What am I doing wrong?- brake line

[70c10]

I have installed 2 different brake lines in the last week on the passenger side of the rear axle and both have leaked at the junction block where they split to each rear wheel This should be a 5 minute job but I can't get the short line to stop leaking at the junction block! I looked in there and all the threads look good. How can I fix this?

[Palf70Step]

What does the flaring seat and flare look like. I had one that had a small nick in the T-block fitting and would leak no matter what I did to it until I replaced it.

[tcb-1]

I know that some people use a petroleum resistant teflon tape, but make sure you get none on the tube mating surfaces.....

now for me, I had the same issue when I plumbed up 15 or so new lines. my MAJOR problem was that I was not torqueing the nuts down enough. I forgot the in/ft lb of torque they take, but after I went back through and tightened them down, I have'nt had another leak. remember, your trying to get metal to seal against metal, so the torque to do so will be more than you may think!

and double check your 45 degree double flares and make sure they are true and absolutely clean.

[Classic Heartbeat]

The brake line itself is not seating to the junction block. You may have a bad line or block. Also if you have stainless steel lines they are harder to get to seat than the steel ones. The fittings are not self seating pipe threads, so the threads can look just fine and the line will still leak. WES

[70c10]

Originally Posted by Classic Heartbeat

The brake line itself is not seating to the junction block. You may have a bad line or block. Also if you have stainless steel lines they are harder to get to seat than the steel ones. The fittings are not self seating pipe threads, so the threads can look just fine and the line will still leak. WES

WES, this is steel line. I don't think the block is bad. It's never leaked.

[70c10]

The first line I thought maybe I tightened it too much and crushed the flare but when I took it off tonight it looked good. I figured just to be safe I installed another new line and this one leaks also. I've never had to use teflon on brake line threads. I'm going to try removing it one more time to take another look but this is getting frustrating now. Thanks for the input so far!

[68 short step]

replace the t-block....sounds like there is a burr in there (like 70step said)

[70c10]

Where can I get a new block?

[68 short step]

the threads isnt the sealing part, its the flare.....and id say its either the lines or the block, but with 2 diffrent lines odds are its the block......

[Billla]

Originally Posted by 68 short step

the threads isnt the sealing part, its the flare.

- it's easy to have the flare not seat and then tighten the line. Make SURE the flare is seated against the fitting.

[70c10]

Thanks for encouragement guys!. I had the truck out last Friday for the first time in 6 months and put about 50 miles on it Like always, it ran like a champ! I'm just anxious to start the cruising season. I'm in a much better frame of mind today than I was last night

Bill- that's what I'm thinking but isn't the flare (by design) supposed to seat itself as the threads are drawn up?. Even if it was not flush, as you begin to tighten it straightens itself out I thought. I know this is a simple fix, I'm not stressing anymore. I'll just take it off and have another look at the threads I'm trying to get the brakes ironed out before the new heads go on next month

[Billla]

Originally Posted by 70c10

that's what I'm thinking but isn't the flare (by design) supposed to seat itself as the threads are drawn up?

Design: The reason engineers give when something doesn't work

Seriously, yes, it should - but it sometimes doesn't. I always seat the flare and hold light pressure against it, then tighten down the tube nut.

[70c10]

Originally Posted by Billla

Design: The reason engineers give when something doesn't work

Seriously, yes, it should - but it sometimes doesn't. I always seat the flare and hold light pressure against it, then tighten down the tube nut.

I'll make sure to seat the flare first and then tighten. Thanks again!

[Old Money]

do you have long threads on the end that leaks .i found you dont get enuff torque. the brass fitting is a little too long . if thats not it i woud still replace the fitting and start over. i am from wi. and we always do it twice. murphys law. if it jams force it, if it breaks its defective. Old Money.

[68 short step]

Originally Posted by Old Money

. i am from wi. and we always do it twice. murphys law. if it jams force it, if it breaks its defective. Old Money.

[Classic Heartbeat]

We have them in stock. They are $19.95 plus shipping. They are not readily availible at your local hardware store. They have two different sized threads. WES

[Classic Heartbeat]

The local parts stores will tell you that they have been discontinued also. I searched for a long time to locate these. WES

[70c10]

Originally Posted by Classic Heartbeat

They have two different sized threads. WES

WES- the lines that I bought going to each wheel cylinder are 3/16". The fittings on these lines take a 3/8" wrench.

[Classic Heartbeat]

If you take the lines loose, you will see that the rubber line that goes into the block is larger than the two that go to the wheel cylinders. WES

[68 short step]

i would think a 1/8" NPT female, flared, T-block could be bought at ACE, LOWES, HOME DEPOT, ETC...

[70c10]

Does anybody know where to get a new junction block???

[70c10]

Thanks for the info WES- I'm going to check the line again but I may be calling you to order one soon.

[Classic Heartbeat]

Sounds good, I have 4 or 5 in stock. WES

[70GMCer]

Jim, you might want to leave that hose and block alone right now. If you try a loosen a 40 year old hose, you might be opening another can of worms. Relax.....we'll get it......I'm free on Saturday....

[70c10]

Thanks Steve! I should have had this fixed in 5 minutes but you know how that goes!