Car pulls to the left under braking.

[Trondelond]

I´ve changed my master cylinder to the 1" job that I got from Trip, and routed the brake lines accordingly. However, the ABS light comes on pretty much at once the car starts to roll, and it pulls to the left pretty hard when I brake. The left front wheel locks up quite easily, and the right one doesn´t seem to do much work.
I´ve bled the system thoroughly - the pedal feel was a lot better after that, but it still pulls to the left.

Could this be caused by the ABS light? Would a solution be to just yank the ABS fuse out, perhaps? Input is more than welcome. I can live quite happily without ABS, but I prefer my braking to be straight.

 

[JIMMYBACK]

Sounds like a dodgy Master Cylinder to me or the caliper on the right is seized ;(

 

[Trondelond]

Well, the master cylinder is new, and the calipers are freshly overhauled AP ones, so I am not sure that is the most likely answer. I may pull the caliper off to see. If everything else fails, I´ll have to reinstall the old master cylinder and see, but I hope it doesn´t come to that. Just wondering why the ABS light is on at the same time..

 

[Murff93GTiR]

Is there a bleed nipple on the abs pump on these cars?if not i would take the right caliper off and get someone to slowly press the brake and see if the piston moves.if it does clamp off the left flexi and drive it and brake and see if it pulls to the right.if it does u might still have air in the system.also does ur pedal "fade"

 

[Jon Olds]

Disabled my rally car ABS by pulling the fuse, then the ECU. Brakes are ace, big Ap' s
on the front wilwoods on the back. Pads last no time.....
Jon

 

[JIMMYBACK]

Caught Brake pipe maybe, kinked pipe possibly

 

[Trondelond]

Is there a bleed nipple on the abs pump on these cars?if not i would take the right caliper off and get someone to slowly press the brake and see if the piston moves.if it does clamp off the left flexi and drive it and brake and see if it pulls to the right.if it does u might still have air in the system.also does ur pedal "fade"

Come to think of it, the brakes did slip when I tightened the driveshaft bolt on the right hand side, and not at all on the left. The pedal is rock hard, so I doubt that is the problem. There is another bleed nipple, but that´s virtually inaccessible unfortunately.

Disabled my rally car ABS by pulling the fuse, then the ECU. Brakes are ace, big Ap' s
on the front wilwoods on the back. Pads last no time.....
Jon

I noticed a pretty high wear rate when I took it on track, yes!

Caught Brake pipe maybe, kinked pipe possibly

This might be something.. I will take a closer look!

 

[whytie]

Piece of shit, scrap the fucker

 

[Fast Guy]

I'd say the abs light is coming on because of a problem. The abs light can't cause the problem. It does sound like something wrong with the braking effort on the one side - whether caliper or maybe a contaminated disc/pad/bit of air in that side.

 

[PobodY]

Have you done an ABS fault code test; that might help you work-out where the problem is?

 

[Trondelond]

Piece of shit, scrap the fucker

That was my next suggestion.

I'd say the abs light is coming on because of a problem. The abs light can't cause the problem. It does sound like something wrong with the braking effort on the one side - whether caliper or maybe a contaminated disc/pad/bit of air in that side.

My main concern was that the ABS doohickeys would physically alter the brake balance - not just turn the ABS off, and thus it would be a good idea to remove the ABS fuse. But it did hit me that as the brake balance was off even when the car wasn´t running, the ABS machinery probably isn´t to blame. It´s got to be a physical problem of some sort.

Have you done an ABS fault code test; that might help you work-out where the problem is?

Nope, it´s on today´s todo list! Stay tuned!

And thanks for your input, everyone! <3

 

[Trondelond]

Ok, at least the abs and the leftpulling don´t seem to be related. Changed back to the OE master cylinder, and bled the system - it still pulled to the left. Back to the garage, and got a huge burp from the rear right caliper, and a smaller one from the front. Still locks the front left wheel, but it´s not as pronounced as before. The calipers seem to push the pistons out by an equal distance when they´re removed from the car. Perhaps this is just a bleeding issue, but I don´t think there´s any air left now. I´ll go over the system once more to be sure.

The ABS throws error code 7, which is the right rear sensor. I´m wondering if the abs rings can corrode if the car is left stationary for long? If not, I´m worried that I may have damaged one of the plugs in the engine bay unknowingly. Will have to get the ABS control unit plug off tomorrow and start measuring. I hate troubleshooting electronics.

 

[PobodY]

I think the rings corroding (or just getting clogged-up) would be quite plausible on a car of this age; it might just need a bit of a clean-up.

 

[Trondelond]

...which brings me to another question - and the reason why I didn't clean it yesterday - how do you remove the heat shield?

 

[pulsarboby]

right had this before trond

you have obviously lost the fluid to entire system so it will be air trapped in the proportioning valve.
ideally what you need is a power bleeder to force the air back out as opposed to pumping it out as the air bubble tends to go back and forth remaining in the system.

its obviously the r/h caliper thats the culprit so loosen the bleed nipples buy a litre of fluid and just keep pumping it through that side as fast as you can press the pedal then when fluid starts dropping in master reservoir have someone there to continuously top it up.
if you have flexi lines on any of the other pipes then clamp all 3 off so your bleeding the entire fluid through that one caliper.

as for the abs.......bin it as its crap anyway, especially for track use.
if you wanna do the job properly then fit a single brake proportioning valve and bin the pump and everything else (got one in stock if needed)

 

[Trondelond]

It's very hard to disagree with your reasoning here! You know what - I'm just gonna go buy a powerbleeder thing. It'll save me a lot of hassle later, as I don't need someone to operate the brake pedal then.

Binning the ABS is unfortunately not an option as of yet. Thanks!

 

[pulsarboby]

yeah there handy bits of kit especially if you gotta do stuff like that on your own.
the systems under constant pressure that way so much easier to bleed.

trouble with pedal bleeding is that on some cars air just bounces back and forth if the entire system was emptied so you need to force it out under constant pressure. so it cant get caught in things like proportioning valve

 

[jambo_gtir]

No one has mentioned the ABS sensor? If the sensor is fooked, the ABS may think the wheel isn't turning so it applies less braking force to it. Would explain why the ABS light comes on once the car is moving as it can see 1 wheel locked and the others turning....... just a thought.

 

[Trondelond]

yeah there handy bits of kit especially if you gotta do stuff like that on your own.
the systems under constant pressure that way so much easier to bleed.

trouble with pedal bleeding is that on some cars air just bounces back and forth if the entire system was emptied so you need to force it out under constant pressure. so it cant get caught in things like proportioning valve

I've always wanted one, this is the perfect excuse! Will try it tonight!

No one has mentioned the ABS sensor? If the sensor is fooked, the ABS may think the wheel isn't turning so it applies less braking force to it. Would explain why the ABS light comes on once the car is moving as it can see 1 wheel locked and the others turning....... just a thought.

I thought it could have to do with the ABS as well, but I have the same problem if the ignition is off.

 

[JIMMYBACK]

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