Harnd brake lines leak

[C1ph3r]

Hey guys. I am finally getting to my disk brake conversion. 1970 C10. Early Classic disk conversion.

I have only replaced hard lines once before and it was a disaster as well. Sold that project before it ever hit the road.

Now here I am again replacing hard lines and I have the same problem with the connections leaking.

It seems all of the connections leak. And that's without ever putting my foot on the pedal. What could I possibly be doing wrong?

I line up the line into the union until I can thread the fitting in by hand, then I tighten it down with a flare nut wrench. They are leaking at 2 of the 3 connection on the distribution block to the front brakes and at the fittings at one of the brake hoses. The ones at the prop valve look fine and at the master. But then again, I havent put them under any pressure so they may very well leak there too.

If the line isn't 100% straight in the fitting would that cause this? Seems that I have to bend and manipulate all the lines a little to get them to line up in the fitting loose enough to thread the fitting by hand. Then I am wondering when i take my hand away if they are getting into some sort of bind.

I am using a hard line kit i got from the Truck Shop. It is made by a company called Fine Lines.

This doesn't seem like rocket surgery. obviously for me it is, 2 vehicles i have attempted this with and both with the same result. Apparently I dont know what the hell I am doing. Cand rebuild suspension, pull motors, replace motors, and do all manor of automotive repair, but hard brake lines. Nope. Cant do it.

Maybe the pre-bent lines i always buy are junk.

[cg285]

nothing difficult about brake lines. who flared them?

[C1ph3r]

Originally Posted by cg285

nothing difficult about brake lines. who flared them?

I feel like it shouldn't be this hard. But I literally have a slight panic attack when working with them.

This was a pre-bent brake line kit. It was complete already.

[chevy_mike]

Here's the trick I use for any new lines. Get them started by hand, making sure to not cross thread the nut. Make sure you are using Flare Wrenches and not standard open end wrenches. Tighten the nut up snug and then give it a torque to about 20-25 ft. lbs. (you just have to feel for this). Then back the nut off about a half turn. Then re-tighten the nut back up as before.

What this does is get the flare reset onto the fitting. New lines seem to need this where old lines do not. I started doing this about 10 years ago and almost have zero leaks on new lines. For whatever reason I seem to be the guy who gets asked (and on my own projects) to do brake lines. Done well over two hundred fittings during that time.

[cg285]

put some more force on the wrench
Posted via Mobile Device

[C1ph3r]

Originally Posted by chevy_mike

Here's the trick I use for any new lines. Get them started by hand, making sure to not cross thread the nut. Make sure you are using Flare Wrenches and not standard open end wrenches. Tighten the nut up snug and then give it a torque to about 20-25 ft. lbs. (you just have to feel for this). Then back the nut off about a half turn. Then re-tighten the nut back up as before.

What this does is get the flare reset onto the fitting. New lines seem to need this where old lines do not. I started doing this about 10 years ago and almost have zero leaks on new lines. For whatever reason I seem to be the guy who gets asked (and on my own projects) to do brake lines. Done well over two hundred fittings during that time.

I'll give it another go. Already ordered some bulk line to make some myself. I have loosened the fittings and tightened them back down already. I'll give it another go. And put more force on the wrench.

[El Dorado Jim]

put a little lube on the threads, will help them tighten up

[PGSigns]

Here is what I do with new steel lines. I put a steel adapter with the correct size for the line in the vice and than screw the new line in it and tighten it up a couple of times. That seems to settle out the double flare in the new lines. The new nickle copper lines seem to seat well the first time with the new material.
Jimmy

[chevy_mike]

Originally Posted by C1ph3r

I'll give it another go. Already ordered some bulk line to make some myself. I have loosened the fittings and tightened them back down already. I'll give it another go. And put more force on the wrench.

Are you using a Flare Wrench or a regular open end wrench? Makes a difference as you can apply more torque with a flare wrench without the risk of rounding off the nut.