Brake Line Blew Out looking for info

[black90sport]

1990 K 1500 RCSB, was driving to lowes at 6am this morning, pulled up to a stop sign. Came to complete stop then BOOM. Could hear and feel it, brake line litterally exploded right under the drivers door. Long story short I want to replace probably all the way from the master cylinder to the rear axle.

1. What size line is it?

2. Are there any connections in the line from the factory? I saw on LMC truck that they sell it in two pieces not sure if it came that way from the factory.

3. Anyone who has had to replace the full run, any tips, tricks, or hints?

I have re-plumbed brake line before but never a full run.

Thanks!

 

[black90sport]

Got the truck up on jacks and started looking at it. I am thinking of plugging the rear brake line at the master cylinder, what would this do? The reason im thinking of doing this is the truck gets driven maybe 3 or 4 times a year when I need to go grab some wood or on a nice day. Now im planning on doing a frame swap and after looking at the brake line it needs to be changed from front to back and its just not worth it when I am actively searching for a 2wd frame.

Does anyone know, besides losing rear brakes, what would happen if i plugged the rear brake line temporarily.

Thanks guys.

 

[df2x4]

Braking performance would be severely compromised. The rears are essentially plugged off right now due to the function of the factory combination valve. If you lose pressure in the rear the combination valve will automatically trip and divert all braking pressure to the front as a safety feature. Plugging the rear lines at the MC would basically give you the same braking performance you have right now.

Personally I would not do what you're describing. Either fix it properly or don't drive the truck. I can tell you from experience driving these behemoths short distances with no rear brakes is not fun.

 

[Urambo Tauro]

I don't remember seeing any connections in the line when I did mine last year. But if it's ever been repaired before, there very well could be. My guess is that pre-bent rear lines come in sections for shipping purposes.

I used NiCopp to make my new line (it's 1/4" BTW), and ran it in one piece all the way to the rear flex hose. I was in the middle of a fuel pump job, so the tank was already out of the way. To maneuver the hard line, I started up front. I measured and duplicated the front bends onto the new line, then fed it up into the engine compartment from underneath the firewall. Once that end was secured in place, I unrolled the rest and cut it to an approximate length. The long, mostly-straight section had to be gently flexed in a long arc so that I could feed it through the rear bracketry before making the last couple of bends in the line.

(BTW, if you're doing the brake line, consider replacing the fuel lines too while you're under there.)

 

[Bob L]

I replaced mine by making it a two piece line. You can bend the front section from master to below door and install then bend the rear section and push it in between frame and fuel tank to under door then just cut to lenth to flare and couple below the door.

 

[black90sport]

I ended up going ahead and cutting out about a 3 foot section that was rough. Everything else looked fine, as the fronts have been replaced and from the gas tank back was redone a few months ago. Like i said ill be swapping to a 2wd frame so my main goal is just keeping it driveable when i want to. Couple of fuel lines did look rough but I am not gonna mess with them until i get heat in my garage.

 

[black90sport]

Braking performance would be severely compromised. The rears are essentially plugged off right now due to the function of the factory combination valve. If you lose pressure in the rear the combination valve will automatically trip and divert all braking pressure to the front as a safety feature. Plugging the rear lines at the MC would basically give you the same braking performance you have right now.

Personally I would not do what you're describing. Either fix it properly or don't drive the truck. I can tell you from experience driving these behemoths short distances with no rear brakes is not fun.

I'm glad you told me not to be lazy. Ended up not being nearly as bad as I thought it would be, just need to bend the new line and put it back together tomorrow. Better safe then sorry and it only ended up being about $7 for the parts.