QuestionQUESTION: I have a 2000 Ford F150 the ABS light is on and stays on, when you press the break pedel( soft,med, hard) it dont matter, the left rear always locks up,I've checked the clearence between shoes and drum on both sides 'they are the same its just the left rear that locks up any thoughts.....plese.... its a2000 Ford F150 2wd,4.6l v6 a/t
ANSWER: Hello
I am assuming that you do not have the diagnostic codes for the ABS.
To get the trouble codes, you need to find the RWABS connector under the dash to the right of passenger footwell. It is a black connector with a red wire on one end and a Black/ Orange wire on the other. Drive the vehicle until the ABS light comes on, then park vehicle but leave it running. ABS light must be on to access codes. Disconnect the black connector and , using a piece of wire (jumper), connect the Black/ Orange wire to a good ground.
ABS light will start flashing. It will flash with slow breaks to count the tens ( flash..........flash........flash) =30, then it will flash quick flashes for the ones ( flash..flash..flash..flash)=4 30+4= 34 this is a code 34
the codes should repeat themselves. When you are done, shut truck off and reconnect the connector.
The most common failure is the sensor in the rear differential. It is on the top of the Diff and has 2 twisted wires to it. Unplug the sensor and measure the resistance between the 2 terminals of the sensor. (900-2500 ohms is acceptable) replace the sensor if you get anything else. It is a simple replacement. simply remove the bolt and slide sensor out. clean the hole and reinstall.
Check the wiring as well, the insulation may have been rubbed through or wires broken.
As for the brakes locking up: are brake shoes on both sides clean and even? is the axle seal, or wheel cylinder leaking? Are the drums both the same size, and do both brakes move when pedal is applied? Remove the drums on one side at a time and have someone slowly depress the brake pedal . you should see the shoes move. Is there a leading and secondary shoe, and is the leading shoe towards the front?
Let me know what you find please.
---------- FOLLOW-UP ----------
QUESTION: Thank you. I replaced the sensor and it turned out the abs light,and i pulled the abs code like you said and the way it flashed, it seemed like 16, it flashed 16 quick flashes and on the 16th was not as quick, and Yes it repeted the code,now the light is out but the lock up is still there, its like when you step on the breaks all the fluid and pressure is centered on that left rear wheel,there is a valve under the master cylender, is that the paporsion valve, and whateles could be my problem THANK YOU.
AnswerI'm glad you repaired your ABS. A code 16 is "All Good" code.
The proportioning valve under the master cylinder is just that. It regulates the amount of pressure applied the the rear wheels so that braking is even.
Because it regulates both of the rear brakes and there is only 1 brake line to the rear axle, that is not your problem.
Jack up your rear end and put truck in neutral. have someone hold brake pedal down and try to turn the rear wheels. If right side turns easily, you can be sure that the brake pressure is not going to that wheel or not causing the shoes to move enough.
If the right wheel cannot be turned, I would concentrate on the left side brakes. Recheck what was in the last memo.
