Steering veers under braking

[GrahamS]

Recently been having a rather annoying problem.

When I brake my steering wheel goes right a bit and the car feels unstable. When I take my foot off the brake the steering wheel goes back left again to where it was before.

Track rods and all suspension is all new. Haven't hit any curbs
Problem is worse at high speed and when braking harder .

Cheers chaps

 

[Advikaz]

Could be a sticky/binding caliper.

Tracking ok?

 

[loggyboy]

Despite anything previously done, I would get tracking checked.

 

[GrahamS]

Forgot to mention, tracking was done when suspension all replaced. Would I be looking at a right caliper sticking of left?

 

[imprezaworks]

At a guees the left caliper is sticking if its going right when braking. Worth getting it somewhere to get the brakes checked

 

[GrahamS]

Yeah I thought right may be working okay and left is busted. I only refurbed the calipers earlier in the year so something must have got crappy.

Will get it on the brake bias machine at the garage and see what's happening. Not sure if they check the front bias at the mot. It only passed in September but has got a lot worse since

 

[loggyboy]

Best way to test if its brake related, is to see if there are similar but possibly less pronounced issues when simply backing off and accelerating.

 

[CamMoreRon]

I would get the tracking checked just in case, but it sounds like a seized front left caliper.

 

[GrahamS]

Update

Thanks for all the replies. I've concluded its 100% brake related.
During the week I quickly too the front calipers off. Sliders are totally free. Exercised the piston in and out a few times and didn't have any difficulty doing that. This however has made no difference to the problem.

Does any know know the torque settings for the sliders bolts?

This is what the brake machine is showing after the clean up and this ties up with the problem. Rears are absolutely fine, showing around 100 both sides if I remember correctly.

 

[cranked]

I have a similar problem with car feeling abit unstable under heavy braking although I think I have an issue with the left rear as there seems to be an area at the edge of my disc that stays rusted colour. Discs and pads are all new so can only think its piston related.

 

[GrahamS]

Okay so I've done a few more things but this problem still exists.

Bled the brakes, no difference.
Swapped the caliper piston over with a spare I had, no difference.

Could this be master cylinder/ABS pump related? I have no idea so am after help on that.

 

[loggyboy]

Is the imbalance on the brake rollers still there?

 

[GrahamS]

Is the imbalance on the brake rollers still there?

I haven't checked but the symptoms are exactly the same. Steering wheel moves of it's own accords and if I hold it in place and brake the car flies to the left.

 

[GrahamS]

Noone? Checked all bolts on the side with the problem but they're all tight.

 

[Edges]

Did you check the pads aren't seized in the caliper? Brake flexi pipe could be collapsed too.

 

[GrahamS]

Did you check the pads aren't seized in the caliper? Brake flexi pipe could be collapsed too.

Yeah, it was all brand spanking new in April and refurbed.

I read around on the net and thought it may be a collapsed hose so have got one in the post!! If it is that rejoice. If it's not that it's the solid pipe from the abs pump or the pump it's self

 

[STEVE.M]

Update

Thanks for all the replies. I've concluded its 100% brake related.
During the week I quickly too the front calipers off. Sliders are totally free. Exercised the piston in and out a few times and didn't have any difficulty doing that. This however has made no difference to the problem.

Does any know know the torque settings for the sliders bolts?

This is what the brake machine is showing after the clean up and this ties up with the problem. Rears are absolutely fine, showing around 100 both sides if I remember correctly.

Hi Graham,correct me if I`m wrong,but isn`t the right hand guage for the right hand wheel.If so the less efficient right hand brake will make the car pull to the left,and you are moving the steering wheel to the right to keep it in a straight line?
AS there may be multiple issues here,did you change the bottom wishbones as part of your suspension refurb,and I believe you said you changed the brake pads?Please confirm this.
I am making the assumption that the discs are in good condition on both inner and outer faces and of the same thickness.

 

[GrahamS]

Hi Graham,correct me if I`m wrong,but isn`t the right hand guage for the right hand wheel.If so the less efficient right hand brake will make the car pull to the left,and you are moving the steering wheel to the right to keep it in a straight line?
AS there may be multiple issues here,did you change the bottom wishbones as part of your suspension refurb,and I believe you said you changed the brake pads?Please confirm this.
I am making the assumption that the discs are in good condition on both inner and outer faces and of the same thickness.

Yeah sorry Steve, let me explain a little better. The car pulls to the left if you forceably keep the steering wheel in the same place. If you lightly hold it the pull is severe and causes the wheel to turn clockwise which keeps the car in roughly a straight line, when I let off the brakes it immediately goes back to where it was before and the car then lurches right while the steering wheel corrects back. Besides that this is what I replaced when doing the front of the car.

I checked the pads and they have worn evenly, the disc is still in almost brand new condition as the majority of my driving is on the motorway.

Brand new
Shocks, inner and outer track rods, lower ball joints, brembo discs and pads.
Refurbished calipers using bigredd seal kit.
Front end has inner and outer arb powerflex bushes along with powerflex wishbone bushes
Rear lines are braided but the front lines are the original rubber hoses.

All bolts are still how they should be and there is no sign of parts moving which shouldn't.

At the time

 

[car.crash]

My car did this and I couldn't find the issue.
When we stripped the front tyres off for replacement one of them had lots of loose rubber balls inside and the tyre was trashed but looked fine on outside.

It had been run flat for a short period and ruined the wall and made it soft according to tyre man.

New tyres were fitted and the problem went away.


I would also be looking at your wishbones despite being polybushed.

 

[GrahamS]

My car did this and I couldn't find the issue.
When we stripped the front tyres off for replacement one of them had lots of loose rubber balls inside and the tyre was trashed but looked fine on outside.

It had been run flat for a short period and ruined the wall and made it soft according to tyre man.

New tyres were fitted and the problem went away.


I would also be looking at your wishbones despite being polybushed.

Ahh adding to the above the tyres were brand new rainsport 2s and have only done 2k! It would be easier to list the parts which haven't been replace Will give my 172 wheels a go though definitely.

What would you be looking for on the wishbone? The ball joint is in good condition and doesn't have any play I know that for sure. When I did the 3 and 9 o'clock shake of the wheel there was no movement, the same for the 12 and 6 shake.

 

[car.crash]

I would take a look at the condition of the bush and the bolt.
Get a pry bar on them and see what moves.

 

[Edges]

I know you've said you had the tracking done but I'd be checking it again.. Maybe the suspension has settled since and requires a re adjust. Or something really isn't bolted up in the correct place!

 

[STEVE.M]

Yeah sorry Steve, let me explain a little better. The car pulls to the left if you forceably keep the steering wheel in the same place. If you lightly hold it the pull is severe and causes the wheel to turn clockwise which keeps the car in roughly a straight line, when I let off the brakes it immediately goes back to where it was before and the car then lurches right while the steering wheel corrects back. Besides that this is what I replaced when doing the front of the car.

I checked the pads and they have worn evenly, the disc is still in almost brand new condition as the majority of my driving is on the motorway.

Brand new
Shocks, inner and outer track rods, lower ball joints, brembo discs and pads.
Refurbished calipers using bigredd seal kit.
Front end has inner and outer arb powerflex bushes along with powerflex wishbone bushes
Rear lines are braided but the front lines are the original rubber hoses.

All bolts are still how they should be and there is no sign of parts moving which shouldn't.

At the time

Hi Graham,that`s a pretty comprehensive list.The only ommission is the springs,which look pretty good in the pic.A weak right will give a bit of neg camber under braking,increasing the toe in slightly,and add to the LH pull slightly,but your problem is way above this.
I did think about tyres,but the rainsports which I`m sure you run at the correct pressures rule that out.
I rubbed off most of the info on the sidewall of my LHF PS3 at Llandow,but don`t any braking problems.
The tracking seems good,as it is appearing to attempt to keep the car in a straight line.
As an off the wall suggestion,a worn LH rear beam bush would cause rear wheel steering to the left,but it would make one hell of a racket with the play.
We know the RHF braking does not match the left,I`ve not encountered a collapsed flexi brake hose,bulging and burst ones yes,so I await the outcome of it`s replacement.
I` be pissed if I had replaced everything you have,and was still having problems.
Merry Christmas.

 

[STEVE.M]

I found this really helpfull online article entitled `Pulling you in to brake diagnostics `on `Tomorrow`s tech`site.
Apparently collapsed flexi hoses are more common than I was aware of.

 

[GrahamS]

I found this really helpfull online article entitled `Pulling you in to brake diagnostics `on `Tomorrow`s tech`site.
Apparently collapsed flexi hoses are more common than I was aware of.

Thanks for all the info Steve, hope you had a good Christmas. I read that article on Tomorros Tech as well and it's what got me looking down the brake line route.

I originally had eibach prokit but have now changed to sportlines and the problem persists. All tyres are correctly inflated. Before changing the rear beam to a disc one I checked the bushes and they seemed tight. There isn't any play there at the moment having had a good wiggle on it earlier.

When I changed the piston I did notice a little bit of debris in the caliper so I think that maybe the rubber line disintegrating. That's what I'm telling myself anyway! Braided front lines on the way, will fit Tuesday evening and report back. Driving to the lake district on Thursday so hope to have it sorted by then, otherwise we'll have to take Lauren's Clio which is similar to driving a sponge.

 

[GrahamS]

So, braided brake lines on the front, still doing exactly the same thing. Will put it on the brake machine again tomorrow to see if it's any better. I'm starting to loose hope with the stupid car now

 

[STEVE.M]

So, braided brake lines on the front, still doing exactly the same thing. Will put it on the brake machine again tomorrow to see if it's any better. I'm starting to loose hope with the stupid car now 😧

ashley_t has an ABS pump unit up for sale for £10,but rag the hell out of the pads first,as per my PM suggestion .
J14 on M1 to MK city centre and back is a good place to do that.

 

[GrahamS]

SOLVED!!!


I got fed up with the problem in the end, popped it in the garage (which I have never done) and due to the joy of having a ramp and being able to look from underneath they found the O/S arb bracket was missing.

I've fitted the new one this morning and the car now brakes exactly as it should. The movement in the wishbone must have been causing the different readings on the brake machine and moving the hub enough to cause the steering problems.

A big thanks to @STEVE.M for all the advice he's given and @Kelv for sorting me for the part so quickly.

And here's the remanence of the old one, it had snapped clean off.

 

[George@RTR_Parts]

Glad you got sorted :up: