2nd Gen Non-Engine/Transmission Brakes don't have power at less than 15 mph. Does removing a fuse 'fix' this?

[raxley]

I heard or read that when the ABS 'goes out' on those trucks that have it, that the brakes work badly. My truck has increasingly had this problem, which goes away from about 10-15 mph and up. It's getting a little worrisome at stoplights, etc. I can press about as hard as I can, but the brakes work poorly, it seems like the power assist is gone, sort of like when truck is not running and you are trying to turn the steering wheel.
I heard that if you remove some fuse, that this problem goes away.
Is this correct, and does anybody know which fuse it is?

 

[NIsaacs]

I would check for a vacuum leak.

Nick

 

[GAmes]

You have vacuum assist brakes on the '94. There isn't a fuse for that. Disconnecting the ABS won't improve braking, nor make it worse for that matter. Troubleshooting the brake system should be covered in the factory service manual, and I'm sure that some searching of the forum will grant you some wisdom.

 

[fest3er]

Does the '94 have rear-wheel anti-lock brakes? If so, and the sensor is clogged or the twisted pair wiring is somewhat defective, the voltage the CAB (Controller, Anti-lock Brake) gets from the sensor could be dropping below a certain minimum threshold. This would cause the CAB to think the rear axle has stopped turning and engage ABS. And if that '94 is anything like my '98, when RWAL engages, at least 50% of all braking power vanishes.

raxley, have you noticed that full brake power returns rather suddenly at 3-5 MPH? Pull the sensor on the rear axle and make sure it's clean and in good shape. Check the wiring and connectors on the twisted pair cable going from the sensor to the CAB. Check the connector(s) on the CAB. Make sure all is clean.

 

[fest3er]

Does the '94 have rear-wheel anti-lock brakes? If so, and the sensor is clogged or the twisted pair wiring is somewhat defective, the voltage the CAB (Controller, Anti-lock Brake) gets from the sensor could be dropping below a certain minimum threshold. This would cause the CAB to think the rear axle has stopped turning and engage ABS. And if that '94 is anything like my '98, when RWAL engages, at least 50% of all braking power vanishes.

raxley, have you noticed that full brake power returns rather suddenly at 3-5 MPH? Pull the sensor on the rear axle and make sure it's clean and in good shape. Check the wiring and connectors on the twisted pair cable going from the sensor to the CAB. Check the connector(s) on the CAB. Make sure all is clean.

 

[GAmes]

I really doubt that a faulty ABS sensor could cause your problem, normally they just trigger lights on the dash. But just in case, simply pulling the ABS fuse or unplugging the ABS module will take it entirely out of the system. If braking improves, you have found your culprit.

 

[Road Dog]

I had the issue with the rear wheel ABS on my 98. As I slowed down to 10mph the speedo fell to zero (same sensor in 98) and the ABS would release the brake pressure because it thought the rear wheels were locked. Stupid system. I seated the sensor (sometimes they're installed wrong) and cleaned the connector. That fixed the problem. Removing the fuse will disable the system so it's an easy test.

The sensor is a hall-effect sensor and detects the teeth from a ring on the carrier. Pulses are generated and the timing can be used to calculate the speed and whether the wheels are locked.