Hard Brake Lines

I'm finally about to swap out the front cross line on my F250. I picked up several sizes on NiCopp straight tubes with pre-installed fittings and flares. My plan is to duplicate the existing piece with the closest length and make it work. This was a much cheaper option than buying decent flaring tools, and I've made it 41 years without having to replace a hard line before.

Any good tips for this process? Mostly I'm thinking of ways to minimize fluid dripping out of the open block connections while I have the line out. I tried tinfoil last time but it didn't help much. I figure someone has done this enough to have picked up a few tricks.

Rubber plug or grommet with a bolt in the middle to stop the leaks while you're working. You're still going to get brake fluid all over you, it's part of the game

yeah, the mess is expected. I'd just like to minimize the air in the system for bleeding.

Are the threads on the fittings standard type? If so I'm thinking a couple 3/8-24 screws with a little teflon tape in place of the tube fitting might work.

i'd just suck all the brake fluid out of the master first. Or, open the bleeders and pump the fluid out with the pedal.

Don't worry about trying to prevent air getting in. Some air will get in, and you will be re-bleeding it all anyway. Plus, now is a really good time for brand new brake fluid!

I use one of the cheap vacuum cap assortments. They work great as plugs and the larger ones can be used for the male lines also. Just move the fitting back and slide one over the hard line.

I just flushed the entire system and replaced the entire front system about 6 months back. Except for this one line. So no need to flush it. Bleeding this thing is a PITA given that it's a diesel and vacuum pump driven, so I want to keep the fluid from siphoning down out of the MC. Minimize the bleed time since running that beast inside my shop is deafening.

I actually found out that the auto parts stores have little brass plugs just for these fittings for a few dollars each. That should do it.

Use a piece of the old bad hard line. Cut the tube about 3" from the fitting, then fold and crimp the cut end. You might want to fold it twice if it cooperates. Then thread the fitting back in hand tight, or just snug with a wrench. If done right it won't leak at all.

Wedge a broomstick between the brake pedal and the seat, so the pedal is pushed about 1". This gets the MC pistons past the comp ports so fluid can't drain from the reservoir, so you will lose very little fluid when you open the line.

AngryCorvair wrote: Wedge a broomstick between the brake pedal and the seat, so the pedal is pushed about 1". This gets the MC pistons past the comp ports so fluid can't drain from the reservoir, so you will lose very little fluid when you open the line.

Just this weekend I watched an old episode of Wheeler Dealers where Edd China gave this same tip. Good idea.

stuart in mn wrote:

AngryCorvair wrote: Wedge a broomstick between the brake pedal and the seat, so the pedal is pushed about 1". This gets the MC pistons past the comp ports so fluid can't drain from the reservoir, so you will lose very little fluid when you open the line.

Just this weekend I watched an old episode of Wheeler Dealers where Edd China gave this same tip. Good idea.

That is brilliant. Wish I knew that a week ago. I just did the main lines I the h2. The bad part was as soon as I got those done and I was testing the system the tear lines blew out. So I am now going to suck it up an replace all the hard lines in the truck.

There's no need to have the truck running while you bleed the brakes.

If you let it drool and keep the reservoir topped up, you'll actually have very little bleeding to do. Work from the master towards the calipers so it can fill the lines as you go. Keep the bleeder open on the caliper and it'll finish the job for you. They don't usually leak all that fast.

APEowner wrote: There's no need to have the truck running while you bleed the brakes.

It's a good idea to fire up the engine so you have vacuum assist and really romp on the pedal when you're done after doing a lot of brake work. Better to find any leaks under maximum pressure at this point than later. But you don't need the engine running before this test.

Good tips. See, that broomstick tip is the kind of thing I knew was here somewhere...