givemethebighammer
|
| posted on 21/3/04 at 09:05 PM |
|
|
Fiat Uno brake bias valve
Has anyone been through the SVA with a Fiat Uno brake bias valve fitted.
Where did you set it ?
Based on the fact that the valve increases the pressure to the rear by pushing the piston in, I reckon that it should be possible to remove the
adjuster bolt we have all made. This would ensure that the least possible pressure was reaching the rear wheels, so hopefully they won't lock
before the fronts ?
Also no bolt = not adjustable so no issue with having to weld it shut etc
Or am I completely wrong ?
|
|
|
|
|
Mk-Ninja
|
| posted on 21/3/04 at 10:04 PM |
|
|
Your best setting it up on a rolling road on an MOT test.
I'm sure I've got one, just don't know where I've put it
|
|
|
theconrodkid
|
| posted on 21/3/04 at 10:41 PM |
|
|
i set mine at the test station,had to weld it up before my re-test
who cares who wins
pass the pork pies
|
|
|
britishtrident
|
| posted on 22/3/04 at 06:36 AM |
|
|
From experience of these valves on production cars I can tell you the set up is very sensitive, only way is a low speed road test on a dry surface,
roller testing will always give a setting with too much rear brakes.
Start by having too much front brakes and gradually move the setting gradually towards the rear when the rears show first signs of lock backing the
setting off a little to give the correct setting. For SVA you might want to err on the safe side.
These valves were fitted as load sensing valves to a lot of Simca/Chrysler France cars where they were very unreliable it was not unkown for valves
to jamm fully on resulting in an instant spin when the brake was pressed. So if you buy a secondhand one check the piston is operating freely.
|
|
|
givemethebighammer
|
| posted on 22/3/04 at 10:41 PM |
|
|
Got a new one so hopefully all OK.
For SVA you might want to err on the safe side - hence my idea that I should let the valve fully open and fully reduce the pressure to the rear for
the test. Almost no chance of the rear locking up then.
Once the SVA is over I could set the thing up properly as you describe.
thanks
|
|
|
bob
|
| posted on 22/3/04 at 11:28 PM |
|
|
Yep thats my plan too,i'm leaving no adjuster in the uno mount and just going to see what happens.
I expect the retest anyway,so if i have to adjust i can weld it up for 2nd test.
|
|
|
givemethebighammer
|
| posted on 24/3/04 at 04:45 PM |
|
|
thanks Bob glad someone follows my logic !!!
|
|
|
britishtrident
|
| posted on 24/3/04 at 05:43 PM |
|
|
Problen is small front wheel drive cars like the uno run with almost braking effort on the rear all the stooping is done by the front brakes..
Standard Minis once they were a couple of years old used to have only about 10kgf braking on the each rear wheel the inspector could easily fail
you for too little rear brakes.
|
|
|
bob
|
| posted on 24/3/04 at 11:24 PM |
|
|
Not a problem with the rear caliper set up,needs a fair bit of reduction.
I'm thinking the calipers are far too fierce for the - 300 kgs on the rear axle,and the SVA man wants more brakes on the front.
I'll report back after finals,if i'm wrong its not life threatening anyhow
|
|
|
