HELP with rear drum brake adjuster

[metalmoto]

First off. Everyone on this forum and other Jeep forums, said they were SAE, domestic, or what I call American. 3/8 24 NF. (Except for connections to the master cylinder) which use metric with a bubble flare. I bought both the SAE and Metric lines, see which one fits, and return the other. I tried the SAE on the wheel new wheel cylinder, it screwed in and fit fine.
So I went with the line with the SAE fittings. After I had it all back together, including both wheel cylinders, and the flex line block on the axle. I pumped up the brakes, to make sure I had no leaks. And the only place it was leaking, was at the block on the axle. I tightened that some more, still leaked. When I looked up the parts specs, it says, M10 X 1.0 which is metric thread. Then I read on another Jeep forum, that you should use metric fittings. But it also said, SAE fittings will work also. Except in cases where the fitting screws in further. Like it will work on the wheel cylinders, short thread, but perhaps not in other places. Now it seems like the metric fitting will not even thread in to the left wheel cylinder! So I've been trying to flare one end of the line with a metric fitting. But the cheap flare tool I bought, broke after one use. Made a horrible distorted flare. Couldn't find an SAE to metric adapter at the auto parts store. So I rented their flare tool, to give that another try. Seems the problem is at the block on the axle, and the longer thread length, just wont seal with the SAE fitting!

 

[ltd02]

Okay, so you're saying the block is metric and the wheel cylinder is SAE? Is this a new block too or did you just replace the flex line to it? Could there be some crud in the block where you are trying to install the new hardline? Did you replace both hardlines? Sounds like only the left was replaced. Can you line up the two fitting ends (old and new) and see if their threads "superimpose" or match pitch? I think an m10 is close to a 7/16, so about 1/16 bigger than the 3/8. So if the thread pitch is the same then I guess that's why the 3/8 would thread in "loose" but the m10 wouldn't even go in a 3/8. It still seems like if the flare and its contact surface were true and clean it should seal. It can be real tough to do those complex flares with a simple flaring tool. Good thing you don't need a bubble flare. That would be impossible without the proper tool. Not sure what you borrowed/rented but even the inverted flare is very tricky without the right tool.