Pulling to the left when brakes are applied

[Falcon_LS]

This morning I noticed my Grand Marquis pulls to the left when braking. How severely it pulls depends on how hard you apply the brakes.

I know the suspension and front end is good, so I'm looking at the front brakes. The first thing I'm going to try is to swap the rotors around, then regrease the caliper pins and pad mounts on the caliper with dialectic grease.

I have noticed something when I was rotating my tires the other day though. The left tire in particular requires a good bit of effort to spin around, and will not spin freely when the front end is jacked up. The right is the same, but not as hard to rotate. I'm not making any conclusions yet, but is it safe to assume I have a stuck caliper on the left? Thanks!

 

[Thax]

Most likely a stuck caliper.

 

[eagle23]

+1 on the stuck caliper on the left.

I'm not sure swapping rotors will get you anywhere.

Greasing the slide pins may do the trick. Otherwise, replacing or rebuilding the caliper seems in order.

 

[Astro14]

I wouldn't bother with swapping rotors - the pads have bedded in to those rotors, so depending on pad/rotor contact, swapping may or may not change the pull...but swapping will reduce your braking effectiveness because the pad/rotor contact will be reduced until they bed in to their new position.

Not sure you can tell which caliper is defective from the description or the pull (e.g. if the right one has failed, and the piston is sticking, braking effectiveness on teh right is reduced and the car pulls left...) - have someone operate the brakes while the car is up and wheels are off - look for normal sliding/movement...

You might consider replacing hoses - a failing hose can act like a one way valve and apply residual pressure to an otherwise good caliper...

 

[demarpaint]

Originally Posted By: eagle23
+1 on the stuck caliper on the left.

I'm not sure swapping rotors will get you anywhere.

Greasing the slide pins may do the trick. Otherwise, replacing or rebuilding the caliper seems in order.


+1. The calipers are easy enough to take off and lube the slide pins. You can also attempt pulling the caliper off the rotor, compressing it, putting it back on, step on the brake petal, then bleed the offending caliper. There could be a small bit of junk in it [perhaps from the inside of a brake line. It happens] causing it to hang up a bit. Worse case is you have to rebuild or replace the caliper, and inspect and/or replace a brake line if needed. If it were mine and lubing the slide pins didn't work that's what I'd do. JMO

 

[Falcon_LS]

Thanks very much for all the input!

I haven't had the time to do anything yet, but I just came back from a drive. After some hard braking, the car stopped pulling to the left. But I can hear a clicking sound coming from the left caliper when the brake pedal is released. It's not loud, but you can hear it when the vehicle is stationary and you operate the brakes. Any ideas as to what could be causing it?

Having said that, I replace my brake fluid whenever I do a brake job or every 25,000 miles or 12 months. It was last done 3 months back, but it might be worthwhile to bleed the brakes and put some fresh DOT 4 in there again.

 

[demarpaint]

It could be hanging up. I'd do what I mentioned above first if you'd rather not replace a caliper/line. I've done it over the years with success.

 

[Falcon_LS]

Thanks very much, demarpaint! I will try that this afternoon.

 

[demarpaint]

Originally Posted By: Falcon_LS
Thanks very much, demarpaint! I will try that this afternoon.

Sounds good, please report back! Good luck.

 

[oppirs]

Couldn't hurt as to DOT fluid. With your update, greasing slide pins may stop clicking. If you bleed them, your gonna get up close to those calipers. Good time to yank, pull, push on those baby's.

 

[Falcon_LS]

Thanks a lot for all the info!

I followed demarpaint's advice last night, pulling the front calipers off, cleaning, compressing and bleeding the system. I also lubed the pins with dialectic grease. There was quite a bit of junk in there, probably because the previous owner never replaced the brake fluid.

The brakes are much better now, especially after some fresh DOT 4 in there. But after seeing the stuff that came out, I'm thinking about replacing my brake lines and hoses, for peace of mind more than anything. My front rotors will also require replacement in the not too distant future.

 

[artificialist]

Originally Posted By: Falcon_LS
Thanks a lot for all the info!

I followed demarpaint's advice last night, pulling the front calipers off, cleaning, compressing and bleeding the system. I also lubed the pins with dialectic grease. There was quite a bit of junk in there, probably because the previous owner never replaced the brake fluid.

The brakes are much better now, especially after some fresh DOT 4 in there. But after seeing the stuff that came out, I'm thinking about replacing my brake lines and hoses, for peace of mind more than anything. My front rotors will also require replacement in the not too distant future.

It is good to replace hoses in this situation.

In many cases I have seen, when a caliper drags, it often generates enough heat to permanently weaken the brake fluid hose.

 

[garlicbreadman]

make sure the brake hoses are not clogged, this would give the same result as a stuck caliper