Switching lines on master cylinder for disc swap

[K85 Octane]

I bought a new MC, something from the late 90's off a truck with rear discs. I can't remember what it's from, but there was a thread about it. I've searched, really I have, but at least it's a simple question.

When installing the new MC, do I swap the brake lines front to rear? Or keep them the same as factory?

'85 blazer

 

[waybad1]

I swapped them front to rear, the lines would only fit that way
on the m/c I had. It worked out great

 

[K85 Octane]

hmmmmm, never took that close a look at the fittings

 

[waybad1]

Every m/c I looked at that had the bigger piston
had the bigger fitting in the rear and I looked for days
I actually didn't want to swap lines, but the pedal was
better than stock after installing a 3/4t master cylinder
and swapping lines

 

[ashman]

hmmmmm, never took that close a look at the fittings

yeah, the fittings are different sizes, so you'll have to swap, or change the fittings on your lines.

when I did the swap on mine I just pulled the lines between the prop valve and MC from a donor truck so I didn't have to rebend them.

 

[Teck]

You can get fitting at the auto parts store that will let you keep the line in the proper place. That is what I did. They screw in to the mc and swap the size back the way they should be. Can get pics later.

 

[4X4HIGH]

Not sure why alot of you guys try swapping in a different master cylinder when doing a rear disc swap. I installed rear disc on my rig about 10-11 years ago and re-used the factory master with no issues.

 

[gotblazers]

Not sure why alot of you guys try swapping in a different master cylinder when doing a rear disc swap. I installed rear disc on my rig about 10-11 years ago and re-used the factory master with no issues.

Did you use any kind of load sensing or proportioning valve or did you just plug the lines straight in to the rear calipers?

 

[4X4HIGH]

Did you use any kind of load sensing or proportioning valve or did you just plug the lines straight in to the rear calipers?

The rear lines came off the wheel cylinders and then went right to the calipers (I did use a short 8" section of steel braided hose so the calipers don't crack the steel line).