I'm about to make the adjustment bracket and mount the fiat brake bias valve and was considering positioning it so that it was adustable (without tools) from within side the car, so i could easily adjust depending on driving conditions and/or car load. Anyone done this yet? Also how much adjustment and how sensitive (number of turns) are these units, will i be wasting my time?

I have a feeling having it adjustable from the car is an SVA failure point!

Cheers,

James

Is it!!! I will check the manual tonight.

acording to the tester it has to be welded up so it cant be moved after setting on the rollers,but im sure we know how to overcome that in the future

I've fitted mine and it seems really hard to push the plunger into the body. I've had to add extra strengthening to the bracket and it still bends under the strain. Is this normal???

when you use the brake the piston will try to push upwards with fluid pressure,the adjusting bolt is to stop the piston moving up too far,the further up the piston moves the more pressure goes to the rear brakes

The plunger is already in as far as it will go,it comes out under pressure(fluid).

The idea is to stem the flow by holding the plunger in,i hope this is correct as its the only explanation i can come up with this time of night

For all the time and effort involved in fitting a brake bias valve, I would be inclined to get the car through SVA, and then fit the valve afterwards, in a location that suits you.
There's a page on my site about making and fitting a bias valve.

Unfortunatly i need to fit bias for the SVA,with the lightness at rear i cant gauruntee the calipers not locking up.

Thanks chaps, hope I haven't buggered the valve!! That makes much more sense....

i hope so as well jasper me old mate,there are no more in the country

And we are both hungry

I posted this somewhere else so sorry if you've already seen this but, have yo ulooked ubder the bonnet of a Nissan Micra? They have a spring-loaded pressure limiting valve as standard as they are quite light cars (850kg or so I think). It is fitted on the left-hand inner wing and has 2 pipes in and four out, might be worth a look?

This is what we have done (see bottom of page)

bias valve pics

As long as when the bias is set to minimum braking at rear, the rear brakes still work that is OK for SVA (according to the manual)

How are you gonna get the car out of the attic when you've finished?

There is a big hatch in the floor! When i built the F27 there wasn't a hatch, so we had to cut it out to get the thing down

We are planning on getting it up to the stage of putting the bodywork on before we hoist it down and put it in my garage (once it has a new roof and secure doors)

This must win the prize for the strangest build location!

Whats the best way to test the bias? Will they let you set it up at the SVA, i know someone who has a MOT testing station at his van hire place, will their brake testing rollers do?

Is it all SVA passable, someone said that if its adjustable it wont pass?

Thanks

If you can set it up before hand and lock it with a pin or the likes i think it will save you a lot of trouble.

Just fitted one of these valves and need to know what the range of movement of the plunger is from fully closed to the furthest it can move out so that I can fit my adjuster bolt/bracket for maximum adjustment.

Can anyone help?

Cheers,
Matt.

Mine seems to move about 10mm at most,i've got an M8 hex bolt in at the moment.
Havnt got round to the setting up yet

Thanks Bob.

Does the pushrod exert much force on the adjustment bolt? I have mounted mine to the steel bulkhead on my indy which is /slightly/ flexible and I don't want the adjustment to get affected by the panel bending. Photo of my mounting in my archive.

TIA,
Matt.

Have a look in my archive,i have fitted a plate on each side of the bulkhead to stiffen it up a bit.

The SVA man usually gives it a bit of a tug so worth doing.

After testing the brakes on the rollers like at MOT, the SVA inspector drove my car in the car park and did an emergency stop. Unfortunatly the back wheels locked up first and thats a fail. Unscientific maybe,but its the method i'm using to re-set the bias for the re test.




i]Originally posted by greggors84
Whats the best way to test the bias? Will they let you set it up at the SVA, i know someone who has a MOT testing station at his van hire place, will their brake testing rollers do?

Is it all SVA passable, someone said that if its adjustable it wont pass?

Thanks