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Pulling to the right under braking....


CD Smalley
10-05-2008, 12:32 PM
1997 C1500 2x4.

I just replaced everything on the front brakes since the truck has nearly 200K. I replaced the following:

rotors
calipers
front hoses
pads
bearings
seals
caliper bolts
hose bolts

Pretty much everything. My problem is that I have a slight pull to the right. It will turn the wheel from say 12 o'clock to 1 o'clock when braking without my hand on the wheel and will continue to pull to the right as I stop.

I have bled the system 3 times. No change in the braking pattern.

What am I missing guys?

CoolasIce
10-05-2008, 06:13 PM
Could be:

Different tires/air pressure
Worn out idler arm, control arm bushing, tie rod arm, or wheel bearing
Maybe rear brakes are grabbing unevenlyYou're just getting started.

CD Smalley
10-05-2008, 06:50 PM
It's done it with two different sets of tires, just had them replaced on Thursday. I did the brakes before that. I think I can rule out tires and tire pressures.

I am ruling our rear brakes since the steering wheel will turn when I brake.

An idler arm is a possibility I suppose except it didn't do this before I started. That would a big coincedence.

777stickman
10-05-2008, 07:08 PM
Some ?'s

1. From you 2nd post, this all started after the front brake job?

2. Were the new rotors turned and finished prior to installation?

3. Make sure that the rotors and pads are "grease & oil free"! (Sorry, that's not a ?)

4. The rebuilt calipers could be suspect also and it could be either side. (Sorry, that's not a ? either)

CD Smalley
10-05-2008, 07:34 PM
1 - Correct.

2 - They were new out of the box.

3 - They are. I doused them good with brake cleaner once I was done.

4 - Given it pulls to the right. I suspect the left is weak. Or even the new left hose could be weak.

Chevy-SS
10-06-2008, 07:40 AM
Since you have all new components, I might think about looking at another possibility. That is, the crown in the road you are testing on.

As I'm sure you know, all roads have crowns, that is, the center is higher than the edge. This is done so that water will drain off quickly. The crown in the road is why front end alignment settings are often biased to one side, to compensate for the crown.

Anyway, my point is - if you are testing a perfectly good brake system on a crowned road, it will virtually always pull slightly to the right. A much better test would be to go to a parking lot and try braking in a few different directions. If it pulls to the right at all times, in a parking lot, then you know it's either alignment or brake issue.

-

bobss396
10-06-2008, 08:54 AM
I would jack it up and see how easy each side turns. If one is tighter, you probably have a sticky caliper. Which I have seen happen right out of the box. An extremely worn suspension component could do it, but it would be obvious once you shake down the front end.

Bob

CD Smalley
10-06-2008, 09:25 AM
Bob,

So do you think it could be the right side sticking? I would have thought given the pull to the right side, that the left was weak....

Chevy-SS
10-06-2008, 10:17 AM
You won't be able to diagnose strong (or weak) side using hand-rotation of wheels. Both sides will have a little drag. This is perfectly natural for disc brakes. A sticking caliper MIGHT be diagnosed this way, but they usually don't stick all the time.

If you have a sticking caliper, then an easy way to check is to drive truck for a few miles, then bring in - and quickly reach your hand behind each wheel to touch each rotor and see if one is quite a bit hotter than the other. Obviously, the hotter rotor would be the side that is sticking. Of course, be careful as the rotor might be REAL hot. A more accurate method is to measure temp of each rotor using IR (infra-red) temp gauge.

You've installed all new parts and you cleaned the pads and rotors prior to installation. It might be worth spraying everything off one more time with brake cleaner.

I would certainly bleed the brakes again, just to be sure.

Have you tested in flat parking lot?

-

ukrkoz
10-06-2008, 11:58 AM
1. i'd still rotate front end tires just to be sure it's not them. it's like 10 minute job.
2. you never told us where you got your calipers from. many chain stores sell refurbished parts. that it is shiny from the box does not mean anything. i'd call the store and inquire, unless you had them from dealer, then they are new.
3. did you bleed the master? i understand you had 'front hoses" repalced, so i am assuming you did not touch the metal lines, but assumptions are assumptions.
4. harborfreight tools has digital thermometer for very low cost, the laser one. this might be a much better option to check temp out, instead of reaching with your hand.
good luck.

bobss396
10-06-2008, 01:15 PM
I would still jack up the front and see if one takes more effort to turn. One side might get hotter than the other, but you usually get a noticeable burning brake odor with it. But this usually causes a severe pull.

On the side that takes more effort to turn, crack the bleeder and see what happens. You won't be introducing air into the system, so just give it a quick crack and if you get a spurt of fluid, that's the side with the problem. Either the caliper sticks on applying pressure or is not releasing fully.

I've gotten bad calipers before, even have had odd things happening like two different size pistons between the two calipers. Of course the bigger piston will have an increased brake output. But usually you get a sticky caliper that has a cocked piston or scuffed up piston/cylinder wall.

Bob

jdmccright
10-06-2008, 11:27 PM
I'll throw in the chance that one caliper (the left) is not sliding along its slider bolts as well as it should. I will ask this for clarification...when you brake, does the truck initially jerk to the right but then stop straight after you depress the brake further or does it continue to want to veer right? If the first, then I'd suspect the bolts. If the latter, then I'd suspect the caliper itself.

CD Smalley
10-07-2008, 05:51 AM
It's the later. It jerks the wheel to the right and then continues to pull to the right.

I believe there is something wrong on the left side.

bobss396
10-07-2008, 08:26 AM
It could possibly be a caliper hanging up on the bolts. Your calipers should have come with at least the 4 o-rings in the bolt holes. Some I've seen come with the 2 steel bushings.

At any rate, you should make sure that the bolts are not worn and have been cleaned up. A wire brush is good for this. Then look into the calipers to make sure that the o-rings are square in the bores. If you have possibly pinched one, it could stop the caliper from sliding. I used to run a phillips screw driver shaft around the o-ring to make sure it was seated.

Of course you used brake lube on the o-rings and through bolts? This is essential to make sure things keep sliding for the life of the pads. Also apply brake lube to where the caliper contacts the spindle bracket. Wire brush the mating surfaces first.

Use new steel bushings with every brake job, this is cheap insurance and lube them where they go through on the caliper. I've seen the big o-rings pinched as well.

I hope this helps, I'm sure if one of us were there we could nail it down in about a 1/2 hour.

Bob

CD Smalley
10-07-2008, 06:37 PM
New bolts, lube, etc came with the calipers and I used them.

I swapped pads from left to right side as someone mentioned above I think.

That made it better for about 5 stops from 30mph. Then it was right back to pulling to the right.

I went for a drive on a gravel road and did a panic stop from 30mph. It was obvious from the tracks in the gravel the right brake locked up before the left.

I think it must be the left caliper is weak at this point.

Chevy-SS
10-07-2008, 06:44 PM
If you suspect the brake hose, then have someone watch it while you apply the brakes. The hose may be expanding and it could easily be visible.

I would replace caliper and hose on left side................

Curious to see what it ends up being.

-

CD Smalley
10-07-2008, 07:18 PM
I couldn't see it doing so. But I could feel it. Well I could feel the hose get stiff when the pedal was pressed.

But the right side did it too. OK maybe the left felt like it got more stiff or expanded just a touch more.

I'm thinking along the same lines Chevy-SS. I think I will get the new parts tomorrow.

CD Smalley
10-08-2008, 07:37 PM
Latest update.....

Went and talked with the parts guys today. They asked is I would be up for switching rotors from one side to the other before I swapped out the caliper/hose on the left side.

Guess what? After I swapped the rotors, the truck now pulls to the left! So there is something wrong with the one rotor. Some difference in the coating or material on that piece that doesn't allow the pads to grip it as hard or it is wearing off faster.

Wierd huh?

ukrkoz
10-08-2008, 09:05 PM
well, rotors are supposed to be broken in right after installation. properly done, that creates a thin layer of pad material imbeded into the rotor metal. that improves the braking power. i guess, one rotor is softer or something, and got more of that material into itself.
swap it for a different one under warranty. i wouldn't be driving on it.

CD Smalley
10-08-2008, 09:38 PM
I won't be going far that is for sure! 1 mile to work in the morning with a stop at the parts store, 1 mile home tomorrow after work. Fortunately for me, I don't even have to break 40mph.

One more question, have you guys ever heard of truing a new rotor prior to installation?

ukrkoz
10-08-2008, 10:35 PM
never. they come turned outta box. but you must break them in, following break in protocol. will serve you much better.

for the future reference, check on your pads time to time. under condition of caliper freely moving on guides, brake pads wear should be perfectly even on both pads, otherwise you might have hidden problem that caused that rotor to go bad. slight drag in caliper or something.

jdmccright
10-09-2008, 10:05 AM
The driving you do isn't enough to properly break in the new pads. Also, if you reuse the rotors it is recommended that the surface be scuffed for two reasons: 1) to remove any material left by the previous pad, and 2) to remove the shiny, polished surface to help with accepting the new pads. I like to use a 3M scouring wheel used to remove rust attached to a drill. Scour each surface just until they are not shiny anymore, creating a cross-hatch pattern.

Proper break-in involves a series of increasingly firm stops, but NOT panic stops. And no sudden stops for the first few hundred miles if you can help it. This will allow the pads to seat and settle, for them to mate with the rotor surface, and properly heat cycle the rotors (for new ones).

If you buy new rotors, they should already be true and machined with the cross-hatch finish. But proper break-in is critical to avoid future problems such as pulling and rotor warping.

BTW, you should adjust the rear brakes as well to avoid the front ones becoming overtaxed by doing all the braking work, especially during break-in. This is the leading cause of rotor warpage.

CD Smalley
10-09-2008, 12:25 PM
jd - I understand my commute isn't what's needed. But I did a break as described, several increasingly firm stops when I first installed everything. The pulling started immediately and hasn't disappears in about 100 miles of driving since then.

The part store has given me a new rotor to try, which I will tonight.

777stickman
10-09-2008, 05:01 PM
One more question, have you guys ever heard of truing a new rotor prior to installation?

One of the previous responses was "never". I say "always" and I say it from experience. Especially the ones that come from China!!

CD Smalley
10-09-2008, 07:45 PM
777 - you are only the 2nd person I have ever heard that from.

Anyway, got a replacement rotor tonight, put it on, did a few break in stops and guess what.... No more pull to one side or the other....

Go figure. There must be some difference in the steel between the two rotors...

2000CAYukon
10-09-2008, 09:12 PM
One of the previous responses was "never". I say "always" and I say it from experience. Especially the ones that come from China!!

Add me to the list of "always". I once got one that I think someone had dropped but when I worked in a shop (many years ago), we always turned new rotors or drums.

Glad to hear the pull is fixed.

//2000CAYukon

jdmccright
10-10-2008, 09:52 AM
It seems alot of shops will go ahead and turn new rotors simply because it is cheap insurance in preventing a customer from returning to complain about shaking during braking (Shake-N-Brake? :lol: ) ...ok, seriously...

Not to fault them, it could just be who their parts supplier is...the mechs/techs have to deal with whatever brand and type of parts that mgmt buys for them. I know I'd want to check trueness before I installed a new rotor if I worked at a shop...you've got all the tools right there. But being a shadetree mech, I have to choose my parts more carefully and then just take it as it comes.

In any case, glad to hear you found the problem.

CD Smalley
10-10-2008, 12:07 PM
Yup I'm in the same boat jdm. Doing my own work in the driveway...

Thanks to all who replied!

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