Securing brake lines to the brake line blocks

[Dave K.]

When securing the lines to the line block is one suppose to use some sort of thread seal? Also is it easier to but the block onto the frame first and secure the line to it or secure the line to the block and then put the block onto the frame? I'm doing a frame off and putting chassis back together; so trying to figure out which is best.

[Gary C.]

Re: Securing brake lines to the brake line blocks

Dave,

Used what the aircraft guys call "fuel lube" on all brake and fuel line connections. Works great. Can be bought from any local aircraft supply house.

http://www.aircraftspruce.com/catalog/cspages/ezturnlube.php

Gary
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[Joe L.]

Re: Securing brake lines to the brake line blocks

When securing the lines to the line block is one suppose to use some sort of thread seal? Also is it easier to but the block onto the frame first and secure the line to it or secure the line to the block and then put the block onto the frame? I'm doing a frame off and putting chassis back together; so trying to figure out which is best.

Dave------


With all brake and most fuel lines, there is no seal accomplished at the threads. The TUBING NUTS simply serve to compress the line flare against the "cone-like" mating surface in the fitting. So, applying any sort of sealer to the threads will accomplish absolutely nothing as far as a seal is concerned. For brake lines, the pressure is so high that if an effective seal is not achieved at the flare, any sealant on the threads won't do a thing. For fuel lines, with much lower pressure involved, a gasoline resistant sealer on the threads might prevent a leak for short while but not permanently. However, it's still a mistake to use sealer since it might "mask" a seal problem when the installation is performed but then the leak appears subsequently "on-the-road". You want to get it right from the get-go.

[Mike E.]

Re: Securing brake lines to the brake line blocks

I would recommend using tube nut wrenches or flare wrench when tightening the tubes. With an ordinary opened end wrench you might not get the tube nut as snug without the wrench slipping. A useable set will cost $15-20. As with any tool you get pay for.

http://www.autozone.com/autozone/acc...er=247825_0_0_

Mike

[Richard M.]

Re: Securing brake lines to the brake line blocks

Dave, I always mount the blocks to the frame.

When tightening the lines to the blocks, use a open end wrench in the opposite force direction to hold the block rigid. Sometimes you can only get on a partial surface of the block to hold it steady.

Rich

[Phil D.]

Re: Securing brake lines to the brake line blocks

Recently did this, screwed it up and had to buy one new brake line so let me tell you how it did the second time. I attached the blocks to the frame, then the lines to the blocks and lastly clamped the lines to the frame while tweaking the bends to get them all parallel (or as close as I could). I messed one up by clamping the lines to frame first and trying to tweak the bends at the end to get it to screw into the block. I accidentally crimped the first line by trying to straighten and rebend it in a different spot to get it aligned enough to screw in. Figuring that it has to end at a very fixed point and everything in between is somewhat subjective is the proper thought process. I found the lines were pretty close but not perfect. Looking back at pictures of the rusty originals, they weren't anywhere near perfect either so I had to resist the urge to obsess.