Mick it isn't the bias valve. the handbrake is your problem. scrapper2 and doogies mk1 are exactly as your describing. ive always wondered if the cylinder on the handbrake is correct and weather or not it should be a different bore size. there isn't alot of pressure needed to lock the rears, but i the cylinder bore is pretty big, so maybe it needs a downsize?

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The handbrake has been in my Cooper S for 6 years now, from memory the brake pedal had about half a inch of travel till hard, aftr the handbrake was fitted it went to about 3/4 to a inch of travel, i think its the same story with Scrapper as well.

Doogie

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Hay, it's not about the car, it's not about the venue, it's about the people that come here. Peter Dwyer, Mayor of Hay NSW.

same here - as I said, I lost about 1/2 and inch of travel, Mick is saying he's lost more like 2 inches

if you have one available, replace the bias valve with a straight through joiner (or a T piece and put a bleeder in the 3rd outlet) and try it without the bias valve - the only difference between your setup and that of my car and the 2 of Doogie is the lack of bias valve

(I believe I'm using the same Landrover 3/4" bore MC as your setup)

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Doogie, Simon,

thanks that is what i was looking for. brakes getting hard 1 inch off the floor is not something i plan on "getting used to".

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

There is no difference in master to caliper ratio you are right.
What you need to understand is that the bore for a specific car's master cylinder is based on achieving X amount of pressure (psi) to the brakes (can be different for front/rears), based on the pedal configuration.

You've changed the pressure to the front/rear brakes by removing the mini rear limiting valve and swapping it for an adjustable tilton brake proportioning valve.

More fluid is going to the rears which means there is further to push the fluid, which is why (in your case) the pedal has longer travel.

Have a look at the graph on the tilton manual - it tells you that from an input of 1200 psi, you can range it from 500 - 1100 psi (41.6% - 91.6%).
It's not 100% adjustable and what I think you are finding is that even at it's lowest setting (41.6%) it is pushing too much fluid to the rear.

Solution - upgrade your master cylinder or add back the original mini rear limiting valve or remove your tilton prop. valve.

I'm about to change master cylinders and add a lever-type tilton prop. valve on my race mini - i'll let you know the results, but I plan to keep the original mini rear valve intact.

My goal is to improve pedal feel with my 4 pots and see if I can improve braking via the prop. valve.

That sounds like the problem, I suppose a quick way to test it would be to fit a small ball bearing into the fitting on the exit of the Tilton valve and see if the pedal suddenly gets better.

been talking to a local about the 1275GT racer who changed the spring in the tilton valve. I think i need to get the details and do the same.

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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