pulling under braking - not caliper

[HazzaCrawf]

Hi all,

Replaced my pads and discs on my 2005 Renault Clio nearly 7k miles ago and all was fine, however during the process of removing the discs I accidentally knocked the caliper from the coil spring and, for a brief moment, the caliper was hanging by its hose although the brakes were still perfect.

Fast forward to now - I had the tracking done a month or two ago; ever since then the car has (ever so slightly and only under heavy-ish braking) pulled ever so slightly to the right each time. Caliper slide pins have been greased when the brakes were replaced and it seems too sudden a problem to be a sticking caliper.

My question is: how likely is it that the flexi-hose has been damaged but only just reared its ugly head?

Is it likely to be suspension or tyre related, bearing in mind the tyres are unevenly worn due to dodgy tracking?

And is there any way of telling if the hose is damaged?

Cheers all,

[HazzaCrawf]

Hammer67 said:

First thing I'd do is check the tyre pressures.

After that I'd strip out the pads from the calipers, check the pistons, slide pins and pads are moving freely, clean everything up, lubricate and reassemble. A sign of a something sticking is unevenly worn pads. They should all have very similar amounts of material left on them.

Anything is possible in 7K miles.

Not much you can do with the brake hoses apart from carefully examining for damage, kinks, splits etc. If in doubt replace them.

Pads are evenly worn on both sides, so as far as I know nothing is sticking. Slide pins also move freely.

[HazzaCrawf]

brrapp said:

Quite likely to be a worn bush on one of the suspension arms. When braking the arm will move slightly back causing the car to 'steer' to that side. If that is the case you might be able to test it if it'steers' the opposite way under hard acceleration

Would a worn suspension bushing be made worse by adjusting the tracking?

[HazzaCrawf]

My first suspicion it will be a worn suspension bush but flexi hoses are cheap and easy to eliminate. I'd fit a pair of those on the front and see how it goes.

Tasmin200 said:

Are you sure your tyres are scrubbed just due to tracking?

Edited by Tasmin200 on Sunday 16th October 21:35

The N/S tyre is worse than the O/S front tyre by a pretty big margin and car pulled to the left (braking or no braking) before tracking was done. Now the tracking/alignment has been fixed, the pulling has stopped and car tracks straight and true, until I brake suddenly or firmly - at which point the car slightly pulls to the right, not a huge amount but certainly noticeable.

[HazzaCrawf]

E-bmw said:

As above definitely not due to the hose or you would see leakage, all the hose does is allow pressure in the system to get to the calliper, so it can't produce the effect you are describing without leaking LOTS!

I thought the inside of the hose could collapse causing a slight restriction? I can't see any kinks or cracks in the hose at all, although I'm not able to see if it has bulged/been damaged in any other way just yet.

[HazzaCrawf]

Hammer67 said:

Clutching at straws there I would have thought. Have you carefully checked the tyre pressures? A slight variation between the 2 tyres could cause this.

It might also be worth swapping the 2 wheels over and seeing if that has any effect on what`s happening.

When is the MOT due? Maybe ask the tester to report back on any play in the bushes/joints on the front suspension.

MOT was done in June, no advisories on suspension of any kind - in fact no advisories at all (not that advisories mean a huge amount).

Given people's responses I am confident it isn't a braking problem - the pads have equal wear on both sides as of a month ago but was panicking due to the 'hose accident', and the pulling only occurred post-tracking. Therefore, I'm thinking that my plan of action should be:

check bushings for play shortly before tyre replacement (tyres are unevenly worn, N/S quite badly so and are nearing wear bars)
replace tyres and have alignment re-done
failing that, replace front brake flexi hoses

[HazzaCrawf]

E-bmw said:

Don't waste your money on changing the hoses, they are NOT the problem!

It could be tyres & as you know there is an issue with their wear, sort that out before going any further, it is most likely to be a calliper issue though, even though you think it may not be. The only other option is a suspension bush/joint.

Never come across a sticking calliper before. The guide pins have been greased - what else could cause the calliper to stick? Worn piston seals, I suppose?

This is my first car that I've owned and maintained for nearly two years, but some problems I just haven't come across yet!

[HazzaCrawf]

one eyed mick said:

In one of your posts you say tyres are unevenly worn THERES YOUR ANSWER !!! get some propertyres on and a full geo check adjust!!!

Would unevenly worn tyres cause it to track straight when not braking, but pull slightly when on the brakes?

SebringMan said:

If the tyres were on before it was tracked that will cause the car to pull.

My Clio did exactly the same when I bought some Turbine wheels for it. 2 new tyres later it was great.

My BMW is tramlining quite a bit at the moment with uneven wear. It would have helped if
-They didn't have 4mm still left on them
-They weren't over £160 a corner! That price is fitted from Black Circles :/.

I'm tempted to change them but with the rear being close to being changed that could be a huge bill for the month!

Did it only pull under braking? The clio tracks perfectly straight when off the brakes even if it feels a bit 'unsteady on its feet'.

[HazzaCrawf]

SebringMan said:

HazzaCrawf said:

Did it only pull under braking? The clio tracks perfectly straight when off the brakes even if it feels a bit 'unsteady on its feet'.

Ah, yes, good point!

It pulled pretty much all of the time!

EDIT : I've just seen that you changed the discs and pads. How easy was it to slide the pads in? If it was hard that is almost certainly your problem. If yours has slider plates corrosion and crap builds up beneath them and effective seizes the pads in. In a really bad case they can ruin a perfectly good set of discs prematurely.

How were yours? Mine were terrible despite having new brake discs and pads. With a fully cleaned up caliper carrier with new plates with ceramic brake grease (I've not had much luck with the copper stuff!) all was well.

It details it in my thread . There is an off chance that your brake pipe has become semi blocked but I doubt it.

http://www.pistonheads.com/gassing/topic.asp?h=1&a...

Edited by SebringMan on Monday 24th October 09:37

New brake hardware was fitted and fully lubricated when it was fitted. I also double checked a few weeks ago and pads seemed to move freely with little issue; slider pins have also been greased thoroughly

Thanks to all who have posted by the way:

I'll throw some new tyres on the front and report back...your comments have all been taken into consideration

Thanks guys

[HazzaCrawf]

Hi all,

New tyres were put on the front yesterday - Avon ZV7s because the other two tyres are also Avons and I couldn't have a mismatch! The car feels transformed - a lot steadier on its feet, plus the steering and general road noise is smoother and quieter.

As for the pulling under braking; the tyres appeared to have cured this, although I haven't yet had much chance to test it, but feeling more optimistic! According to the tyre fitter, the old Lanvigator ditchfinders were "fked" and probably produced some odd handling characteristics due to the uneven wear on both sides.

One more thing - I had the tracking re-done because I've had new tyres even though it was already done a couple of months ago. The mechanic noted that the adjuster nut, presumably for the track rod end was seized and sheared one of his spanners in half while trying to loosen it. Surely it wouldn't be seized up again in a few months?

Anyway, I'll do a more thorough road test and confirm that the pulling's stopped. Cheers all!