I need to replace the brake bias valve mounted in the rear sub frame and it was suggested that I should fit an adjustable one but they're not cheap nor easy to find $195 from minisport . They're cheaper in the UK but they're out of stock and have been for a while now, then I came across this:

http://www.ebay.com.au/itm/like/Wilwood ... RTM2010730

its $85 delivered and the quality of the Wilwood one would be better wouldn't it, would have to re route the lines and the thread is NPT but no biggy right? what you think?

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Jenk.

Some people in USA have used the Wilwood, it's a proportional valve not a limiting one. But works in a Mini when adjusted correctly.
Can't be adjustable inside car for road use.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

If your brakes are standard you shouldn't need an adjustable one (one would hope they got it right at the factory).

But you can make the standard one adjustable according to david vizard. The mini spares one seems to use a screw pushing a plunger..but I've not pulled it apart to find out what they've done.

Problem with the standard one now is repair kits are NLA. They were made by Lockheed.
Edit, typo

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

looks like they give you a pair of 3/8 24 adapters anyway...

you'll just need to replace the existing valve with a T piece, one the same as on the firewall if you have a spare

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did I tell you that I won a trophy?

I and others including Miniminded in the Netherlands have found that one does not have enough adjustment and/or the spring is too stiff so it does not limit the rear presssure enough. Changing mine back to a standard Mini limiting valve until i have time to make a Vizard style one.

Both the Vizard and Wilwood ones work on the same principal for adjustment - spring rate and length. The stiffer the spring, the higher the pressure in the line needs to be to close the limiting valve and the adjustment of the length of the spring is by winding the screw in and out. But as Doc says, the Wilwood one only gives a proportion of the of the output of the master cylinder pressure based on the adjustment. So if you press the brake really hard, the rears will always get x% of the pressure, as you go harder, they get Y% and so on, which means that you need to have the abosolute minimum proportion with the delivered spring and it still locks up.

The standard Mini ones will increase the rear pressure to a hard limit based on the spring rate and the length. After it reaches that limit, no matter how much harder you press on the brake, the rears get no more pressure, and if you have your sums right, then they won't lock.

Remember that the main reason you have rear brakes in a Mini is to keep the rear of the car from trying to overtake the front. So you only need just enough retardation and not to lock them up.

cheers
michael

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the world is a book, and those who do not travel read only a page
66 Mini Minor sponsored by http://www.lifeonthehedge.com.au/ The Dog Harness Specialists
It was a pleasure ausmini. I'll miss all you misfits and reprobates

Karcraft list a new non-adjustable unit (fitting on rear subframe) but at $235.
What is wrong with your old one? They can be cleaned if that is all that is wrong.
I've seen some that are ok after a very long life down under there.

thanks to all for your input

Bill B the valve sat around for a year after I stripped the car down for resto... thought I would put a seal kit through it before re installing but no seals are available unfortunately.

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Jenk.

The main seal is swaged onto the piston so a kit must include the piston. It isn't a slip-on type seal like everywhere else in a mini. I have removed a piston assembly from a cylinder which from memory appears to be in reusable condition. The body was slightly pitted, making it unserviceable. You are welcome to use it to get you out of trouble.
The original repair kit was p/n GRK6002. Might be available from eBay NOS listings.

If all else fails in getting a repair kit the limit valve is available new. Cooper S is different to standard Mini.

http://minikingdomonline.com.au/product ... -cooper-s/

http://minikingdomonline.com.au/product ... -cooper-s/

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ex-NSW Police 1970 MK II Cooper S
VMCI #43

and the difference is the spring stiffness AFAIK.

_________________
the world is a book, and those who do not travel read only a page
66 Mini Minor sponsored by http://www.lifeonthehedge.com.au/ The Dog Harness Specialists
It was a pleasure ausmini. I'll miss all you misfits and reprobates

Cooper S tax on the spring. It must be made of unobtainium...

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

There is a big difference in the price of the complete limiting valve assembly for Cooper S vs normal mini.
But Mini Spares lists the original spring on its own (27H6620) for 75 pence ("last the AP stock").
Buy the standard valve and the S spring. Easy swap.

"Cooper S TAX" I always find this a little amusing.
I am not 100 % sure what the other Mini parts dealers do, but as far as I know they operate the same way as we do, that is cost plus a minimum mark up,
which does not change because it is a Cooper S part.

However what does not seem to be understood is that we the suppliers pay more for Cooper S parts, and this is often because the Market for " Cooper S specific parts " is less than the general Mini Parts so the production run is smaller so the cost is higher.

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" A Hundred Years From Now It will not Matter what my Bank Acount Was,
The Sort Of House I Lived in, Or The Kind Of Car I drove ... But The World May Be A Better Place
Because I was Once Important In The Life Of A Child"

I don't think anyone is accusing suppliers of inflating the prices of Cooper S parts. It's as you say, and simple supply and demand.

On top of that, a great number on mini drivers will buy to just make things work - very few leyland 998 drivers are going to spend big on OEM or heritage parts when there are other parts around that will work just as well. But if you have a Cooper S, most will do whatever they can to keep it original, which means spending the extra on the original parts instead of generic parts that work.