Hammerhead
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| posted on 24/6/06 at 03:19 PM |
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Cheap brake bias valve solution
Found this article on blatchat.com
http://members.aol.com/dvandrews/bpvalve.htm
Might be worth a go?
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nitram38
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| posted on 24/6/06 at 03:29 PM |
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Looks like it will be worth a try and only a few quid.
You did n't waste much time finding the article!
Looks like 300mm discs are in!
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Hammerhead
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| posted on 24/6/06 at 03:33 PM |
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britishtrident
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| posted on 24/6/06 at 07:59 PM |
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This mod has been doing the round for 40 odd years, if any of you have old triple C mags from the mid 70s you will find it in an article by Andy
Dawson
I spent a lot of the 1970s and 80s mucking about with these valves and will add three very important caveats.
(1) Standard single circuit Mini valves were set to cut off at a very low hydraulic pressure --- real Minis 60s/70s had sweet FA weight on he rear
wheels and used big bore rear wheel cylinders , the internal spring also have lost any pre-load with age. It was pretty common to roller brake test a
70s Mini with single circuit brakes and only get 10 pounds braking effort from each rear wheel.
(2) To get this mod to work you have to change the internal spring to a shorter but stiffer spring that dosen't become coil bound when you screw
the spring in. The existing spring will only allow a tiny ammount of adjustment.
(3) Always use a new cylinder or a rebuilt one -- if the internal seal fails you are in deep doo-dah.
Thier are much better more modern valves around for example from Fiat, Escort van or Peugeot.
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MikeRJ
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| posted on 24/6/06 at 10:43 PM |
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quote:
Originally posted by britishtrident
(1) Standard single circuit Mini valves were set to cut off at a very low hydraulic pressure --- real Minis 60s/70s had sweet FA weight on he rear
wheels and used big bore rear wheel cylinders , the internal spring also have lost any pre-load with age. It was pretty common to roller brake test a
70s Mini with single circuit brakes and only get 10 pounds braking effort from each rear wheel.
Yep, I can remember testing the brakes on one of the many mini's I had and being able to turn the rear wheels by hand (with a reasonable amount
of effort) with the brake pedal being stood on.
Those valves also used to seize on older mini's resulting in some very interesting braking effects, especialy in the wet. I had one of mine
swap ends at about 15mph so quickly I hardly knew what was happening. Very embarrasing being stopped at a red light facing the queue which should
have been behind you!
Also note that these are not proportioning valves, they simply reach a preset limit then and prevent any further pressure rise, rather than giving
some fraction of the front braking pressure to the rears.
[Edited on 24/6/06 by MikeRJ]
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