Thread: Def swerves on left braking - HELP ME PLEASE

You have checked many things and replaced many things - but no fix.

You have identified two issues - sensors and steering box alignment.

On 30th July you say you did roller test with 2 to 3 percent difference. Was the test done with the ABS fuse in or out?

Have you had steering alignment checked professionally since finding steering box not aligned properly? On 16th August you say there was steering bump at 100k/h and mechanic changed steering rod joints. Was vehicle pulling left before mechanic changed steering rod joints?

Regarding 'rear steer'. You say rear rubber bushes are good. You say when braking gently from high speed you still get left pull. Is the pull still very strong or does the strength of the pull match the gentleness of the braking. Those of you who have experienced rear steer, is it only evident with strong braking, or always evident regardless of whether soft or hard braking?

Otherwise, I think you are going to have to patiently re-check everything from front to rear again.

Have you experienced any improvement at all since making all those changes?

My guess now is the brakes are working fine on the side that the Land Rover is pulling to. It could be that there is something wrong on the other side that is reducing the braking effect on that side ( maybe a mechanic with oily fingers contaminated the pads when they were fitted ) .

Change all the pads for new ( again ) and look carefully at the calipers in case they are sticking.

Watch out for any oil leaks that may be coming out of the hub seal.

The ABS modulator operation is the the next thing on the list if the above doesn't work.
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Wrinklearthur, I was pondering your quote. If we had the right people in place we would not have military hardware!? Other than to play with of course

As always a big thanks for all the answers dear friends

Originally Posted by workingonit

You have checked many things and replaced many things - but no fix.

I think you're right

You have identified two issues - sensors and steering box alignment.

Originally Posted by workingonit

On 30th July you say you did roller test with 2 to 3 percent difference. Was the test done with the ABS fuse in or out?

The test was done initially without the fuse because the TC/ABS started as the the test run (the test wasn't able to test 4x4 veicle) and we find this irrilevant difference. I also drove the car without the fuse and the problem was identical, identical, identical. Some days after I repeated the test with the fuse in elsewhere and was the same.

The strange speed in the rear left wheel is a bug of my nanocom as with my friend's newer instrument al the speeds are ok.

Originally Posted by workingonit

Have you had steering alignment checked professionally since finding steering box not aligned properly?

No, I did myself.

Originally Posted by workingonit

On 16th August you say there was steering bump at 100k/h and mechanic changed steering rod joints. Was vehicle pulling left before mechanic changed steering rod joints?

I remember the car braking straight since new, after I had this problem of steering bump that was fixed by a mechanic changing front bushings and three rod joints. After some month I realize this braking problem ... I also told to all mechanics that I realize the problem some month after this fix (as in this time I didn't brake from 100km/h so much) but all the mechanics said it is all ok... but if I foud the steering box not centred they have not looked good..

Originally Posted by workingonit

Regarding 'rear steer'. You say rear rubber bushes are good. You say when braking gently from high speed you still get left pull. Is the pull still very strong or does the strength of the pull match the gentleness of the braking. Those of you who have experienced rear steer, is it only evident with strong braking, or always evident regardless of whether soft or hard braking?

Imagine you driving straight at 100km/h. One hand on the steering wheel, the car go straight and it doesn't need any correction. You press the brake as you what to slow down and, always with the steering wheel in the same position you feel the car going left. The feeling is like if you from the center point turn the steering wheel to the left. Therefore, when I slow down normally I have always to compensate a little bit with the steering wheel to the right but I have to turn. Obviously if at that speed I brake strong wow the car turns left.

The problem is evident al relatively hi speed.. If you brake from 50-60km/h seems there is no problem

Originally Posted by wrinklearthur

Have you experienced any improvement at all since making all those changes?

No, dam

Originally Posted by wrinklearthur

My guess now is the brakes are working fine on the side that the Land Rover is pulling to. It could be that there is something wrong on the other side that is reducing the braking effect on that side ( maybe a mechanic with oily fingers contaminated the pads when they were fitted ) .

Change all the pads for new ( again ) and look carefully at the calipers in case they are sticking.

Watch out for any oil leaks that may be coming out of the hub seal.

I personally changed all the disks, calliper and whell brearing thinking to solve the problem but no modification. I already changed three set of braking pads. Now I have all original LR.

Originally Posted by wrinklearthur

The ABS modulator operation is the the next thing on the list if the above doesn't work.
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I said I tryed to mount ad Abs modulator lend from a friend. The same..

Did your mechanic do any other 'repairs' apart from replace the ball joints? Wheel bearings? Swivel pin? Have you done any repair?

Pity the steering wheel was removed to get rid of 45 degrees. I would have tried adjusting the drag link length to get rid of the 45 degrees provided the drag link/track rod were not bent. With difficulty I just measured my 82 Range and 94 Disco - 1230mm centre to centre for track rod and 925mm for drag link - Haynes manual says 1230 and 924. Don't know if your vehicle requires these settings. If yes, but you find your measurements are different you may have some cause for concern regarding alignment. Toe out (not in) between 0mm and 2mm. It is the only obvious problem you have found and I think the alignment is still not correct - that is my bet.

The manuals say pulling to one side can be brake pad material (rule that out), seized caliper (rule that out), lose caliper bolts (?), suspension rubber wear (?), wheel bearing wear (?), swivel pin pre-load (? and add to that bearing race for swivel pin not seated properly). I would be checking all the (?) again after checking steering alignment.

Steering box. I would expect normal wear to be even side to side and you would pull left or right just as often. Is power steering hydraulic pressure still uneven after getting rid of 45 degrees? I doubt that it is the steering box.

If your mechanic did nothing else other than the ball joints then all the mechanic seemed to have done was not adjust the distances properly on track and/or drag links ie you get 45 degrees. Is it possible worn ball joints compensated for wear elsewhere. Once the ball joints were new and tight then compensation was no longer available to the other worn item that we may be seeking?

Unlikely an issue, is your rear axle controlled by an A frame? Check chassis mount brackets have not been crushed or misaligned (by landing on a rock).

Getting to the point that I can't think of anything else. Maybe you should trade it for a nice Italian sports car...or a G-Wagon if you want to continue 4x4ing

I wonder if one of the flexible brake line on the front has delaminated inside itself, or there is some rubbish in one of the brake lines?

Fluid may be starting to go to the caliper on the faulty corner than get shut off.
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The way to check for uneven braking is to try hard braking at various speed on a dirt track. If you have uneven braking you will find that one wheel will lock up in preference to the others. Better to try this without the ABS fuse - alternatively you can disable abs by pressing the brake pedal 10 times in the space of 1 minute before you start the engine. (Your ABS light will flash, at least that's how I remember it). Hard braking will lock up all four wheels in theory if your ABS is off. What you want to do is practice getting to the point of lock up and then a little bit more. You can see which side is locking up by looking at the skid marks. ( I've tried this on my lawn, but my wife was a little upset...)

Seems all four wheels were tested and only a few percent difference if I read correctly.

I wonder if you could see some unusual component movement by putting the vehicle up on stands. Get all four wheels spinning. While someone is braking someone else can watch the under carriage for movements or listen for unexpected noises?