Markp
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 posted on 16/3/04 at 10:57 PM |
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Another brake question----HELP?
HELP!!!!
I got the Stuart Taylor floor mounted bias bar brake set up, and plumbed it all up, I passed the SVA last May and over the xmas period I decided to do
a little cleaning up
I took all the pedal box out and cleaned it up and put it back together. I have taken the car out for a spin and I'm not happy with the front
brakes, The rear lock up before the front and they seem to lack the pressure required to make them work correctly. I have got the 625 cylinder on
the front and the 750 cylinder on the rear.
Which side should the bias bar be wound to to get full pressure to the front??
Is there any other reason why this could be happening??
Have I got the cylinders on the correct way??
It was all working so well until I decide to mess about.
Any help/advise would be great
Mark.
[Edited on 16/3/04 by Markp]
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Wadders
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| posted on 17/3/04 at 12:00 AM |
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Hi mark
all the bias bar does is push one master cylinder more than the other,this is goverened by screwing the threaded bar in or out, so which way you wind
it to send more pressure to the front depends which way round you have your master cylinders mounted. Are you sure that all the air is bled from the
system? on my car i have to unbolt the calipers & turn them upside down whilst bleeding, to tease all the air out. An eezybleed kit makes this
process much easier.
BTW You have the M/cyl's the correct way round .
Also depends on what calipers you have fitted, i have 4 pots on all corners, and found the bias bar ran out of adjustment before i could stop the rear
locking first, the solution was to fit a fiat uno adjustable valve in the rear line. If all was ok pre strip down, then i would guess you have air in
the fronts.
hope this helps.
Al.
i]Originally posted by Markp
HELP!!!!
I got the Stuart Taylor floor mounted bias bar brake set up, and plumbed it all up, I passed the SVA last May and over the xmas period I decided to do
a little cleaning up
I took all the pedal box out and cleaned it up and put it back together. I have taken the car out for a spin and I'm not happy with the front
brakes, The rear lock up before the front and they seem to lack the pressure required to make them work correctly. I have got the 625 cylinder on
the front and the 750 cylinder on the rear.
Which side should the bias bar be wound to to get full pressure to the front??
Is there any other reason why this could be happening??
Have I got the cylinders on the correct way??
It was all working so well until I decide to mess about.
Any help/advise would be great
Mark.
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jimgiblett
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| posted on 17/3/04 at 09:16 AM |
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This link may help:-
Here
Cheers
Jim
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Markp
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| posted on 17/3/04 at 04:37 PM |
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jimgiblett & Wadders
A big help thanks
Mark
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britishtrident
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| posted on 17/3/04 at 05:44 PM |
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I posted a full description of setting a bias bar a week or so ago --
Th important things
(1) Screwing the pivot towards a cylinder increases the braking at the end the cylinder is connected to.
(2) Do any test in DRY weather at slow speed.
(3) Start with too much front brakes and adjust no more than 1 turn at time towards the rear, re-test after each adjustment
(4) When the rears start to just threaten to lock before the fronts stop and back off the adjustent either 1/2 or 1 full turn towards the front.
(5) Test again at different speeds slow working up the speed range.
Remember
Rear brakes should NEVER lock before the fronts
NEVER ADJUST THE BIAS BAR BY MORE THAN ONE TURN AT A TIME..
For racing only -- in wet weather you can give the bias exactly 1 turn towrds the rear to prevent preamure locking of the front brakes but remember
to put it back afterwards.
[Edited on 17/3/04 by britishtrident]
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britishtrident
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| posted on 17/3/04 at 05:48 PM |
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One other point:
When assembling a balance bar the clearance between the forks and the tube welded to to the pedal should only be about 0.5mm any more clearance and
you have any brakes in the event of a circuit failure, any less and the balance bar won't be free to pivot.
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ady8077
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| posted on 17/3/04 at 07:30 PM |
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Hi all
Rally design sell special washers that fit either side of the bearing to prevent the pivot going too far if one ciruit looses presure
Also if its recomeded to adjust the bias by screwing the push rods in and out, how does the dash mount cable adjusters work?
Adrian
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britishtrident
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| posted on 19/3/04 at 05:36 PM |
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quote:
Originally posted by ady8077
Hi all
Rally design sell special washers that fit either side of the bearing to prevent the pivot going too far if one ciruit looses presure
Also if its recomeded to adjust the bias by screwing the push rods in and out, how does the dash mount cable adjusters work?
Adrian
The push rods are only adjusted to get the correct relationship between peda, pushrod and piston nothing to do with bias.
No need for special washers either as long as the side clearance between the fork and the pedal tube is set to 0.5mm -- 20 thou in old money.
Personally I think bias pedal bars and bias adjuster valves should be banned from road cars they are lethal in the hands of twiddlers. Same also
goes for load sensing vsalves fitted to trhe rear of some vehicles -- if you ever have the misfortune encounter one stuck full on, which more common
than you think you would understand my reasons.
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