Eggy
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| posted on 14/2/09 at 07:10 PM |
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Brakes (or the lack of!!)
Ok,
I want to up the braking efficency in the car. Currently the MC is labeled up as Ford KO236 311809 22 Q40 - any ideas what this means and what I need
to change to if I want to improve the feel of the pedal?
Cheers,
Kev.
[img]
 
Master cylinder
[/img]
And any idea what this bit is?
[img]
 
Brake valve??
[/img]
[Edited on 14/2/09 by Eggy]
[Edited on 14/2/09 by Eggy]
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t16turbotone
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| posted on 14/2/09 at 07:57 PM |
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hello, you need to remove that valve on side of MC, and fit fiat uno biasing valve to rear brake line instead
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Eggy
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| posted on 14/2/09 at 08:05 PM |
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What's the valve do?
(Sorry about the image sizes - took me 3 attempts to get them working!!)
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t16turbotone
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| posted on 14/2/09 at 08:10 PM |
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think they call it a q valve, its a special valve which alters pressure to rear brakes depending on g forces, but its set up for sierra weights and
figures, no good to you
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tomblyth
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| posted on 14/2/09 at 08:17 PM |
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it reduces the fluid pressure to the rear wheels so they dont lock up to early, that valve may be ok ! but as surgested there are ways to make it
adjustable . mines a wilwood version but there are various types ! look on ebay for break bias valve,
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Eggy
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| posted on 14/2/09 at 09:58 PM |
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Any ideas on the MC?
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britishtrident
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| posted on 15/2/09 at 09:20 AM |
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From the mounting bolt postions it is clearly a master cylinder designed for use with servo. These have a bigger bore than non-servoed cylinders.
The smaller the master cylinder bore the less pedal pressure is required to stop the car.
You need either a smaller bore master cylinder from a without a servo or you need to fit a servo or fit a balance bar pedal box.
All cars with servos have master cylinders with bores from 0.81" to about 0.93".
Ford typically use 0.81" or 0.83" on medium sized models.
Car without servos have master cylinders sized from around 0.625" to 0.75". Car without servos but with front disc brakes tend to use
master cylinder of 07." or 0.75"
Both Westfield and Caterham use 0.7" master cyliders on the standard models.
The Fiesta Mk1 witou a servo used a 0.7" mastercylinder.
The Cortina Mk3 1300 without a servo used a 0.75" master cylinders.
With a balance bar pedal box cylinders from 0.625" to 0.75" are used depending on size of calipers fitted to the car.
Below the 0.7" Girling cylinder used by both Caterham and Westfield.
[Edited on 15/2/09 by britishtrident]
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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britishtrident
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| posted on 15/2/09 at 09:28 AM |
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The pressure regulating valve in the picture works purely on hydraulic pressure.
As excessive pedal pressure is required to get enough hydraulic pressure in the system stop the car it is probable the valve is having having no
detrimental on the the braking effort --- the hydrualic pressure simply isn't high enough for it to cut in.
[Edited on 15/2/09 by britishtrident]
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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Eggy
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| posted on 21/2/09 at 10:57 AM |
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Many thanks for the replies (sorry it's taken me a while to reply, I've been working in Germany without web access )
So, just to clarify, it's new mc (fiesta or cortina) and the valve from an Uno? (time to break out the credit card)
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britishtrident
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| posted on 21/2/09 at 11:15 AM |
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You don't need the Uno valve
Either retain the existing valve or you could try it without. a vavle fitted.
The rear brakes at best do 25 to 30% of the stopping and I doubt if the valve you have is even cutting in at normal stopping pressures
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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Eggy
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| posted on 7/3/09 at 06:38 PM |
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Many thanks for the help so far but the story continues..........
After a major search I found a Fiesta MC (It was listed as Mk1/2 Fiesta) on Ebay. It arrived yesterday and so, like a kid with a new toy, I rushed to
the garage this morning to fit it......
 
Brake MC
Have I been sent the wrong thing? If not, any ideas which pipes go where and is it ok to blank the spare port off (I've got a single line running
to the rear)?
Not happy - why does everything take so long on these cars?!!! I need a beer!!
[Edited on 7/3/09 by Eggy]
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mistergrumpy
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| posted on 7/3/09 at 09:56 PM |
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I can't see why you couldn't blank one outlet or if not maybe you could tee one outlet into the other. It looks like a dual piston
cylinder and if I were to guess I'd say that one colour was left side braking and one right side braking. So by blocking say yellow rear you
would still have the front left and rights and one rear who's handedness would be irrelevant.
I'd be very interesting on knowing the definitive answer though.
Been doing some reading on this MC and it seems it is like I said, a cross split with a 50/50 balance if I remember. People have suggested putting the
brake light switch into one of the rear holes.
See here
[Edited on 7/3/09 by mistergrumpy]
[Edited on 8/3/09 by mistergrumpy]
[Edited on 8/3/09 by mistergrumpy]
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britishtrident
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| posted on 8/3/09 at 10:13 PM |
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Two bleed nipples is all that is required -- one in a front circuit port and the other in the spare rear circuit port.
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britishtrident
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| posted on 8/3/09 at 10:22 PM |
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Re-readding your last post ---
It might be a idea to measure the bore of the new cylinder before fitting as only a very few Fiestas all of which were poverty spec Mk1 --- most
Mk1 and probably all Mk2 models had servos.
Usually with Girling/Locheed/Lucas cylinders the postion of the mounting holes reveals the cylinder type --- if the line joining the hole centre lines
is vertical then it is a non-servo. On cylinders for direct mounting on the servo the line joining the hole centres was horizontal.
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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MikeRJ
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| posted on 9/3/09 at 10:38 AM |
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quote:
Originally posted by britishtrident
Re-readding your last post ---
It might be a idea to measure the bore of the new cylinder before fitting as only a very few Fiestas all of which were poverty spec Mk1 --- most
Mk1 and probably all Mk2 models had servos.
The presence of the pushrod and rubber dust cover would suggest this isn't designed for a servo?
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mistergrumpy
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| posted on 15/3/09 at 06:13 PM |
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Just to hog this thread a little and to settle it in my mind.
Brake MC
This MC has a 50/50 cross split so am I right in having say both yellows to each of the front wheels and one blue to the rear with a bleed nipple in
the other blue/ The blues are an M12 with a large port whilst the yellows are M10 with a smaller port.
Cheers
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