Iva Brake Balance Fail 2B 04

[Guest pilswd]

So second IVA and the list has gone from 3 and half pages to 1 main fail

 

"RS21 All wheels of the rear axle(s) must not lock prior to both wheels of the front axle."

 

Dave from Chadderton (good man) rightly concerned about this didn't help that the sump is so low that he had to resort to driving round the test station and unfortunatly as we know Manchester is wet most of the time and she stepped out on the emergancy brake resulting in the above fail.

 

need to get the car back before the end of Nov so have the 2nd Nov booked to avoid a full £450 IVA test.

 

I have the valve fitted at the recommended angle to reduce the presure on the back brakes but still a fail.

 

Any ideas really welcome, but as ever time is limited, have I missed something obvious?

 

Dave

[Bob Tucker]

I assume you fitted the original Sierra balance thingy?

If so, it becomes more effective as it gets to horizontal.

Try dropping the front of it down.

BTW you do have it plumbed in correctly? IIRC it doesnt connect the way you would expect.

Check the Haynes manual for a piccy of the right installation.

 

Les seems to have the answer....

http://www.rhocar.org/index.php?showtopic=23290

 

HTH Bob

[sj-bradley]

Are the brakes / pads / discs new? I.e have they bedded in yet?

 

Do you have drum rear brakes? These will be more efficient from new than front pads until they are bedded in.

 

Of course, these are difficult to bed in if you cannot drive anywhere ...

 

Afraid I cannot help as my system is all round discs and no pressure reducer. Bob is probably the best help though.

 

Simon.

[cb750]

Could you change the valve to a manual adjustment brake bias proportioning valve? You could then adjust it to suit the brakes as they bed in

Rob

[sj-bradley]

Rob,

 

Not allowed under IVA I'm afraid unless the valve is permantly fixed. Same as Bias bars on dual master cylinders. (That's allowed, but must be welded in position - I.e - not adjustable)

 

Simon.

[Guest pilswd]

Thanks for all the feedback I think mine is at the wrong angle, having read the replies not factored in that the front doesn't nose dive like the sierria did so I need to angle it more. BOB you suggest it being almost horizontal?

 

Thanks Dave

[Les Welsher]

you suggest it being almost horizontal

Yes, the ball in the valve when you brake will shoot forward easier at a lesser angle and block off the pressure to the rear brakes preventing them locking.

 

Les

[Bob Tucker]

Just dug out the Haynes manual....

The cover bolts on the end plate must face forwards.

the pipe from the M/C must be connected to the REAR of the valve.

I wouldnt set it horizontal.

Try it half way between where it is now & horizontal to start with.

Make it adjustable so you can fine tune it.

Just to confuse things further....i have disk front drum rear, no balancer, & passed SVA OK.

 

HTH Bob

[Grim]

or just remove the valve completely, very few people have them.

[agent_zed]

or just remove the valve completely, very few people have them.

 

surely this would cause more of a prob as he is trying to get the backs not to lock. I've got the same valve and set slightly flatter than in the sierra. Obv this valve only works whilst moving so no use on a rolling road.

 

The SVA man commented that he was pleased to see that i had put it in correctly as he'd seen them in all sorts of places including horizontal transverse between the axle so that when you went round a corner one way it shut off the rear brakes entirely and the other way not at all ???

 

Not sure how much this would effect but have you checked tyre pressures? just thinking if your rears are a bit hard they are prob going to lock up earlier (is my thinking on this correct? ) most people run around 10-20psi

 

hth

[chris27]

back brake shoes could be too tight to the drums.... try knocking a couple of clicks off the adjusters

[richyb66]

Fiesta bias valve maybe? An easy fit.

 

http://www.rhocar.org/index.php?showtopic=17561&&do=findComment&comment=143381

[Guest pilswd]

Many thanks for all the postings I have realised the valve needs to be near horizontal and that I think I fitted it the wrong way round (numpty) so off to the garage to tinker, thanks again fingers crossed for the 2nd.

 

Dave

[Guest peter2b2002]

this is the second time some one has had this problem , valve should be near horizontal, rear brake pipe comes out the front of the valve, if you make the front mounting bolt hole a slot its easy to adjust the rear lock up point(thats how i did it on my 2b)

peter2b

[edbond]

Have I read somewhere that some people have changed their front pads to more effective ones too?