Board logo

deceleration valve
macspeedy - 17/5/03 at 07:01 PM

On the sierra there is a valve/regulator thing which limits the brake preasure to try and stop the rear wheels locking, I'm reusing this and need to know, which is the in end and out end?

stephen_gusterson - 17/5/03 at 08:48 PM

you need to know more than that.

the valve works on a little ball rolling to close the valve under decelleration. The mounting position and angle of the valve is essential to its working.

Some people have used uno(?) and mini valves as alternatives.

some use nothing.

some use abs and a valve like me. (I mean I use both - im not a valve....)

you could look in a breakers and find the in and out....

atb
steve

geoff shep - 18/5/03 at 10:11 AM

Have you got a Haynes manual? its shown there. What age of Sierra?

Early ones have a cover plate with 3 bolts at front, later ones have a smaller diameter stepped end at the front.

Fluid goes in at the back and out at the front.

I have sierra system in a robin hood with discs front and drums rear and have removed the valve - the fronts still lock first.

Peteff - 18/5/03 at 10:13 AM

Bin it!. The valve has to be set at the angle it is in the saloon and depends on the dive in the suspension to increase the angle. Your car would be scraping the floor at the front to make it work and the back would be six inch off it.

yours, Pete.

macspeedy - 18/5/03 at 11:41 AM

do i need the valve for the SVA?

stephen_gusterson - 18/5/03 at 07:23 PM

only if your car locks up at the back before the front.

there is no requirement for an actual valve - just that the fronts must lock before the rears.

some people dont fit one and get thro sva.

if your car has decent disks on the back it may not........

atb
steve

macspeedy - 18/5/03 at 08:11 PM

its got drums.

Ian Pearson - 18/5/03 at 11:37 PM

You can use an adjustable valve from a Fiat Uno, There is an in line pressure reducer on some Escorts. Not sure which model though.

givemethebighammer - 19/5/03 at 10:03 PM

You can buy the fiat uno item from a place in Bradford 01274 733727 (can't remember the name of the place) the cost about £15. They will do mail order
see Bobs archive for photos. I'll take some pics of mine when it is finished.

Danozeman - 20/5/03 at 06:33 PM

Im not going to bother myself. If your rear drums are adjusted up properly they wont lock before the fronts.. Or the fit the other option of adjustable bias type valve arrangement

Dick Axtell - 22/5/03 at 04:29 PM

quote:
Originally posted by Peteff
Bin it!.


Couldn't agree more!! I used to work on these things, & after much test work, we discovered that the valve closure point was wholly unpredictable. If you hit the brake pedal swiftly enough, this valve can be beaten (i.e. pressure reaches the rear brakes before the valve closes).
If you really want details of this valve, check out the brake files on TOL.
LOL
Dick

macspeedy - 22/5/03 at 07:00 PM

Thanks for all the input, I've decided not to fit it, but will keep it just in case.