Brake line questions

[Overkill67]

Ok so I am running new lines on my 72 C-30 dump truck. The PO has already ripped all the old lines out. rear lines are a no brainer, 1 line from the diff to the prop valve (power disk brakes on the front btw).

So question #1: I understand that the lines to both front calipers need to be equal length, so where was the original mounting of the lines, and is there supposed to be some kind of metering valve or will a standard T connector work just as well.

#2 The master and prop vavle only had 1 line on it (other of course is MIA) It goes from the port on the rear of the master (for the fronts if I am right) to the front top port on the prop valve. Is that correct?

I have done a search already and did not find what I thought might have been in the forums already. Thanks in advance.....oh and I got the camera back from my daughter, but now she cant find the stupid cable to hook it into the puter , so i cant post picks of my beast yet

[Yukon Jack]

Never heard anything about the front lines needing to be equal. Your dealing with hydraulic pressure that doesn't care if the line is 1 foot long or 10 feet long.

As for question #2, is it all drums or disks up front?

[Overkill67]

Thanks, disks up front

[Yukon Jack]

Generally the rear line of the master is for the front brakes. Pop the top, whichever reservoir is larger goes to the front brakes. The prop valve should have one line going to the rear axle and then two lines to feed the front brakes.

[Overkill67]

Thats what I thought, but this prop valve only has 1 for the front and 1 for the rear.

[OLDIRON69]

http://www.lategreatchevy.com/produc...dept%5Fid=1042

your valve should look something like this.

[Overkill67]

nope close but I only have 4 ports on this one 2 on the top on either side of the switch one in the rear and one on the bottom.

[kwmech]

sounds like you have a drum brake prop valve

[Overkill67]

That would be just my luck.......but after looking at some pic's (mainly on ebay) of other trucks with the same setup.....most are 1/2 ton's they look the same.....but the plumbing from the m/c to the valve are all differant lol

[john]

The 1/2 ton's lines run front to front- rear to rear. The 3/4 ton lines are opposite.

[Overkill67]

Ok does anyone know how they ran the line for the right side? I seen somwhere that it was run across the front of the crossmember but looking at the amount of crud on it, that doesn't apear to be right......

[Misled]

***Hijack Alert!!!***
Maybe this will help some others...........

I'm working on a 1970 K20 (drums all around). I converted both front and rear to disks........theoretically, shouldn't I be able to re-use the booster, MC, and prop valve?

I'm sure I'm missing something.....

Thanks for any input!!!

Misled

[Americanrider]

I took these pics a while back, a 71 C-30 I parted out. No longer have the frame or anything. Hope this is what you need.
LL= Large line: Rear brakes
SL=Small line: Front discs

[Overkill67]

Awesome Thanks a ummm a TON lol that is exactly what I needed American.

[Beefcake]

im in the process of doing the same thing.

Is there a cheaper way to go for the proportioning valve? I dont need a fancy on, just on that works.

[OLDIRON69]

Originally Posted by OLDIRON69

http://www.lategreatchevy.com/produc...dept%5Fid=1042

your valve should look something like this.

This is the cheapest one I have found.