Brake Pull

it my be the Proportioning Valve. look at the brake lines from master or abs. they will all go into this. it sounds like it it's working.

There is a tsb on this, what is the build date? It is on the door jamb sticker.

TSB ref # 03-19-10

Tonight, I bled both sides again, hooked up to the computer and let it run through a bleed test to try and reset the ABS valves and rechecked the slides n both calipers. Both were working fine. Since the pull is still going to the right, I feel it is the left caliper so I checked to make sure both pistons in the left caliper were coming out equally and they were.

Still a pull.

I plan on replacing AGAIN the left caliper tomorrow. I did not show any codes reference the ABS hydraulic unit.

I don't know if the steering damper or track bar might have something to do with it??? Any ideas?

Build Date is 03/02

That tsb has a procedure for troublehooting. I don't see your build date listed in a section that refers to particlar solutions. However, run these tests,post results and we can go from there:


Road Test A: Straight Road Driving

Maintain a steady speed of about 50-55 MPH (80-88 km/h) DO NOT BRAKE.
Is the clear vision OK?
Does the vehicle drift? If yes, which way does it drift?
Road Test B: Low Speed Braking

Road test B should be performed on a road with no crown.

Make a series of stops (10-15) from speeds of 35-40 MPH (56-64 km/h) with light to moderate braking.
Does the vehicle pull? If yes, which way does it pull?


Road Test C: High Speed Braking

Maintain a speed of about 55-65 MPH (88-104 km/h) in a safe clear area. While firmly holding the steering wheel from rotating, apply the brakes moderately hard, but not to the point of engaging the Antilock Brake System (ABS).
Does the vehicle pull? If yes, which way does it pull?

5/15/07
Obtained another caliper, but after having checked both calipers and they appeared to be working properly, i am reluctant to replace it just because that is what you should do on th esymptom. The TSB test failed, but their answer is to replace the caliper assemblies which I already did.

Trying to think outside the box, I thought I would flip flop the front tires with each other (can't diagonally cross because of rim issues and would have to remount.

Took it out for test drive and braking was straight!!. Road conditions were changed because it was raining.

Drove home and 20 miles later, the pull started again.

05/16/07
Drove to work in the morning. Dry roads and was braking straight again. Within 11 miles, it was pulling right again.

After work, drove home and braked straight all the way home. (it was raining all the way.)

***Researching on the internet at lunch break, I read a year old post on a different forum I came across which they guy resolved the problem when the mechanic he finally took it to replaced the right wheel hub that was clicking as well as the lower ball joint.

I had checked my ball joints and they are tight. I do get a click on the right side, but it's coming from the locking hub.

My question to all is, trhinking outside the box, could it be the sealed wheel hub assembly causing the problem? Maybe when it heats up? Hopefully tomorrow will be dry so I can see if it remains braking straight.

I really wish I could tell you what the magic bullet is. From the research I have done on it, these trucks have charatoristics of pulling. It just isn't logical to me. Having said that and seeing so many engineering disasters I could see how it could happen. The only thing I can provide is the recommended testing procedures based on the above tests results.

I have a F350 crew diesel and had the same problems. I took my truck in on many occasions to the dealer and none of them coud fix it, just cost me money. I tore down the brakes myself and found two issues. First ball joints were shot, so I replaced them. Second, The brake caliper slider pins on one side were very stiff and corroded. I replaced the entire brake caliper braket and slide pins. Wow, no more pull, straight as an arrow. Im so glad I paid money to proffesional mechanics to not find these simple issues.