Brake bias valve

[MikeB]

What is the current thinking with rear brake bias?
I guess this is a pre IVA post IVA question also.

1. No bias valve, would this fail IVA and cause rears to lock first
2. Use the sierra bias valve thingy (doesn't this change the pressure based on long g so has to be mounted at the right angle to the chassis etc)
3. adjustable bia bar for twin master cylinders (has to be locked for IVA)
4. pressure reducer like this http://cgi.ebay.co.uk/Adjustable-Bra...item19c5576fd5 would this have to be locked or hidden for IVA. It could be neatly installed in the transmission tunel though with adjuster behind the gear lever.
5. What are the other options

Mike

[ozzy1]

1. disk or drum? people have used fiesta rear cylinders i think to alter this.
2. correct.have a look on enochs site.
3. correct.has to be a permanent lock i believe.
4. the inspector will look underneath your car so may be obvious.

[MikeB]

I'm on drums
I'm guessing any adjustable valve with fail IVA is this correct?

[ozzy1]

I think people have used the fiesta rear wheel cylinders on the sierra rears as this reduces the pressure to the rear and prevents them from locking first.I think AshG did this and passed IVA.Maybe check his build blog?

[davedew]

Mike,

If using the Sierra brake system with drums at the back you can throw the deceleration valve away.

Get some VWC345 wheel cylinders from your local autofactors, which are 19.05mm bore instead of the 22mm bore fitted to the Sierra as standard, and the braking system will be fine.

This is how Gus's brakes are done and it passed IVA fine.

Hope that helps.

Dave

[mark]

My car passed iva fine with standard sierra drums at the back with no bias valve to reduce rear effort

All parts were brand new execept the m/c and the rear drum back plates

The rear was one pipe with a t piece to each drum

The tester siad the car was well within spec and a few times i have locked them up on purpose in real world conditions with to see what would happen with weight transfer etc and the rears never lock first

Its strange how some peoples cars need reduced pressure to the rear to pass and others dont

Spud passed sva with the same setup

[baz-r]

been in my local iva station today to check today as i wanted it from the horses mouth
ajustable bias has to be locked with somthing like lock wire and a sticker saying not to ajust it near the master cyl and set in its correct position at time of iva. same kind of affair for hyd ajusters.
also pointed out as long as min to max ajustment would would be within spec then would be no reason to fail it but this would be highly unlightly and ajustment would be only a very small amount.
the guy also pointed out that thease are also not alowed for any car used on the road.

[flyerncle]

Could be wrong but I think Spuds are 10 in drums as are the pair I have for mine.