Unless you were very bad about brake fluid changes in your car, the insides of the proportioning valve are probably corrosion free. If you can work the lever on the outside, I would just lubricate the lever and reuse it.

BTW, Toyota did not make this part so you may be able to find a proportioning from another vehicle that fits, provided that you can swap out the linkage. Nissan used these on their pickup trucks. Almost all small trucks and vans use these in some form or other.


#3

My 1990 Toyota Pick-up had one of these as well. I’m sure there are other Toyota models that may have used these, too.


#4

@TechnicalKevin

I agree with @keith

As long as the lever moves and the valve isn’t leaking brake fluid, you should be fine, even if it doesn’t look nice

A bit of advice . . . spray the fittings with penetrant and let it work in overnight. Then use line wrenches, NOT open end wrenches