Pulling to the right under hard braking

[Krazyken]

Just noticed today that my 1998 MGF Mk1 VVC pulls to the right under hard braking, what are the possible causes of this and could this be improved when the B&G servo bracket finally comes through?

[adrianclifford]

Hi Ken, first of all NO, the bracket will make no difference, it strengthens the bulkhead fixing and stops it from flexing therefore giving the brake fade feel.

Take out the front pads, look at them to see if they are wearing evenly all across, if so clean everything before replacing them. Put copper grease on the BACK of the pad only. Are the discs wearing evenly ?

Does the handbrake work properly, rear calipers are known to seize therefore putting more brake on one side. You will need a rear brake caliper wind back tool to remove and check/clean the rear pads.

Try these before changing anything, it may just be a build up of brake dust.

More remote could be tyre pressure low on one side or an uneven road camber.

[Krazyken]

Hi Adrian

The discs and pads were all new approx 2,000 miles ago, changed for EBC standard discs and Greenstuff pads with copper grease on the back of the pads at time of fitting. The handbrake works fine, 3 notches and its fully on, holding on hills no problem. Tyre pressures are checked every 2 weeks and do not change. In view of this is it most likely to be a sticking rear caliper?

[adrianclifford]

It could be Ken, if you are happy the fronts are working as they should then the rear could be the cause. Look at the handbrake cable adjuster, lift out the ashtray assembly and you will see. Both cables should operate freely together and they should be the same length. If in doubt, securely support the rear and scotch the front wheels release the handbrake and pull it on one notch at a time both wheels should bind together, either first or second click.

If not, did they pull before the fronts were changed ?, then your problem could still lay there.

[Krazyken]

After a thorough check of the braking system everything seems to be working as it should. Could it be a worn suspension bush at the rear? I say rear because the front lower arms have recently been replaced whereas all the bushes on the rear will all be 15 years old now. I have also notice a slight twitch when changing up after hard acceleration or when lifting off in a lower gear when engine revs are higher.

Has anyone had any experience/knowledge of a worn rear bush causing a pull to the right under breaking? With or without the other symptoms above.

[Rob Bell]

Check the suspension for wear - particularly the ball joints and track rod ends. Play in these can lead to some undesirable handling traits. If these are okay, look at the tracking settings - again, if the toe-angles are incorrect, the car can start to veer to one side (4-wheel laser tracking is recommended), but do this after checking simple things like tyre pressures, are the wheel nuts done up to the correct torque and is there evidence of uneven wear across the tyre tread.

[Miccon]

Just a thought..
When was your brake fluid last changed?
If it was some years ago it may have degraded with moisture, which then boils off when heated from braking, reducing the brake effort on one or more calipers and causing an uneven braking effect.

[Krazyken]

Thank you Rob & Miccon for your advice.

All the brake discs, pads & brake fluid have all been replaced with EBC components and DOT 4 fluid in the last 4,000 miles. After fitting new front lower suspension arms due to corrosion I had to slot the offside lower ball joint by 7mm in order to match up the front cambers. After reading previous posts on 4 wheel alignment I decided to set the front toe to 0'00 rather than 10min toe out but left the rear at 10min toe in as per the factory settings. After 4,000 miles on these settings tyre wear appears to be even.

The pull to the right is just initially but as hard braking is maintained the braking levels up. Someone has suggested that as I have slotted the lower front offside ball joint by 7mm in order to match the cambers I may have altered the track/geometry which causes this. Does anyone have a view on this or is it likely to be flex in the original rubber bushes which are now 15 years old? If the rubber bushes are in question, which ones would be the most likely culprits for causing this pull to the right?

[Reckless Rat]

Just wondering... is your suspension ride height correct? This can affect geometry.

[Krazyken]

The suspension height is correct, 368mm @17 deg C all set up with new fluid at MJN Motors, Bristol within the last 6 months.

[Rob Bell]

To state the obvious, something isn't right if the car pulls to one side. This doesn't sound like tram-lining, as I would expect the pull to be to the left rather than right.

Hmm, this is going to need some more thought and checks. Do you know what the thrust angles were when you had your wheel alignment checked?