I've test driven 3 EXCs that have a very noticeable pull to the left when braking. The harder I brake, the harder it pulls. In some cases the tires lock-up. What are possible causes? Brakes? Alignment? Any way to tell for sure?

If the wheels are locking, does that suggest ABS is not working? or not working properly? I'd assume ABS should never allow the wheels to lock-up?

 

Excursions aren't usually known for brake pull problems so this is a pretty difficult question to answer. Since you have driven 3 of them with the exact same issue, the first thought that comes to mind is road related. Did you drive all 3 over the same route?

If the vehicles had not been driven for a while, the right front caliper might have siezed which would cause it to pull to the left. If it is a rear brake that's locking up, then possibly a frozen e-brake cable.

Beyond that, it could be a worn part in the front suspension or steering. It's also possible that it may be tire pressure or alignment related but those issues would ordinarily cause it to pull all the time, not just under braking.

Of course, there is always the possibility of accident damage that remains unrepaired but that doesn't seem likely in all 3 vehicles.

ABS would not cause the brakes to lock up, however, it should respond to a lock up within a half second or so. It should release and re-apply pressure to the offending wheel making the pedal pulsate. I do not recall if the Ex is 3 channel or 4 channel ABS. If 3 channel, one rear wheel locked up might not be enough to pulse the brake pressure immediately. I also do not know if there is a difference in the ABS between 2 and 4 wheel drive, diesel or gas. Were all 3 vehicles the same drivetrain configuration?

Sorry to be so broad but that's about all I can think of with the information you've supplied. If we were talking about a specific problem on one specifice car we could ask for a lot more details and possibly get to the bottom of this. Hope this helps.

Lou

 

All were 4wd (disengaged). Each were on different roads. I perceived - but could be wrong - that the front-left wheel was locking -- thus the pull to the left. I could lock the breaks so-as to leave a few feet skid mark at 20-25mph.

 

In the one I drove today, I informed the owner. Frankly, it seems dangerous to me. In a sudden stop.. the vehicle is going to pull hard into oncoming traffic. If I was not holding the wheel, it moved over a lane width in about a second.

 

Did any of these vehicles have brake pulsation? A badly warped rotor might also cause that and is a common problem. Otherwise, I would have to suspect a worn front end part allowing the wheel to shift when brakes applied. There is not too much to go wrong on the front end of a solid axle 4 wheel drive. Wheel bearings and ball joints seem popular. I can't relate any personal experience as my Ex is 2WD.

Lou

 

I have an 04 X that I've owned since new. It's my impression that the stock brake material is ineffective until it's hot. I don't use my brakes much. I drive long distances and I tend to slow down in advance of stops I can predict. It's not uncommon that my brakes would be "cold" ... as in not used in the last 30 minutes. My brake controller (for instance) powersaves after 30 minutes --- and I often notice that it's display is off.

Anyways... I noticed two things recently...

1. It seems that the brakes are quite a lot more effective when hot. I had a panic stop recently where someone ahead of me came to a sudden unexplained stop. I slammed my foot on the pedal about as hard as I ever have. The truck initially started to stop far too slowly --- it scared me --- then after half a second it hauled itself to a stop appropriately. My only way of explaining this is that half second was about the brake parts warming up.

2. I've also recently had pulling. Comically, it seems to pull to the left, then pull to the right, then stop straight. It also seems to happen when the brakes are cold and I'm stopping relatively hard. Now this could be a steering system thing too --- about how the front wheels are under different pressures when used for braking --- I dunno. The effect is small... easily handled with the wheel... but I'd like to solve it before winter.

It's also my impression that these brakes won't lock up the wheels on dry pavement. I've been thinking of replacing them with an upgrade. For now I just leave extra space.

 

ABS should not lock if working correctly.. "antilock brake system"

 

I'm betting on a frozen caliper. Just replaced mine 2 months ago under my 90 day used car warranty. Disc brakes pulling left or right = Frozen Caliper 9 out of 10 times. Ernie.

 

for a frozen caliper.. is there a way to unfreeze.. and re-use.. or must it be replaced?

 

I have recenty bought a 02 4wd X, and it seem that you are experiencing the same hard poll to the left as I had . I had the Ball joints replaced and now the truck stops fine, that my be the problem.

 

You guys don't weigh like 900#'s or anything and that could possibly be the source of the pull to the left now could it?

Sorry...couldn't resist...

joe.

 

If the piston is not stuck you can remove and clean/replace the slide pins. This way the caliper will float and not brake uneven. However is a piston is not moving in the bore you will have to rebuild/replace the caliper.

I put my $$ on pads that need replacing. I had the same problem and went to Ceramic pads and new pins and now stops straight ahead. 7.3 2000 Ex

 

PRETTY CLOSE! Just ask the wife.

 

On the one EX that I drove, the owner made the point of having the brakes done this spring. I told her to take it back to them.