scutter
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| posted on 6/8/05 at 07:55 AM |
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master cylinder threads + locking
Could anyone tell me the threads for the pistons on Girling brake master cylinders?
OK being a biffon at the mo, I've read all the articles from wilwood and preformance frictions on adjusting the brake Bias bar,
Which is the correct method of setting the bias,is it to adjust the length of the pushrods into the bar or to move the pivot point relative to the
clevises?
Also is roll pinning the locknut an accepted method of locking the single nut on the bar?
May thanks Dan.
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marc n
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| posted on 6/8/05 at 08:01 AM |
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threads are 3/8 ths on the brake pipes and 9/16 on the resevoir pipes
to adjust correctly you are off setting the pushrods from the centre of the pedal, if you have different piston sizes in your master cylinders for
front and rear brakes then you dont need to add much bias to pass sva, after that best bet is to get a dash adjuster so you can dial it in to suit
your driving style
re roll pin for sva
from our experiance this is what they are looking for, no splitpins or double lock nuts though
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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scutter
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| posted on 6/8/05 at 08:16 AM |
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Thanks for the quick responce Marc, the thread i'm after is on the pushrod itself(see below).
looks like i'm going to have to buy some more power tools for the SVA test to lock the nut once set.
[img][/img]
Thanks Dan.
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Dick Axtell
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| posted on 6/8/05 at 09:25 AM |
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Hi Scutter,
Just noted your pic. The letters "TVS" stamped on the mcyl body indicate that this unit was produced in India (by TV Sundram, long-time
local partner of Girling).
If the port thread is UNF, then so will be that of the input rod. Possibly 3/16?
Work-in-Progress: Changed to Zetec + T9. Still trying!!
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scutter
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| posted on 6/8/05 at 11:40 AM |
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The picture was for referance only and isn't my cylinders, 5/16 does ring a bell thou.
Dan.
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smart51
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| posted on 6/8/05 at 12:51 PM |
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quote:
Originally posted by marc n
re roll pin for sva
from our experiance this is what they are looking for, no splitpins or double lock nuts though
What is a roll pin? I'll be needing one of these!
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britishtrident
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| posted on 6/8/05 at 03:27 PM |
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Adjusting the push rod length is nothing to do with brake bias --- the pushrods must be adjusted so that the pistons come fully back -- the mushroom
end of the each push rod must clear the end of the master cylinder piston by a tiny ammount otherwise the brakes will bind on as they brake fluid
warms up and expands.
[Edited on 6/8/05 by britishtrident]
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Mix
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| posted on 6/8/05 at 03:51 PM |
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BT
I was under the impression that the length of the two push rods was set so as when the brake pedal was depressed under normal braking the the balance
bar became perpendicular to the push rods.
I agree that the rods should not contact the piston when the pedal is released.
And mine are 5/16 UNF threads
Mick
[Edited on 6/8/05 by Mix]
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scutter
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| posted on 6/8/05 at 04:45 PM |
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Cheers Mick, that's the info i needed.
Dan
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britishtrident
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| posted on 6/8/05 at 08:04 PM |
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quote:
Originally posted by Mix
BT
I was under the impression that the length of the two push rods was set so as when the brake pedal was depressed under normal braking the the balance
bar became perpendicular to the push rods.
I agree that the rods should not contact the piston when the pedal is released.
And mine are 5/16 UNF threads
Mick
[Edited on 6/8/05 by Mix]
Above all the pushrods MUST come fully back so the head of the mushroom comes hard against the end stop washer, if it dosen't you get hydraulic
lock and major brake problems as soon as the system warms up. If there is no other pedal stop (or mechanical stop light switch) fitted a few mm by
that I mean no more than 3 or 4 difference in length between the pushrods won't make much difference but this is also limmited by the side
clearance between the yokes and the tube on the pedal. This side clearance should be set quite small to give a reserve brake in the event of a single
circuit hydraulic failure.
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britishtrident
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| posted on 6/8/05 at 08:21 PM |
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I might add that brake bias shouldn't be twiddled with on a road or competition car. On road car it should be set on on a dry well surfaced road
and left. On a competition car the difference between wet and dry settings is normally no more than one full turn towards the rear in the wet --
usually on a car with discs all round 1/2 turn is enough.
In all conditions the front should always lock a fraction before the rears because nothing will spin a car into the galvanised quicker, even Schumy
runs with bias towards the front.
If the balance bar setting is found is well off centre it is time to think about either changing the size of a master cylinder on one circuit or
alternatively changing the wheel cylinder /caliper bore.
[Edited on 6/8/05 by britishtrident]
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Mix
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| posted on 7/8/05 at 08:22 AM |
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Here's a link which will explain things beeter than I
Mick
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