Thread: Def swerves on left braking - HELP ME PLEASE

Originally Posted by DiscoMick

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?

The problem is not in the tyres as my tyres are new and I have also an other 4 wheel and the problem is always present.

Tail wagging the dog? Checked your trailing arm bushes? Can you also induce 'power steering' under full power in first or second gear?

Originally Posted by n plus one

Tail wagging the dog? Checked your trailing arm bushes? Can you also induce 'power steering' under full power in first or second gear?

Yes, braking I have the impression that the back goes away and after (a lot of time) che ABS try to correct. The sensation is like turning the steering wheel when you brake even thought the steering wheel stay straight

The problem appears only braking. accelerating also with full power in any gear don't have any strange effect

When you changed your calipers and discs did you check your brake lines also?

I don't know whether a bulging brake line on one side could cause something this dramatic but its worth a check if you haven't.

Originally Posted by bismillah

It's a very good question... I would say NO. Holding the steering wheel and braking you feel that you are going to the left with the front of the car and indeed you find looking in this direction even if you are always holding the steering well straight. If you don't hold the wheel it tend to rotate a minumum to the left but is a minumum seen the entity of the swerve

It sounds like the rear axle is moving away from its mountings on one side under braking. This would cause the car to 'slew' sideways like you describe.

Agree with it8x7. If it were uneven brakes the wheel would pull violently, and you would definitely notice one wheel locking up on dirt. You might be able to simulate the axle movement by putting the hand brake on and getting someone to push it backward and forward, you may see some interesting axle movement.

The most common cause of this effect is free play on one of the lower links locating the rear axle, most commonly the bush where it attaches to the axle.

John

Originally Posted by JDNSW

The most common cause of this effect is free play on one of the lower links locating the rear axle, most commonly the bush where it attaches to the axle.

John

Thanks John!

Last mechanic who deal with my car said he checked all the bushing and he didn't found any plays. Do I have to believe him? How can I check more?

My point of view is that the the problem is something that seems to be ok but on the other hand is not...
We are talking about a car that has 150k km and is kept perfectly with passionate attention