for those of you who helped or followed my previous thread about my brake conversion.....

ive overcome my problem of having no pressure in my brake system by replacing the master...

i now have a new JB1289 master cylinder in the ute... but i have gone from one extreme to another...

my brakes are dragging quite a bit...
front and rear... calipers arent stuck and everything seems to be fine...

when i crack the bleed valves on the master the brakes no longer drag.... bleed them up.. and its dragging...

could it be that my standard 1200 pedal pushrod is holding the brakes on slightly?
(i wasnt given a pushrod as its part of the booster assembly for that master)

any other suggestion for me to think about as i try to nut it out tomorrow after work?

apololgy's for the long post...
and thanks in advance

check the little knob that is used to set the free play isn't wound out too far pushing the pedal and hence the brakes on and also wind the push rod in making it shorter it will drop your pedal a bit but these two might solve your problem

Yes the original pushrod is holding the brakes on
The JB1289 usually sits on a booster
Your old cylinder has the wrong rod length and has a captive ball (I assume)
You need a different rod to suit your new master

thats right dattoman,

is there another pushrod that can be used successfully with my new master off another vehicle?

or do i need to fabricate or modify my original?

You need to fabricate a new one

Copy it off Dodgeman. I just sent him one to suit his JB1289 onto 1000.

after making a pushrod to suit... i found that the jb1289 master does not seal when the piston is at all the way out (ie resting against the circlip)

if i adjust the brake pedal inward the master would then hold pressure in the brake system.. but again make the brakes drag....
and i couldnt find a happy medium.. as i wound the pedal out until the brakes no longer dragged the brake pedal again became lifeless.... no brakes at all...

obviously this would'nt happen with a booster as it would all be air tight within the booster itself...

but it looks as though i mite be going back to an original master cyl.

At rest with the pedal in the relaxed position the pushrod should just touch the piston. Not preload and hold it down any.
Should have 0 or at most 20 though (.5mm) freeplay.

Booster will have no effect on this even if you had one as there is no vaccuum effect on the pushrod. There is a front seal on the booster to keep the air out.

yeah thats how i had it set up with the new pushrod...

but it wont seal 'unless' i preload it! (just the way it was with the wrong pushrod)
which doesnt help cos the brakes drag...

and it wasnt faulty becuase i changed it for another and its doing the same..

may be a design fault in the aftermarket cylinders perhaps

What do you mean by it won't seal ?

Do you mean its leaking or you have a low pedal ?

i mean the master cyl. sucks air when the piston doesnt have any preload...

to the point where there is no brakes at all... the fluid even overflows..

if u preload it slightly... it works perfectly... keeping pressure and brakes operating as normal.. except for the fact that they drag...
which means its useless to me...