Brake and Speedo problem with 1994 Explorer

[oc2aa]

I am a newbie but i searched alot for these answers before posting so please excuse if there are answers somewhere.
My biggest problem is that my brakes recently started occasionally pushing back at me. When i press the brake down, the brake pushes back and the car shutters to a stop. I thought maybe this was an ABS problem so I checked the front wheel speed sensors and they were both fine. My ABS light is on but it has been on for over four years straight. Any suggestions?My truck is 2WD, is there a speed sensor on the rear axle?

My next problem is that my speedometer is innacurate. My tires are the correct size. My speedometer reads about 80% of the actual speed I am going. If driving 50 MPH it reads 40, if i am going 75 it reads 60. This has also been going on ever since i got the truck about four years ago. ANy advice would be great. Thanks and I look forward to being addicted to this forum.

 

[ActionJackson]

could be a bad abs module. im not sure if you can unplug the module from the computer, but if you can give that a shot see if it stops the pedal pushing back. the down side is youll have to deal with the abs light and you wont have anti lock brakes, but the brakes will still function normaly. as for the speedo problem i dont know