Thread: Def swerves on left braking - HELP ME PLEASE

My first thought was front radius arm bushes, as I've had the same problem in the past. If they have already been replaced it rules them out.

Do you have anywhere that you can do a simple test to check if one of the front brakes is more effective than the other? I'm thinking somewhere that isn't high traction - like a gravel road - that you can disable ABS and see if one wheel (likely the left front) tends to lock up first.

In your list of things replaced I don't see front brake pads. Did you replace those when the discs were replaced? Any chance you've got a mis-matched set of pads in the front?

Steve

Originally Posted by steveG

My first thought was front radius arm bushes, as I've had the same problem in the past. If they have already been replaced it rules them out.

I've put down the two radius arm to see the bushes but they were in good condition so I didn't changed them and tight well the nuts..

Originally Posted by steveG

In your list of things replaced I don't see front brake pads. Did you replace those when the discs were replaced? Any chance you've got a mis-matched set of pads in the front?

Tnx Steve! Sure, brand new

If its pulling hard to the left, it may be as simple as the right hand front calliper sticking, it may be still working but if one or more of the dust seals have failed and dirt or dust has entered the calliper pot it may be fouling or sticking on the calliper bore causing drag. If you jack the vehicle up so both front wheels are in the air and have someone apply the brake pedal lightly and see if you can feel a difference in the force needed to rotate each tyre. There are machines around at various mechanics who can measure the braking efficiency as a percentage from one corner of your car to another.
If you find that calliper is sticking, simply pull the calliper pistons out and give them a quick scotch bright, preferably in a lathe if you have access to one, make sure the calliper bore is free of any rubbish and smooth, then replace the cylinders with a new seal kit installed and a little bit of lube.
If you rebuild the sticking calliper i would recommend you also do the one on the other side so you know they are both working at 100% and the vehicle doesn't start pulling the other way because you have done such a good job on that calliper that it is now more efficient than the one on the left

Originally Posted by MickMc

If its pulling hard to the left, it may be as simple as the right hand front calliper sticking, it may be still working but if one or more of the dust seals have failed and dirt or dust has entered the calliper pot it may be fouling or sticking on the calliper bore causing drag. If you jack the vehicle up so both front wheels are in the air and have someone apply the brake pedal lightly and see if you can feel a difference in the force needed to rotate each tyre. There are machines around at various mechanics who can measure the braking efficiency as a percentage from one corner of your car to another.
If you find that calliper is sticking, simply pull the calliper pistons out and give them a quick scotch bright, preferably in a lathe if you have access to one, make sure the calliper bore is free of any rubbish and smooth, then replace the cylinders with a new seal kit installed and a little bit of lube.
If you rebuild the sticking calliper i would recommend you also do the one on the other side so you know they are both working at 100% and the vehicle doesn't start pulling the other way because you have done such a good job on that calliper that it is now more efficient than the one on the left

As I said in the first post, doing your reasoning at the time I've changed all 4 brake calipers with 4 new and the problem is the same. Identical! Obviusly always the sistem as been well purged. The problem can't be the callipers

when it pulls to the left - what happens? Is the steering wheel pullign out of your hand - ie if you let go of the wheel does it start turning on it's own?

If you hold the wheel straight - is it still pulling?

If you brake to the point of wheel lock up on a gravel surface - does one wheel always lock up in preference to the others - does the ABS kick in?

You don't mention brake pads - I assume these were changed?

Hi

I have the exact same problem.

I only got it after changing all brakes, rebuilding swivels (preload good) full polybush and new sumo bars with new ends. New BFG 255/85/16 mt. Wheel alignment set to zero. All parts oem or better.

Standard height springs and std shocks, condition unknown.

Normal braking no problem but when you brake harder it pulls to the right though, my Defender is LHD though? Braking really hard is sufficient to feel like rear steering and the front gets unsettled and locks the front right, maybe the centre bush on the rear axle?

My plan now is to lock the steering box straight ahead, I have been told there is a screw to do this and check the steering is all adjusted correctly.

Then renew the springs/shocks.

Subscribed.

Steve

Have you checked the wheel bearings. You may have knock off. Even though you have done the disc's it may be a bit loose.
Matt.

Just a guess as you've already tried so much, but could it be something to do with your tyres - maybe uneven wear, or differing weights or pressures?