Car Pulls Right on Braking

[bhuff30]

My 97 GT pulls to the right on braking. It is more noticible with more braking applied. In fact, I can let go of the wheel and watch it turn to the right when I modulate the brakes. From what I've read, I am probably getting more braking on the right side than the left, correct? However, what are the likely causes for this problem on the mustang? As I recall, we have a floating caliper, with no pins for the caliper to bind on. What else would cause it? The system shouldn't have any air. I have never openned it up or run out of brake fluid, in the 100k+ miles I've had the car and this is a new trick.

I recently inspected the brake pads. They still have plenty of life. It seemed like there might be a little bit of looseness in the left front wheel hub, but this shouldn't have any effect when braking, correct?

 

[N8Dogg98]

No clue man... I have the same problem with my '98 and I've upgraded to the Mach 1/Bullitt brake kit and the issue is still present at times. The weird thing is it's completely intermittent. Sometimes it does it.. sometimes it doesn't...

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[Superhereaux]

100k and you've never changed the brake fluid? Not saying its the cause but after a few years, brake fluid absorbs a certain amount of moisture from the air. Corrosion from that could cause blockage of some sort or create air pockets from steam heating up and expanding a bit more on one side or the other (intermittent). It's a long shot and probably not the cause but that fluid needs to be changed either way.

Also, have you or anyone installed brake pads lately? I've seen people crack the bleeder screw to pry back the brake piston. Easy way to get air into the system.

The wheel bearing, hmm, I'd have to think about that one...

 

[blkstanger]

After 100k with no real maintenance on the brake system you will probably need a new pair of front calipers. Or at the very least a good cleaning up. That along with a brake fluid flush should get you back to where your brake system should be. And when you are done with the front you had better pay some attention to the rears. Some things don't last forever without a little love. Oh and check your front bearings while you are there.

 

[flstang65]

Sounds like you have a sticking caliper or a bad brake hose. I would do a brake flush too.

 

[bhuff30]

I can bleed the brakes, but I don't think that's an issue at all. The pedal feels firm and has plenty of stopping power when needed.

I installed rear pads a while back, but I used the correct tool to screw the piston back to the initial position. I didn't crack the lines open or anything like that.

I guess the next step, I will inspect the calipers and pads again, but when I changed the rear pads, all of the front pads seemed to have plenty of life and were worn normally. I can also change the fluid for fun. I can understand changing the fluid on a track car yearly (or even every race), but on a street car, it doesn't seem very necessary since the speeds are low and the brakes never get that hot.

 

[SteedaGT9150]

Sounds like you have a sticking caliper or a bad brake hose. I would do a brake flush too.

My dad's rubicon did this and it ended up being a sticking caliper on the front passenger side.

 

[bhuff30]

Everyone is saying a sticking caliper, but what is sticking? Do you mean the piston is sticking in the bore or the caliper isn't sliding smoothly on it's mounts?

 

[N8Dogg98]

Everyone is saying a sticking caliper, but what is sticking? Do you mean the piston is sticking in the bore or the caliper isn't sliding smoothly on it's mounts?

I'm curious as well. Like said above, my car has done the same thing on occasion, but not always. It did it when I had the stock calipers, hawk HPS pads, and powerslot rotors, and it still does it now with the 13" Cobra/Mach 1 brake kit (13" brembo rotors, stock Motorcraft pads, and 2 piston PBR Cobra/Mach 1 caliper). I bled the brakes when I did the 13" upgrade and installed braided lines.

I guess it doesn't really bother me much as it only does it maybe 1 out of 20 times when I depress the brakes, but it is weird. BHuff is right too, it really pulls to one side aggressively. If you let go of the steering wheel the steering wheel will literally turn at least 25*!

The fact that it has happened in my car before AND after a complete brake upgrade leads me to believe it has nothing to do with the calipers, pads or rotors.

 

[Maxium]

Mine does this sometimes as well. I have the Mach 1/Cobra brakes. Brakes are firm, fluid is pretty new. Pads/rotors are new. I also get more brake dust on my passenger front rim. Would be interested to see if we could figure this out.

 

[HorsePower03]

Everyone is saying a sticking caliper, but what is sticking? Do you mean the piston is sticking in the bore or the caliper isn't sliding smoothly on it's mounts?

Calipers eventually go bad and can freeze up on you. If you do a brake job and try to compress your caliper piston, I'm betting one of them won't compress or will be way more difficult than it should be. Also, like everyone said, you need a brake flush if you haven't done it in over 100k miles. Not because it's a race car and it's getting hot, but for the reasons Superhereaux said. I bet your brake fluid is a nice ugly green by now.

 

[hotcobra03]

a sticky caliper can also be seen with jacking wheel off ground and spinning it,,,wheel should spin freely,,,a sticky caliper would make wheel hang up ...

dont rule out the rear brakes..they too can make car drift...

are you using a wider rim that stock?

 

[HorsePower03]

Also, when you inspected your brake pads, did you look through the wheel at the pads on the outside, or did you remove the wheel and look at both pads on each side? Sometimes a caliper sticking will wear the hell out of the inside pad without really wearing the outside pad.

 

[bhuff30]

I am posting an update to this thread so that those with similar problems can find the information in a search.

In my case, the problem was a bad ball joint on the right side. During inspection and wheel wiggling, I never could wiggle the wheel hard enough to show the ball joint was getting loose. It simply started making a groaning/creeking noise. The boot was broken, so I greased up the joint and ordered parts. I finally got around to installing the ball joints and the pulling problem seems to be fixed.

 

[03_TrueBlue_GT]

Thats good to hear! Mine pulls to the right when I brake hard as well, I know its my alignment though because it pulls to the right slightly every time I am just driving.

 

[Alin]

A loose ball joint will change the alignment angle and will cause a pull while driving , and a stronger pull while braking . The first suspect of course would be the caliper or a collapsed brake hose but in some cases replacing those didn't fix the problem so suspension (ball joint) seems to be the culprit