Any SVA issues with fitting a proportioning valve for the rear brakes. Is it OK for it to be adjustable from the driving position? I'm thinking of fitting it on the tunnel forward of the gear lever.

from what I have been told it should not be adjustable whilst driving for the SVA

I had a feeling that might be the case.

if you use sierra brakes and a sierra MC you shouldnt need one

If you fit one it needs to be PERMANENTLY locked ie split pin or similar for SVA.

I have one but you won't need it if you use the Sierra M/C, I had it fitted for SVA but it was hidden in the tunnel, as mentioned if it is visible then it must bet locked in position, best thing I would say is not to bother.

Rich.

sorry but what is it about the sierra m/c that is different?

I'm switching to discs at the back from a drum setup & still keeping the original master cylinder. I thought it would be a good way of making sure the backend doesn't lock up first.
However I might bin the idea for now then & think about it again after SVA.

I had sierra discs all round and a Sierra MC I passed my SVA fine

the sierra MC I believe already sends the correct pressure to front and back

thanks.

If using discs u will need one

I used one from a fi at uno and made a bracket and screw up to adjust it,

Tried it fully open (no screw) at sva and it failed

So set adjuster up there (same test) and covered it with araldite there then. They passed it ok as it was not adjustable

Used standard Sierra MC

Hope this helps

[Edited on 16/3/07 by Kev99]

I would just like to confirm I passed my save with standard xr4x4 discs all round
plus cheapo pads and a sierra MC

if you use aftermarket and calipers you may need one but
PS I also had vented discs but this wouldnt make that much of a difference

NO Brake valve needed

I fitted a valave from an Uno to my standard Sierra braking system (rear drums) during the build to save having to install one afterwards if I ended up needing one. Mine's fitted in the engine bay above the m/c using a bracket with a screw and lock nut to provide adjustment.

I used the adjustment to tune the set-up and get the brake balance right, then tacked the locknut to the bracket with a tiny weld so it was locked. SVA man was perfectly happy, but did comment that it would have failed without the weld or something similar in place to lock it.

I used the wilwood valve. It had to be pop riveted to be unadjustable at SVA.
A properly designed prop valve setup will give optimum braking over a wide range of conditions unlike a bias bar which is only optimal for 1.
Here's a link to a spreadsheet I used to design my setup - you can see how the brake force distribution automatically tracks the weight transfer.
There's no doubt that you will pass SVA with stock kit so long as it puts most brake force on the front. Equally there's no doubt in my mind thet a system which performs better in slippery conditions will be safer!!!
cheers
Bob
http://freespace.virgin.net/bob.carter/files/brakecalc.xls
edited because I was barking optimally ;^)

[Edited on 16/3/07 by Bob C]

Another vote for the "You don't need one camp"

SVA is the best place to find out. Virtually no-one passes first time and if it fails because of this then it's a very simple fix.

Taunton and Exeter SVA centers interpret the regs different from the above. You can have an adjustable valve but the brake test will then be done twice, once with the valve adjusted to one extreme and again with it to the other extreme. Which means you will probably fail if the valve works!

Definately - that's why I had to rivet the valve into position once set.
Bob