Im just about fed up!!

[Black98Burb1500]

Ok so I drive a 1999 suburban k1500 lt with the 5.7 vortec. 5 months ago I got a wicked rod knock so I bought a 99 denali and swapped motors. Truck was running good for a few months and I wanted a smoother ride so I got new upper and lower control arms, tie rods, cv joints, hub and bearings idler and pitman arms, sway bar bushings and end links etc. Rebuilt the whole front end. I threw new rotors I had laying around on there also with a fresh set of pads. So I go to the local alignment shop for tire rotation and balance and alignment its been aligned now 3 times by 2 different shops I even replaced the calipers and brake hoses because it keeps pulling to the right. Also it almost feels like its got some brake drag. It doesn't when its in the air and I spin the wheels just sometimes during deceleration. I dont know what else it could be I was thinking maybe master cylinder going bad perhaps the proportioning valve issue there's a tsb for. I have had a hissing behind my dash that I haven't been able to figure out for awhile. Any help would be greatly appreciated I just want to enjoy my truck that I've spent hours blood sweat and soon to be tears over but I can't when it tries to drag me off the road all the time. Thanks in advance I've read alot of the wisdom that comes into this forum and thought it would be worth a shot.

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[JWOK]

A couple questions to help pinpoint your problem:
1. Was this an issue at all before you replaced all the front end components?
2. Does the pull happen all the time while driving or just when braking?
3. Have you tried swapping front tires side to side?
4. Did you get the specs that the alignment was set to? Was there a caster split from side to side?

There are several things that can cause a pull and it looks like you eliminated most of the potential brake parts that could do this. Tires can cause it as well as not having enough caster after alignment. Most alignment shops anymore don’t even understand what they are doing to the vehicle regarding camber/caster/toe, they just adjust what the computer tells them to until they are within the acceptable range.

 

[Dropped88]

Did it pull after the new parts when you drove to the alignment shop?

Also you mentioned rotation you could also have a tire causing a pull.

Did they give you a print out of before/after alignment?

 

[JWOK]

Also, master cyl problems shouldn’t cause a pull as it applies pressure from one piston to both calipers at the same time, no way for the MC to apply more pressure to one wheel. The hissing behind the dash could likely be the brake booster going out, but that will not cause a pull. Unplug and cap the vacuum line to the booster from the intake and start the truck and see if the noise is gone. Cap the line from the intake or you may just hear that noise though. Don’t drive it with the vacuum line off.

 

[Supercharged111]

Sounds like it's time for a competent alignment shop. Alignments don't pay the bills, so most will just get it in the green and send you on your way.

 

[CKVortec]

good information already posted here, but wait... there's more!
if you have a pull under braking it could easily be from your rear brakes.
to test this take the front brakes out of the equation, when driving in a safe area/location pull the parking brake release and hold it so that the parking brake will not lock and lightly push the pedal. This will apply only the rear brakes and if your truck pulls... fix or readjust the rear brakes.
Just be aware that if your parking brake cables are in poor condition they may not release properly and you could end up with burned up/warped rear brakes unless you do something about it.
As stated above, the master cylinder won't cause a pull and neither will the brake booster that you hear hissing under the dash.
if your truck goes straight until you hit the brakes it is either one brake is not grabbing as it should (front or rear) or something is shifting in the steering/suspension when you hit the brakes. Since you replaced so much it's not likely to be front end parts.
Post up the before and after numbers from your alignment printout, if you didn't get one when you had the alignment done you got ripped off.

 

[JWOK]

good information already posted here, but wait... there's more!
if you have a pull under braking it could easily be from your rear brakes.
to test this take the front brakes out of the equation, when driving in a safe area/location pull the parking brake release and hold it so that the parking brake will not lock and lightly push the pedal. This will apply only the rear brakes and if your truck pulls... fix or readjust the rear brakes.
Just be aware that if your parking brake cables are in poor condition they may not release properly and you could end up with burned up/warped rear brakes unless you do something about it.
As stated above, the master cylinder won't cause a pull and neither will the brake booster that you hear hissing under the dash.
if your truck goes straight until you hit the brakes it is either one brake is not grabbing as it should (front or rear) or something is shifting in the steering/suspension when you hit the brakes. Since you replaced so much it's not likely to be front end parts.
Post up the before and after numbers from your alignment printout, if you didn't get one when you had the alignment done you got ripped off.

Good points! Many possible causes of a pull, just start with the most common/easiest to check and work your way through.

 

[Black98Burb1500]

A couple questions to help pinpoint your problem:
1. Was this an issue at all before you replaced all the front end components?
2. Does the pull happen all the time while driving or just when braking?
3. Have you tried swapping front tires side to side?
4. Did you get the specs that the alignment was set to? Was there a caster split from side to side?

There are several things that can cause a pull and it looks like you eliminated most of the potential brake parts that could do this. Tires can cause it as well as not having enough caster after alignment. Most alignment shops anymore don’t even understand what they are doing to the vehicle regarding camber/caster/toe, they just adjust what the computer tells them to until they are within the acceptable range.

The tires have been rotated and balanced i dont know where they were moved from though I will try swapping front tires, it did not happen this severe but it did pull some before and the brake drag is worst on deceleration and somewhat on acceleration when the brakes are applied the pull isn't as bad and the brake work just fine. I do have the spec sheets all 3 of them there is .3° difference on caster on the latest sheet that is what you meen by a split caster left is 5.0° and right is 4.7° which isn't in the recommendations for specified range looks like im going back for a 4th alignment in the morning. If you could give me some advice on what to tell them it would help me out a lot. I'm getting ok at working on my truck but getting these shops to do right by my truck has been a different story. Thanks for the reply

 

[evilunclegrimace]

Before you spend any more money on alignments get rid of those old rubber brake lines and bleed the front brakes, It is possible that you have a partially collapsed line that causes the truck to pull under pressure. Your left line could not be flowing the same as the right due to a restriction and that is one possible cause for the truck to pull to the right.

 

[JWOK]

Caster being different from side to side (split) is what I meant, but they have it backwards from what it needs to be. Having the right side a little higher makes most vehicles track straight on the average road due to road crown (most roads are higher in the center and slope to the ditch which introduces a slight right drift in most vehicles unless they have a slightly higher caster on the passenger side). Combining a higher caster on the left with the average road crown will cause a pull to the right. If it is a hard pull, I would still try swapping front tires side to side and see whether that makes a difference and have the alignment changed. Caster in the 4.5-5.0 range is pretty good as long as the split is favoring the correct side. That is back to the comment I made that most shops really don't know what they are doing with the alignment, they are just adjusting what the computer tells them to do until it gives them a green reading. Unfortunately that only puts you into an "acceptable range" and not necessarily what it needs to be for proper tire wear, tracking, or handling. I would ask them to make sure you have about 1/4 degree positive camber on both sides and the caster on the passenger side needs to be about 1/2 degree higher than the driver side.