pulling to the right

iskyfly · Post by **iskyfly** » Mon Mar 14, 2011 6:13 pm

2005 SXT ATX 85k miles.

I replaced the front rotors and pads (nothing fancy) 4 days ok using the how-to from here. I was pretty surprised about the tight clearances between pads and rotors, maybe something like millimeters, but then again this is my first time doing brakes. There are no squeaks or squeals when braking.

I can't say for sure if this is new or if my head is playing games with me. I've always thought that there was an ever so slight pull to the right. There is a definite pull when I brake (pre and post brake change).

I took out my IR thermometer and checked the temps of the rotors after driving a 15 minute trip. Both were around 110 degrees F.

So my questions are;

-If its the pads that are causing the pull, how to diagnose?

-If the pads are not the cause, how to diagnose?

-What should the clearances be between new rotors and pads?

All four tires are 5 days new. All wheels were aligned. Pressures on the tires checked ok.

Thanks

sidepipe87 · Post by **sidepipe87** » Mon Mar 14, 2011 6:35 pm

It is possible that the caliper is sticking, but I'd think that rotor would be hotter than the other. Other than that, check suspension stuff. Ball joint, lower control arm bushings, tie rod ends, etc. Anything that could be worn and allow movement could cause this.

Post by **occasional demons** » Mon Mar 14, 2011 10:35 pm

If the left caliper is partially seizing, it would cause the right to pull, and not necessarily cause a huge heat difference, as there would be enough time lapsed to even things out.

The left side brake hose could be collapsing internally, restricting pressure/flow to the left caliper. The right caliper would then grab harder pulling you that way. The only way to really know would be to replace the hoses. They should be replaced in pairs to keep things equal.

You could just get the left one, to see if it cures it, but then the right one is older/weaker.

Check the stand off that the pads contact. If there is a big enough dibbit worn into the cast iron, it would cause pad movement problems. But this isn't common with new pads, as they are moved out of the wear area.

iskyfly · Post by **iskyfly** » Tue Mar 15, 2011 11:20 am

(my bold emphasis added)

occasional demons wrote:If the left caliper is partially seizing, it would cause the right to pull,

The right caliper would then grab harder pulling you that way.

thank you OD and sidepipe.

sorry, my simple little mind has become confused.
assuming it is caliper / pad related;

is the pulling to the right caused by the drag / contact of the calipers / pads of the LEFT wheel, or RIGHT wheel?

Danteneon · Post by **Danteneon** » Tue Mar 15, 2011 1:09 pm

The best indicator to a sticking caliper would be the wear of your old pads. Were all 4 pads worn evenly? If not, which pad had more wear (inner or outer, left or right side)?

If the brake caliper is sticking (either the piston or the slides) whatever side is sticking is the direction it will pull.

iskyfly · Post by **iskyfly** » Thu Mar 17, 2011 8:41 pm

I removed the tire, started the engine and put it in neutral. I was able to rotate the rotor by hand. It would stop in less then a rev.

Turned off the engine and removed the caliper. Restarted and put it in neutral. The rotor was spinning freely by the time i got out and checked it.

Is this normal?

Should the rotor spin freely WITH the caliper installed?

Thanks

darthroush · Post by **darthroush** » Thu Mar 17, 2011 9:47 pm

If the rotor doesn't spin with the caliper installed, how is the car going to roll down the road? You apply the brakes and it slows the car by grabbing the rotor.

Post by **racer12306** » Thu Mar 17, 2011 10:06 pm

There should be some resistance when the caliper is installed.

The spinning situation sounds about normal to me.

iskyfly · Post by **iskyfly** » Thu Mar 17, 2011 10:07 pm

darthroush wrote:If the rotor doesn't spin with the caliper installed, how is the car going to roll down the road? You apply the brakes and it slows the car by grabbing the rotor.

let me try again;

should the rotor spin freely with the caliper installed when up on a jack, in neutral and engine running?

hansken_yo · Post by **hansken_yo** » Fri Mar 18, 2011 11:58 am

yes. the rotor should spin fairly freely while the car is in neutral regardless of the engine running or not. the only time it should not spin freely is when the brakes are applied. now mind you that when the car is in gear it should still spin freely, but just in the direction of the gear choice you have selected. the key here is that it should spin freely unless the brakes are applied.

Post by **occasional demons** » Fri Mar 18, 2011 12:34 pm

The o ring on the piston is a square type o ring as in the shape of the rubber cross section, not a square piston/bore. Anyways, the o ring being square, will grip the bore as it is pushed towards the rotor. When pressure is released, the o ring will flex back to it's original shape, pulling the piston back slightly. This keeps the pads from dragging on the rotor. If everything is moving freely, it works well. If not the pads will drag until enough material is worn away.

iskyfly · Post by **iskyfly** » Fri Mar 18, 2011 8:35 pm

hansken_yo wrote: the key here is that it should spin freely unless the brakes are applied.

the more reading that I have done on this the more I wonder if this is true or not.

Some have said that there will always be SOME drag between pads and rotors.

post #4 and 10 here;
http://www.bimmernut.com/forum/5-series ... rotor.html

post #3 and 7 here;
http://www.honda-tech.com/showthread.php?t=147907

As long as you can still spin it with some force, its ok. It shouldnt free-wheel and should be stuck either. That sounds normal.

your pads are always touching the rotors wether you can hear them squealing or not in both the front and back

My own observations;

Rotors spin freely by hand without calipers / pads installed with gear in neutral.

Rotors spin on their own without calipers / pads installed, gear in neutral and engine on.

Rotors will turn only by hand force (and promptly stop when force is removed) with calipers / pads installed, gear in neutral.

I wonder if somebody else could raise one of the front tires, remove tire, gear in neutral and try to spin rotor by hand and see how many revs you get.

Thanks thus far.

Post by **occasional demons** » Fri Mar 18, 2011 10:37 pm

The only way you would get an accurate comparison, would be to remove the driveline parts from the equation. Not a feasible option.

To be more specific on my earlier post, the piston will pull away, but the pads will not. (Well, maybe as long as there is the retaning clip in the piston.) But there should be no pressure holding them against the rotor either, just their own static mass. Vibration alone could move them away from or bounce back and forth a few thousandths of an inch while in motion on the roadway.

So yes, they can and will drag to some degree, but like I stated, if everything is free to move, it is not enough to really have a major impact, or the pads and rotor wouldn't last a thousand miles. I got 120,000 out of my original rotors, about 80,000 out of the pads...

hansken_yo · Post by **hansken_yo** » Sat Mar 19, 2011 4:03 am

occasional demons wrote: So yes, they can and will drag to some degree, but like I stated, if everything is free to move, it is not enough to really have a major impact, or the pads and rotor wouldn't last a thousand miles.

Exactly. I would like to hope that you would know the difference between drag and actual grip. These are subtleties, but really you shouldn't have to struggle to rotate the rotor short of some drag and the actual weight of trying to move the rotor plus the gear box. That would be my definition of freely in regards to the rotor spinning.

iskyfly · Post by **iskyfly** » Sat Mar 19, 2011 12:27 pm

occasional demons wrote:
So yes, they can and will drag to some degree, but like I stated, if everything is free to move, it is not enough to really have a major impact, or the pads and rotor wouldn't last a thousand miles. I got 120,000 out of my original rotors, about 80,000 out of the pads...

thank you very much for bearing with me on this. Learned a lot!

hansken_yo wrote: Exactly. I would like to hope that you would know the difference between drag and actual grip.

I don't think this is knowledge that one is born with. I think if you were to ask most people off the street "should brake pads drag against the rotors when the brake pedal is not pressed?" the majority of the answers would be no. Thats how I would have answered prior to this learning experience.

trying to move the rotor plus the gear box.

Even in neutral?

thanks!

hansken_yo · Post by **hansken_yo** » Sat Mar 19, 2011 2:15 pm

iskyfly wrote:
trying to move the rotor plus the gear box.
Even in neutral?

thanks!

yeah, even in neutral things move in the gear box you just won't have as much resistance than if you were in a gear.