Brake Bias Valve

[Guest kleighton]

Good morning all,

 

I've just about finished my car now and was wondering about needing a brake bias valve. I've not fitted one as yet and was wondering if theyre needed.

 

I understand that the rear wheels could lock up and the bias valve can remedy this, but is it essential for the IVA ? Does this all depend on whether my rear wheels lock up or not, I've not had the opportunity to try it yet

 

Is there a particular valve that's recommended (I'm using 8(6?) mm copper) ?

 

Thanks for any replies in advance,

 

Keith

[Mitch]

Hi Keith,

 

no bias valve not needed, Have you got normal brake set up or you using disk front and back?

 

Sounds like a pre iva visit is needed,

 

Mitch

[Guest kleighton]

Hey Mitch,

 

It's the normal setup, discs front and drums rear.

 

Aye, you're welcome any time, just let me know.....

 

Cheers

 

Keith

[megadodo]

My understanding of the new test is that all 4 wheels are brake tested at the same time specifically to check for rear wheel lock up so I would recommend that you fit it. For your own personal saftey I would also suggest that you want your rear brakes to help in slowing you down and NOT locking up which can cause loss of control.

[Guest peter2b2002]

it's a good idea to fit one, the rear wheels will lock up , I had to adjust my bias valve as the rears locked up at the SVA test, (front disks rear drums 2b+)

peter2b

[Longboarder]

Anyone read the IVA manual? Manually variable bias valves and bars are hardly flavour of the month.

 

Nigel

[Guest Alan_builder]

Oh! Boys!

 

I think Nigel is correct.

 

Peter and Megadodo, Oh NO!

 

The Sierra braking system was designed for a Sierra, front to back weight 70:30. The Robin hood is 50:50. The brake reducing valve is fitted to stop the sierra locking it rear brakes. On my 2B and Dannies with our rear drums we need more rear braking not less due to the different weight distribution. Chuck the ball bearing thing that mounts at an angle away.

 

I have just got a Sierra 4x4 rear end for LSD and rear disc brakes to improve the rear end braking.

 

As it is Danny and I lock the front end up and the backs don't do much. Wet Road and high speed and it is nasty!!!!!!!

 

Peter I don't know why yours is different it should be the same as ours for the technical reason above re the weight distribution. I can only think the front brakes are down on performance. SVA never used to test front to rear balance other than the tester driving it round the block and stamping on the brakes. I don't know how you can get differing wheel base lengths into brake testers so I suspect IVA is the same. Only a calculation is made to see that front and rears have an efficiency for the weight, that is not a balance when you put your foot down!

 

I my

[Guest mower man]

Never had one,don't realy want one ,can't see the need for one , the regulator I use is between my ears, if you are locking rears up in my opinion you have a problem in the system somewhere Ihave done 28k + miles and I'm happy with the set up of 280 mm vented discs 4 pot Hi Spec calipers with their recomended pads std rear drums with std linings and all pipes are s/s braided HTH keep at it keith were the carpets ok ? regards mower man

[Guest Alan_builder]

Never had one,don't realy want one ,can't see the need for one , the regulator I use is between my ears, if you are locking rears up

 

Please read the posts!

 

in my opinion you have a problem in the system somewhere Ihave done 28k + miles and I'm happy with the set up of 280 mm vented discs 4 pot Hi Spec calipers with their recomended pads std rear drums with std linings and all pipes are s/s braided HTH keep at it keith were the carpets ok ? regards mower man

 

Sierra front discs are 240mm single pot with slider, totally different from your set up!

My car and Dan's and I believe Daz393 all lock the front brakes too early!

 

Part of the problem may be due to grabbing, these front discs have very little.... between being just on and fully on with growing brake pressure, your front discs have a better pressure / brake characteristic, simply put you get what you pay for.

 

The post is about the pressure regulator and not your system. Sorry if you find this offensive!

 

I my

[speedtripledan]

I,ve just converted my drum back end to disc for the above reasons fronts lock up backs do sod all. Hopefully i will have more backs now if they lock 1st i will play with bias if they don,t bonus. will find out in couple of weeks.

[Guest gdc]

hi i run wilwood 4 pots on the front with escort drums on the rear .

i have recently fitted a bias peddle box and with no bias valve find the set up fine .

dans runs discs on the front and sierra drums on the rear with no bias valve and also passed sva and is fine .

as said i dont think it is needed .

 

graham

[Guest Alan_builder]

hi i run wilwood 4 pots on the front

 

Totally changes the braking dynamics and irrelevant to the original post!

Just wish I had £400 for the front brakes!

 

i have recently fitted a bias peddle box and with no bias valve

 

Why would you fit a bias pedal box and a bias valve? They do the same job but one is fixed and the other adjustable.

 

with no bias valve find the set up fine .

 

That is what the customer wanted to hear

 

dans runs discs on the front

 

Sierra or Willwood?. Oh and that is not Danny Aldridge

 

and sierra drums on the rear with no bias valve and also passed sva and is fine .

as said i dont think it is needed .

 

graham

 

So why would it not pass SVA?

 

I my

[Guest gdc]

Totally changes the braking dynamics and irrelevant to the original post!

Just wish I had £400 for the front brakes!

 

 

 

Why would you fit a bias pedal box and a bias valve? They do the same job but one is fixed and the other adjustable.

 

 

 

That is what the customer wanted to hear

 

 

 

Sierra or Willwood?. Oh and that is not Danny Aldridge

 

 

 

So why would it not pass SVA?

 

I my

ok so the wilwoods were £230

i have build 7 sevens only the first had the bias valve as fitted by henry .so why have a pop at me i was only trying to help ?

the first was a 2b with pillars and i did as i was instructed by the videos and fitted the bias valve .

it is not needed on a seven as said the weight distribution is far different to a sierra .

and dan, is dan dan he has another lightweight built by me !my son in law .

i had the origonal lightweight pedle box with no bias valve for arround 18 months before deciding to fit the floor mounted set up .

with no bias valve .yes i have the adjustable set up now , but that is for my own choice of set up , an adjustable set up will not pass iva

mayby i didnt make myself clear ,

i am not saying that the ford bias valve will not pass iva , what i am saying is you dont need it , please read

carefully before commenting .

by the way anyone taking part in an sva or iva will know that the brake test takes place on a static rolling road

so the propertioning valve will not take effect , as it is actioned under braking force only .

 

graham

[steve in stockport]

Well we finally got there in the end, as Graham says the brake proportioning valve fitted to the sierra won't work on the rolling road brake tester at the IVA.

 

I've run with the valve when the pinto was in and without since installing the vauxhall, standard sierra disc and drum brakes, never managed to lock the rear end up, with or without the valve.

[Guest Alan_builder]

Well we finally got there in the end, as Graham says the brake proportioning valve fitted to the sierra won't work on the rolling road brake tester at the IVA.

 

I've run with the valve when the pinto was in and without since installing the vauxhall, standard sierra disc and drum brakes, never managed to lock the rear end up, with or without the valve.

 

Steve - its the front brakes that lock up not thr rear, Mowerman introduced the locking of the rear. You are correct with the rolling road & IVA. After IVA on the road if one is fitted your car is danerious due to the reduced braking under -ve acceleration and the bias valve working.

 

The problem the newby had was should he fit the valve or not?

Having been told yes and then no and the yes twice, serious qualification was needed.

Changing the problem from front to back or back to front was no help b y mowerman.

 

Some times KIS is better (Keep it simple or better still KISS - keep it simple stupid) Too often it seems people who don't know advise wrong.