Pulling right under hard braking

[dan_b]

Hi all
Not been on the forum for a while, much to my disappointment, but well, you know, work etc (and going on holiday and driving an Elise 111S, but that's another matter!)

Driving the S2 around this weekend in spirited fashion, I've noticed a rather unpleasant pulling to the right under hard braking.

I've got Porsche 968CS calipers, 304x30 discs with EBC Reds up front, (pads up front have been on for about 4 months) and just recently installed new rear stock discs and EBC Greens at the back.

I'm using Dot 5.1 fluid, which I've not bled for a while, but it was changed in February.

My question is, what could be causing this? How do I go about tracking down the problem?

[Stick Insect]

My question is, what could be causing this? How do I go about tracking down the problem?

For a start it probably won't be on the RHS of the car. It is probably the left hand caliper not braking enough and the car pulls to the right because the caliper is more powerful.

It may be the sticky pad problem on the split calipers.

Take the wheel off and check the brake pads can be moved easily. If they don't move then find out why.

Another option is very low tyre pressure in one of the tyres.

HTH

David

[Keeper of The Kitten]

I had a very similar problem with my CQ ages ago, but I have a different suggestion:

Try switching off the ABS - my old CQ had a problem with left front sensor. I'm not saying that is the cause, but if you drove it with ABS switched on (no light in dashboard) the car would pull right. Switch ABS off (light on in dashboard) and the car would behave normally. Weird, but worth a try? If it turns out to be a sensor thing, we may have found something interesting!

__MDC__

[porkkis]

If it's not the brakes then it's probably caused by worn suspension bushes in wishbones and/or subframe to body connection. Worn or too soft bushes let the wheel allingnment change under hard forces.

[dan_b]

It feels almost as if the car is twisting from behind - so maybe it's the left rear caliper not gripping as hard as the right? Would that make sense? I did have to replace the caliper dust seal on that one a couple of months ago, so maybe it's sticking as a result of that?

Cheers for the advice!

[Stick Insect]

It feels almost as if the car is twisting from behind - so maybe it's the left rear caliper not gripping as hard as the right? Would that make sense? I did have to replace the caliper dust seal on that one a couple of months ago, so maybe it's sticking as a result of that?

Cheers for the advice!

You haven't still got a clamp on the flexible pipe have you? A neighbour had a bad accident because the garage had left a clamp on his rear flexible!

David

[dan_b]

I don't think so, I'll go and have a look!
I'm pretty certain now that it might be the left rear caliper sticking due to that dust seal splitting. Grr.

[Stick Insect]

I don't think so, I'll go and have a look!
I'm pretty certain now that it might be the left rear caliper sticking due to that dust seal splitting. Grr.

Err It was a joke I'm afraid I have just had to strip down and grease the sliding calipers on the Mondeo to stop them dragging. The braking has improved as a benefit of the less friction to slide the piston across.

Clean, check and grease all the brakes and you may find something.

David

[dan_b]

Well it seems that the rear caliper is ok. What I have found though is that my EBC Reds up front have disintegrated - the pad material has come off the metal backing plate on the left hand side caliper. Bloody hell

I'm chucking these EBCs out and getting Ferrodos up front as soon as I can.