master cylender dramas. i am changing the front brakes on my 81 1200 ute to disk. do i have to change the master cylender???

not if it already has a tandom master cylinder, one with 2 fluid bottle thingos

just might have to remove the check valve from the front line

Quote: [edit, ... continuing pigdogs reply] ..... which is the rear chamber in the cylinder.

the rear chamber is towards the front of the car

Quote: Thanks for the info but the sentence was intended to be a continuation of the answer provided by Pigdog. This is the reason why there is no question mark at the end of it.
Yes, I should have re-read it & made sure that there could be no confusion. So to clarify, .... the front brakes are run from the rearmost chamber of the master cylinder & the rear brakes from the front chamber.
Sorry 'bout the screw up. I will now edit the offending post to remove confusion.

yeah. my bad.

where exactly is the check valve??

The front one goes to the rear.. I think.... I went disk on mine and had no need to change anything with regard to the master. not even had to add a booster. though I went way overboard on disk size, but hey... every inch counts.

The removal of the check valve is a bit of a misnomer. Sometimes these valves are called residual pressure valves (RPV). And disc alipers have to hold much less residual line pressure compared to drums.

Don't remove anything. If the the calipers are dragging, only then consider removing the RPV.

Sweet. So if I do have to remove this valve, Where exactly is it???