Brake Propotioning Valve

[MY45]

Ok the problem is that the FJ is locing up the rar wheel before the front coz i put an 80 series master cyclinter in it. is a brake proportioning vavle going to increase power to front brakes nd is this the most effective way of fixing my problem.




Adam

[4sum4]

You can get an adjustable Prop valve,Willwood priced at $170
Or just disk the rears

[MY45]

Thanks go on the net and ordered one from rocket industries for $107. Now fingers are crossed for re-rego

[Josh_GQ]

might be bullsh!t but i'm sure i've beeen told aftermarket prop valves are illegle, so you might run into probs with the rego?
Can anyone verify this?

[cj]

might be bullsh!t but i'm sure i've beeen told aftermarket prop valves are illegle, so you might run into probs with the rego?
Can anyone verify this?

I was also told this but was told that if you adjust to how you need it and then make it non-adjustable, it should be fine. Another thing I have seen on rear discs is to remove some of the pad material to reduce the rear brake efficiency. You could also play around with various combinations of pad materials front and rear, improve the front discs or even put approved braided hose on the front to improve the front brakes.

[bazzle]

HQ holden (from memory) rear prop valve fixes this..

Bazzle

[MY45]

might be bullsh!t but i'm sure i've beeen told aftermarket prop valves are illegle, so you might run into probs with the rego?
Can anyone verify this?

This may be true because in the instructions for the prop valve it said "FOR OFF-ROAD USE ONLY".
I'll let you know how the brakes turn out, and try to post some pics of how its mounted later in the week.

[ozrunner]

I needed to use a Wilwood in addtion to the rear LSPV for my rear disc setup and a respected brake shop advised that they get asked this question often.

If the proportioning valve is located in the cab then it will be deemed illegal but if you put it under the hood you should be fine.

I have yet to put mine over the pits but to be sure I also made a small cover that bolts over the adjuster after its set

JD

[Josh_GQ]

I have yet to put mine over the pits but to be sure I also made a small cover that bolts over the adjuster after its set

i like your idea!

[cj]

Want to make your own brake bias valve? Have a look here:

http://www.rorty-design.com/content/brake_bias.htm

[4sum4]

just remembered that wilwood does a screw down type and a lever type and I think the lever can be removed after its set and they were cheaper to

[Bush65]

[/quote]

I was also told this but was told that if you adjust to how you need it and then make it non-adjustable, it should be fine. Another thing I have seen on rear discs is to remove some of the pad material to reduce the rear brake efficiency. You could also play around with various combinations of pad materials front and rear, improve the front discs or even put approved braided hose on the front to improve the front brakes.[/quote]

This depends where the pad material is removed.

Remove from outer region so that effective radius of the disc is smaller will reduce braking effect.

Remove from the inner region so that effective radius of the disc is larger will increas braking effect.

Doing either of these will probably increase wear rate of pads and disc

[chimpboy]

I was also told this but was told that if you adjust to how you need it and then make it non-adjustable, it should be fine. Another thing I have seen on rear discs is to remove some of the pad material to reduce the rear brake efficiency. You could also play around with various combinations of pad materials front and rear, improve the front discs or even put approved braided hose on the front to improve the front brakes.

This depends where the pad material is removed.

Remove from outer region so that effective radius of the disc is smaller will reduce braking effect.

Remove from the inner region so that effective radius of the disc is larger will increas braking effect.

Doing either of these will probably increase wear rate of pads and disc

I would have just assumed that you'd remove some material from the front or the rearward part of the pad, but no matter where you remove it from it will reduce braking power. Removing some material from the inner part of the pad doesn't increase the effective radius of anything, it just reduces the surface area in contact.

Either way, I can't see any sense in reducing braking power and I think it would be unwise from a legal standpoint as well. A proportioning valve is a much better way to go since when it limits the pressure to the rear brakes, it leaves more pressure to go to the front, which means improved braking power if your rear brakes were locking up before.

I would say a proportioning valve is the second best option here - the best would be to improve the performance of the front brakes.

ymmv.

Jason

[Patroler]

Well i'd have to go with bush 65 on that, if you remove some of the friction material, then it would reduce the surface area sure, but the pressure applied per square centimetre of the pad would be greater - same overall pressure, less area to apply it in, the pads would wear out quicker.
If you removed half of the innermost section of the pad, the brakes would be putting all of their pressure on the outside of the disk, increasing braking.
If you removed it from front or back it probably wouldn't do much except wear out the pads quick.
I'd mount the valve youve got near the master cylinder, out of the way

[J Top]

I assume you have disc brakes on the front and drums on the rear.
Drum brakes are more powerful , till they fade , because they have a self energising effect.
Your original question was how can I make the front brakes more effective.
I have improved front braking in the past by fitting a remote power booster in the front brake circuit , of something like a Tasman or Kimberley or VC Valiant etc.
Rather than reducing braking this increases it
J Top

[big red]

when i put disc brakes on to my EH i used a HQ rear brake line restricter which worked perfectly.
the other way was to change the rear slave cylinders.