Question about disk convertion!

[Cris.sanchez3]

Ok so I finally ordered my front disk convertion kit, my question is do I need to install a proportioning valve the lmc catalog said if you switch then you need to install it in line with the rear brakes, if i do need it where exactly would i have to put it? I am already gonna instal a new master cylinder cus I know that it's a different one when running front disks. Any input will greatly be appreciated. Thanks!!!
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[jocko]

you will need a DISK brake master cylinder AND a DISK brake proportioning valve. It's not necessarily installed in line with the REAR brakes only - it is connected to the master cylinder and both the front and rear reservoir lines will pass through the prop valve and front and rear lines will exit the prop valve enroute to the front or rear brakes themselves. Make sure to order as appropriate for 1/2 or 3/4 ton - whichever your truck is. For the layout of the lines - google this forum with the search tool at the upper right of each page and reference the zillions of brake mc + prop valve pics on here. 1/2 and 3/4 are different. I try to use factory gm stuff as much as possible, but CPP is a good company also.

[Cris.sanchez3]

In the lmc it says to install this proportioning valve in line with the rear brakes theirs only one in and one out so I'm guessing I just need to install it for the rear brakes
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[PanelDeland]

That's close to the one I'm running.You will need the MC for disc brake.I didn't like it at first,but after some playing around with adjustments it's much better.

[Cris.sanchez3]

So where exactly did you mount it, does it matter where?
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[jocko]

AH, ok, now I understand what you're talking about. This is specifically for a 67-70 conversion - so is it implied that you would be leaving the stock non-disk pressure switch in place(?) Hmm. So, the way I understand this, you simply cut the rear line and insert the switch in its place. I'd do it as near the mc as possible. It's odd to me that real proportioning/combination valve with a built in switch isn't recommended.

[Cris.sanchez3]

Yeah I know I was actually thinking of just getting all the parts for the combination kit but then I saw what that would cost so maybe down the line when I can afford it, the proportioning valve is 30$ so for now that's good!!
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[Rufton]

I did a front disc brake conversion and it worked so well w/o proportioning valve I never installed one. I installed large four piston calipers in the front. The rear doesn't lock w/ aggressive stopping. I tested skidding on gravel road and it did fine. Wet road skidding may be the best way to tune brakes if you have a safe place. If rear brakes have a large piston and good shoes then proportioning valve needed to prevent rear passing front.

[Cris.sanchez3]

Yeah I guess I'll try a couple skid tests before buying the proportioning valve it's kinda crazy thinking about cutting my own brake lines since I'm gonna do the work myself.
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