Disks pulling

[72Burro]

sorry for length.....
Before my hydro install, my brakes would pull hard to the driver side during panic stops.

When I did my hydro install, I got bored and pulled the front end, replaced all the bushings, tire rods, ball joints, steering, as well as all the brake hardware (calipers, rotors, bearings, lines)

Everything is back together and it still pulls hard to the drivers side(exaggerated w/ the pressure of Hboost) The driver side rotor is hotter too.
Here’s what I’ve done so far:
* ran 1 qrt of fluid thru the fronts for bleeding
*Switched pads on the front
*Switched tires
*Flow from R caliper bleeder looks the same as the left when cracked
*checked d-side caliper for sticking and pass-side for being frozen, both move freely.
* Tire pressure

I adjusted toe-in myself, but the alignment has not been checked.
I noticed the pass side appears to have more + Camber, it looks like this when the front end is jacked up ( \ | ) and i think my rear pass drum is farther out of spec than the drivers side since I'm always having to adjust it

I checked the two front tires, they are with in 1/16 of each other in size unmounted, but when I mount them on the truck, the drivers side tire some how ends up being about 5/16 inch shorter. I think this is from the camber issue..

Any ideas on what else to try or check? I’m taking it in tomorrow to be aligned, but I’m wondering if the camber issue could be causing it to pull or possibly the rear drum?

Thanks-

 

[mountain14er]

It could be the drums for sure but if you're going in for an allignment, wait and see if that helps before spending time on other stuff.

 

[broncnaz]

I think its kinda normal as mine does it during panic stops also. I think it has to do with the Drivers side brake line is shorter than the passenger side. During panic stops the drivers side will get pressure first and pull. One fix would be run a late model style proportioning valve with the brake lines split to each side so the proportioning valve equalixes the pressure between the sides and no more pulling. I thought about doing this but dont really want to run another brake line so I may just live with it. Also make sure the brake lines coming out of the junction block on the axle are not bend to much as the pass side line usually needs a pretty good bend to get it to fit. it could impede brake pressure if the inner dia. of the brake line has changed.

 

[72Burro]

more testing. I pulled both calipers and pushed the pistons in, then applied the brakes. the drivers side certinaly has more fluid moving through it.

Put the calipers back on, pumped up the brakes to and cracked the bleeders again, this time, nothing came out of the bleeder on the passenger side.. Checked, and checked again, either nothing comes out or just a very tiny amount. I can see nothing wrong with the drivers side set up.

So i'm thinking bad caliper (which is new) bad/kinked soft line (also new) or steel line off the axle (which I did not replace)

Any ideas on how to isolate any of these? Thanks

 

[bludorbronc]

You could get a brake pressure gauge ,like those sold by Stainless Steel Brake Co., and screw it into every bleeder screw one at a time and that will tell you exactly what the pressures are doing and better isolate the problem.

 

[BUCKETOBOLTS]

I'd say it is probably alignment related. If you a 1/2* or more difference in caster from side to side you will get a brake pull to the highest side.

 

[72Burro]

You could get a brake pressure gauge ,like those sold by Stainless Steel Brake Co., and screw it into every bleeder screw one at a time and that will tell you exactly what the pressures are doing and better isolate the problem.

Borrowed a pressure gauge this am. Turns out it's the caliper. I moved the L-caliper over just to double check. I hooked it up to the right side and used an old rotor and the pressure and pressure time were the same. As of this am i've made two trips to different Napas to pick up a new caliper, one had a nick on the sealing surface for the banjo bolt and the other leaked at the bleeder screw.. have to wait till Monday now. Thanks for the help.

 

[broncnaz]

You might have had some blockage in the line that is no longer there thats why the caliper works now. A bad caliper should still have high bleed pressure. The only way it wouldnt is if the seal was bad and the fuild was leaking out past the seal then you would have lower pressure on that caliper. You might want to hook it back up and try it again.

 

[SaddleUp]

Don't forget to be sure the rear brake drums are adjusted up properly. If one side is too loose it will cause it to pull to one side or the other and will feel like it is the front disks pulling. While your at it check for a leaking wheel bearing in the rear. That will also cause it to pull. Third check for bump steer in the frontend. (Get up on the bumper and jump up and down watching the steering wheel to see if it moves from side to side, If so then it is bump steer)

Keep in mind that the items listed are just the more common reasons for it to pull if front disks are on it. A pressure related problem such as what you are checking could also cause it so check these if that doesn't fix it.

 

[72Burro]

Got the alignement specs back
Toe is was fine,
L Camber .9, R Camber 1.0
L Caster -1.2, R Caster -1.0

Rear Toe: L -.24, R . 29

Rear seals are new, but removed rear drums and no oil, re-adjust rear brakes. Also replaced front R axle hardline (straighter w/less bends) Also, had my 300lb neighbor jump up and down on the front and the steering wheel stays straight.

Still pulls hard left.. I had someone drive it towards me at 50mph and hit the brakes. The front left tire looks like it's being pushed backwards (towards the rear axle) and the tire seem to flex sideways towards the left.

I'm stumped, all the brake hardware/software was new and I've had 3 calipers on the right side now.
The only other things I can think of is:
Caliper piston size not the same, but I measured the inside diameter of both sides with a micrometer and they are the same.

The rear L spring is sags about 2inches and the L front about 1/2 inch. when i put the front axle back in the arms were parallel so the lean on the drivers side is caused from the rear spings. Or the fact that the rear thrust is pointing towards the right.

Any other thoughs are appreciated.. Thanks

 

[73stallion]

You could get a brake pressure gauge ,like those sold by Stainless Steel Brake Co., and screw it into every bleeder screw one at a time and that will tell you exactly what the pressures are doing and better isolate the problem.

where exactly did you find that pressure guage? i just went to their website and i can't find one.?:?

 

[Pa PITT]

just change the calipor ...they are too cheep to worry about ....14.00 too 20.00 buck ....fords you can align with a tape and a carpenter square......Back when I ran my part store if the caliper had a metal piston in it ...it was most likely good but if it had a plastic piston it would stick ........

 

[Amac70]

you can get the brake pressure guages at s and w racing
www.swracecars.com

 

[bludorbronc]

Stainless Steel Brake Corp. Super Stop Brake Guage. Part #A1704

 

[72Burro]

Finally got the problem solved.. I'm still in a bit of disbelief here but it turned out to be a difference between the rotors. By chance I noticed the one rotor had a metric reading for min thickness and the other was in inches. I drove it to Napa so they could look and they confirmed although the same part number, that one was made in China and the other in Canada. So they got me another rotor for free, all i had to do was return the other as a defect. No more pulling.. Difference in metal quality I guess, we're not supposed to use two different types of friction pads so I guess the same can be true for rotors..

 

[Broncobowsher]

I was about ready to suggest swapping calipers (bleeders would be a bear, but worth it for an experiment.

Mine has a pull as well. I was thinking mine is calipers as one uses a metric bleeder, the other english.