Bank end twitchy under hard braking

[Dr Forinor 0]

Right, this picture ( http://www.the-corrado.net/.archive/forum/download.php?id=31403 ) inspired me to go out for a very enthusiastic drive, and boy was it fun, I havent had that much fun in a LONG time. Leaving home there were a few silly cars that got in the way but on the way back, an absolutely clear road and boy oh boy oh boy... I'm still grinning, but I could be grinning more!

 

Firstly, I have Avon ZV3s so I know I dont have the best tyre on there (thank fook it was dry), secondly my geometry is out so it wont be handling like it should which I appreciate.

 

But just under hard braking right before a corner, the back end seems to get very twitchy, you have to adjust the steering to keep it in check (I noticed this before I had a bump on the rear axle too). Now I know I need new rear axle bushes, but I just want to know if these shagged bushes are contributing (solely/partly?) to this problem or could it be something else?

[olly elworthy 0]

youre brake compensator is siezed, free it up or replace it and also change them rear beam bushes asap before you do yourself an injury

[Dr Forinor 0]

Can you elaborate on what a "brake compensator" is please? I take it this is different from a "brake bias valve"?

 

Don't worry, I have a date to get these replaced, even have the bushes in the back of the car but I couldnt wait to go for a good drive :oops:

[olly elworthy 0]

its the rear brake bias valve,, different people call it different things,,

[Dr Forinor 0]

So I take it there is less bias to the rear since it's seized? What should the bias be anyway? I heard (or read somewhere?) that if you lower a car, the bias should be changed from the original setting, is this correct?

 

And would the fecked rear bushes be adding to the twitching problem do you know?

 

Thanks for the help mate

[olly elworthy 0]

nah more bias to the rear hence your weaving about under breaking,,

 

yeah teh fecked bushes will give you a kinda pendulum affect as when you steer the car will move about on the bushes also,,

[Dr Forinor 0]

Cool cool, thanks for the replies :)

[olly elworthy 0]

no problem, hope you get it sorted

[Dr Forinor 0]

I'll defo be gettin the rear bushes replaced within the next month or so anyway so thats ok.

 

The brake bias valve, is freeing it up as good as getting a new one? I might actually have to buy a new one, (I need to replace the rear axle and I've heard that the bias valve might need replacing as a result), and is VW the only place to get it? I ask 'cos I just checked and its £75 + VAT from the stealers.

[olly elworthy 0]

you can get it from ECP,, i posted up teh part number and price the other week,, if you do a quick search you should find it,,

[Dr Forinor 0]

Searched, double checked and ordered, thank you olly :)

[olly elworthy 0]

no problem,,

[Supercharged 2]

You'll need a new valve with the axle bushes anyway as it needs to be cut off... the bushes will make a huge difference if the car has done over 100k's

[Dr Forinor 0]

The car has "only" done 69k, just reached 69 yesterday in fact, but given that it's more than 10yrs old, I'll assume that the bushes have perished with age aswell...

[24V Renshaw 0]

Dr.Forinor - Have you had you car lowered (look at your piccy I would say you have) If so the bias valve may not be seized but just needs adjusting.

Basically when you lower the car the valve will apply more force to the rear brakes as it thinks there is more weight in there (suspension sitting lower). If you have lowered the car without adjusting the valve this will cause more force to the rear hence the twitchy, locking up rear end.

Basically get under the back of the car (with it still on the floor or on ramps)and have a look up just infront of the rear beam on the passenger side.

There is a plunger device with a wire hoop which is bolted to a bracket on the subframe. Undo that clamp bolt and allow the pressure to release on the plunger. The unit may be seized in which case that plunger will not move.

 

As for having to "cut it off?" not sure what Supercharged means by that, it all just unbolts....

 

Jay

[Timo. 0]

Often the bolts on the rear bias valve are seized on and 'cutting it off' is the only option.

 

T.

[andy 0]

As for having to "cut it off?" not sure what Supercharged means by that, it all just unbolts....

Jay

hehe if only....