Help - Pulls Ot The Left Under Heavy Braking...

[alfiejts]

My car was in a small bump recently. My son span at low speed, clipped the kerb with the offside front wheel and clobbered the offside rear wing.

Now I have a problem and don't know if it was releted to the accident or a general "wear and tear" issue.

The car drives fine. Up to 85mph no probs - straight & true with no pulling.

Normal braking is fine too. I've even been over snake pass and ezperienced no problems with braking.

BUT - If I brake hard from over 50mph (such as on the motorway), the car veers off to the left - and its quite dangerous.

I've replaced the front pads and discs in case something was spilt on them (such as polish) when the car was being repaired, but it has made no difference.

BUT - I don't really know if it was like this before or if its been caused by the bump.

It could just be some wear in a suspension bush, for example, allowing one part of the suspension to move under heavy braking.

I can't see how it is anything bent from the accident, otherwise it would pull under normal driving.

Has anyone experienced the same sort of issue or are there any common things that wear on the Yaris suspension such as bushes?

(Its a standard 2000 1.0 CDX by the way..... so we're not talking a pocket rocket.... and we've had the car from new, so I know it ws ok at some time in the past...)

I'm just trying to form a view whether its general wear and tear or if its accident related - in which case it can go back there....

[GIDDLEPIN]

It’s worth checking the suspension and tie bar bushes to make sure; it might be worth having the geometry checked as well just to be on the safe side.

Forgive my ignorance but does this model have ABS? If so there could be a sensor fault.

Les

[alfiejts]

Thanks - No ABS on this one, just "ordinary standard brakes".

I've already checked the toe-in alignment front & back and they're all within tolerance.

Anything else is going to need specialist equipment...

[Al J]

So it drives in a straight line with hands off wheel? Careful where you perform this, obviously).

If tracking is ok, then I'm thinking other alignment issues so yes, it needs checking at a garage.

Oh, and what do you mean by "hard" braking over 50mph?

Anyway, irrelevant really, needs checking by the pros.

[alfiejts]

Thanks all - I'll have to get it checked out by the pros.

It drives fine "hands off" al all speeds and under normal braking there is no pull at all.

Its only if you brake hard (to simulate an emergency stop) at over 40 or simulate one of those "oh ****" moments at 70 when the whole motorway comes to a stop and you weren't concentrating and only spotted it late that you get the pull to the left, but its really pronounced then.

At slow speeds, the left front locks up but the right front doesn't....

Its either something really strange with the suspension that only allows some component to "move" when under hard deceleration, or else its a problem with the brake system that's providing more braking power to the left front brake than to the right front brake....

[Red Yaris 54]

At slow speeds, the left front locks up but the right front doesn't....

Its either something really strange with the suspension that only allows some component to "move" when under hard deceleration, or else its a problem with the brake system that's providing more braking power to the left front brake than to the right front brake....

It could well be that your Right front flexible brake hose is weak and inflating (bulging) under hard braking.

This would account for the "normal" braking at low speeds and the "pull" at hard emergency braking.

Hope you get it sorted..............keep us informed

[alfiejts]

Now there's an idea that I could actually relate to....

A bit worrying though, in case they burst!

As I was bleeding the brakes and swapping the brake pads on Saturday, I did think that the rubber hoses were starting to look tired....

Hmmm.

Next thing to try when I'm back from hols is to get it tested on an MOT brake tester to see if the braking is even. If it is, then its off to the garage who repaired the accident damage....

[Ryan1985]

Every RHD cars pulls slightly to the left under heaving braking so you don't end up on the wrong side of the road.

Anyway, you describe it as more serious than a slight pull so I'd get it checked out!

[welshphil]

Every RHD cars pulls slightly to the left under heaving braking so you don't end up on the wrong side of the road.

Anyway, you describe it as more serious than a slight pull so I'd get it checked out!

Any comments,anyone??Interesting concept.

[Woody27]

Every RHD cars pulls slightly to the left under heaving braking so you don't end up on the wrong side of the road.

Anyway, you describe it as more serious than a slight pull so I'd get it checked out!

Any comments,anyone??Interesting concept.

Though this was to do with the camber of the road ie not the car braking hard causing it?

[GIDDLEPIN]

Every RHD cars pulls slightly to the left under heaving braking so you don't end up on the wrong side of the road.

Anyway, you describe it as more serious than a slight pull so I'd get it checked out!

Any comments,anyone??Interesting concept.

Though this was to do with the camber of the road ie not the car braking hard causing it?

Yep Camber it is

Any deliberate intentional bias braking either way would leave the manufacturers wide open to megga claims :shutit:

Les

[welshphil]

Every RHD cars pulls slightly to the left under heaving braking so you don't end up on the wrong side of the road.

Anyway, you describe it as more serious than a slight pull so I'd get it checked out!

Any comments,anyone??Interesting concept.

Though this was to do with the camber of the road ie not the car braking hard causing it?

Yep Camber it is

Any deliberate intentional bias braking either way would leave the manufacturers wide open to megga claims :!Removed!:

Les

Check date of post--a day late for1st April but good try!!!!

[Red Yaris 54]

At slow speeds, the left front locks up but the right front doesn't....

Its either something really strange with the suspension that only allows some component to "move" when under hard deceleration, or else its a problem with the brake system that's providing more braking power to the left front brake than to the right front brake....

It could well be that your Right front flexible brake hose is weak and inflating (bulging) under hard braking.

This would account for the "normal" braking at low speeds and the "pull" at hard emergency braking.

Hope you get it sorted..............keep us informed

So my scientific/ engineering explaination may have helped as this was no April fool :)

[alfiejts]

Turns out to be the rear brakes!

That's why you don't notice it around town and why i tdidn't "tug" at the steering wheel when it veered left, it was the back brakes that were somehow braking in an imbalanced way and causing the car to veer when braking from speed.

Stripped the rear shoes & adjusters down, made sure that the rear slave pistons were free and reassembled everything and all is much improved.

Can't say for sure what the problem was, but rear brakes were definately the cause....

[Woody27]

There is EBD (Electronic Brake Distribution) on the rear wheels if i remember rightly which may have caused this? not sure if it is a Tsport only feature or if on all models etc

[Yaris SR Kid]

Glad you got it sorted!

[LittleM@n]

My car's making the same from speed, it's turning left when braking hard. It turned once at 90degrees just keeping the brake to the metal (it was for test, not real need, but still...).

I've checked also the geometry, wheels, and so on...

So it's the rear brakes that are faulty. What do I have to do? Just take the shoes down like want to change them, and put them careful back on?

Thank you for solving your problem

[alfiejts]

Mine's a non-ABS model, so there's no fancy pumps or EBD electronics that could be causing it.

Just a straightforward old fashioned split-circuit servo assisted brake system.

I took the shoes off, made sure that the automatic adjuster was free and fully wound back in, made sure that the piston was free to move in both directions and reassembled everything.

The one thing to be careful of is that both ends of the adjustment rod have one long leg and one short one.

Its key that the long leg at one end pushes against the auomatic adjustment arm and that at the other, it pushes against the handbrake lever.

I put it all back together (one side at a time) and then made sure I could hear the automatic adjuster clicking as it took up the slack (you have to press on the brake pedal repeatedly until the clicking finally stops, as it winds the auto adjuster out....).

Having done the same on both sides, I then adjusted the handbrake using the nut near the handbrake lever, so that it took the 6-9 clicks specified in the manual.

Once I'd done the above, all was well.

I'd previously changed both front discs, renewed the front pads, stripped down the master cylinder, flushed three litres of brake fluid through the system and replaced a flexible front brake hose with no effect.....

[LittleM@n]

Mine's a non-ABS model, so there's no fancy pumps or EBD electronics that could be causing it.

Just a straightforward old fashioned split-circuit servo assisted brake system.

I took the shoes off, made sure that the automatic adjuster was free and fully wound back in, made sure that the piston was free to move in both directions and reassembled everything.

The one thing to be careful of is that both ends of the adjustment rod have one long leg and one short one.

Its key that the long leg at one end pushes against the auomatic adjustment arm and that at the other, it pushes against the handbrake lever.

I put it all back together (one side at a time) and then made sure I could hear the automatic adjuster clicking as it took up the slack (you have to press on the brake pedal repeatedly until the clicking finally stops, as it winds the auto adjuster out....).

Having done the same on both sides, I then adjusted the handbrake using the nut near the handbrake lever, so that it took the 6-9 clicks specified in the manual.

Once I'd done the above, all was well.

I'd previously changed both front discs, renewed the front pads, stripped down the master cylinder, flushed three litres of brake fluid through the system and replaced a flexible front brake hose with no effect.....

Thanks a lot for the answer.