Brake question

[Remote]

I've recently fitted a few parts to a vts track project

Refurbed axle
266 set up
GAZ coilovers

After these were fitted I've noticed a couple of times when braking hard that the rear moves around a bit, this is not ideal, it actually locks up even though the car is supposed to have ABS. I'm not bothered not running ABS but I'm surprised the rear locks up before the front. Has anybody any ideas on how to cure this??

The front pads are Ferodo 2500 and the rears are new Bosche standard pads.

Do I need a brake bias kit??

I have a track day coming up in three weeks and want to try sort this.

Thanks

[Remote]

Anybody??

[DanTvts]

Checked your load sensing valve is adjusted correctly? Common issue (usually seized as people never lubricate/check them)
This thread explains what and where it is
http://www.saxperience.com/forum/sho...d.php?t=342694

[MartinObviously]

Originally Posted by Remote

I've recently fitted a few parts to a vts track project

Refurbed axle
266 set up
GAZ coilovers

After these were fitted I've noticed a couple of times when braking hard that the rear moves around a bit, this is not ideal, it actually locks up even though the car is supposed to have ABS. I'm not bothered not running ABS but I'm surprised the rear locks up before the front. Has anybody any ideas on how to cure this??

The front pads are Ferodo 2500 and the rears are new Bosche standard pads.

Do I need a brake bias kit??

I have a track day coming up in three weeks and want to try sort this.

Thanks

As above, your rear compensator valve is probably jammed. You can remove it and fit a manual bias valve. costs peanuts and a bit of time for flaring pipes.

Naturally, the back end will want to step out a bit when you fit larger brakes on the front as you're putting more braking effort to the front.

Your ABS won't work correctly as the accumulator cannot relieve all the pressure in the calipers as they have a larger capacity of fluid than standard. You might find the ABS motor will run, but the wheels can still lock up. That's how it is on my GTI.

you should be doing most of your braking before a corner, so the back end shouldn't step out anyway.

[Remote]

Cheers,

Il get looking into that.

Have a good weekend

[Hardrive]

http://www.youtube.com/watch?v=MsyuN-Jflu4&sns=em

Have a look at this link. It's the brake bias valve

[axsaxoman]

you can,t use a bias valve with abs --it wont, work correctly and ideal brake set-up is backs locking very very fractionally before fronts --car shouls squat on braking --not dive at front
remove the abs totally if using a bias valve

[Mike1994]

Cars with ABS dont have a rear bias valve hence why you can fail an MOT for having the ABS light on but cant fail for not having ABS at all. This is because it gives even brake load to the back and front which is going to lock the back end up to to the lack of wait on the end. Im not sure how it works with ABS but no valve on the back.

You might as well run ABS as it should never come on unless you f**k up

[MartinObviously]

Originally Posted by Mike1994

Cars with ABS dont have a rear bias valve hence why you can fail an MOT for having the ABS light on but cant fail for not having ABS at all. This is because it gives even brake load to the back and front which is going to lock the back end up to to the lack of wait on the end. Im not sure how it works with ABS but no valve on the back.

You might as well run ABS as it should never come on unless you f**k up

What? Saxo/106's with ABS all have brake load compensator valves.

You don't have to fsck up for ABS to kick in. I have mine come on quite often because of the roads I drive on. recently my ABS has stopped working and I've had the back end lock up a few times and the car squirms a lot more in the wet.


Anyways, my understanding is this:

With no valve on the back, full pressure would be going to the rear brakes when you brake hard. They will lock up very fast compared to the front which will cause the ABS pump to start, so you won't be able to slow down as fast because the ABS will reduce brake pressure to the calipers as soon as the rear wheels lock up.

the ABS should still work with a manual bias valve(s) after all the standard valve adjusts bias depending on the ride height and hence weight in the back. so fitting a manual one will be fine if you know how your car will be driven. If you set it up with the car empty, it should be ok with weight in it. As pointed out, it'll nose dive though if you have to brake hard.

I'd be removing the pump completely though, it's a pain in the arse anyway on a 106/saxo. I'll probably be taking mine off when I change my axle in the summer.