93 Rear ABS system fix, No rear brakes on ice at low speed

[Crazy Wayne]

Yes the problems of the rear ABS system.

The ABS unit tends to dump too much brake fluid pressure into the accumulator.

When backing the vehicle and applying the brakes the pressure is dumped into the accumulator.

This happens at such a low pressure in the accumulator phase that the rear adjusters will not function.

So you basically end up with rear brakes that are so far out of adjustment that your brake pedal goes to the floor boards. And you're breaking ability at all speeds from the rear axle is decreased.

And when attempting to come to a stop at low speeds on icy roads.

The engine is allowed to produce power through the rear wheels and push the front axle forward with the front wheels locked up.

You can manually adjust the rear brakes which will cure the high speed braking issues.

But an icy road conditions at low speed you're at the mercy of the accumulator pressure.

The fix I've discovered is quite simple.

Above the driver side rear axle in the frame Channel.

You will find the ABS accumulator assembly.

By simply removing the aluminum cap at the forward end.

I suggest using a small pipe wrench or some large vise grips to hold the cast iron assembly as the bolts mounting it are quite small.

There is no brake fluid in this end of the assembly.

After removing the cap you should be able to pull out or catch the accumulator spring.

Do not push the brake pedal down while this cap is removed or the accumulator piston will be pushed out of the assembly.

By simply replacing the spring with a stiffer one.

This will give you a increase of brake pressure to the rear wheel cylinders when the ABS is functioning.

This will give you enough brake pressure to overcome the return Springs on the brake shoes.

And the automatic adjusters will be able to do their job.

When backing and applying the brakes because the brake shoes will be able to rock back and forth to ratchet the adjuster.

And when driving on ice or other extremely slippery surfaces you will have the ability to have some breaking from the rear axle and possibly locking them up.