Hard to Start Hydraulic Pipe Fittings.

[geodon]

Getting 3/8UNF unions to start threading has been the bane of my life for decades!

That's especially so when working in cramped conditions like the master cylinder on my Dauphine & lately the rear callipers on this (expletive deleted) XJ6 I'm working on for a mate.

But I think I've found a way to get them to start 1st time every time.

I use 2 open ended spanners, one small (eg 8mm) to fit over the pipe & one for the hexagon fitting usually 7/16AF or 11mm

1. Put the fitting in the hole
2. Make sure it's absolutely perpendicular to the hole
3. Push firmly on the fitting with the smaller spanner
4. Turn the hex with the bigger spanner

Worked brilliantly on the calliper cross pipes in very cramped conditions. I was close to removing the callipers to put the pipes on!

 

[COL]

I have found from experience to try and not bend any solid brake lines as it will make it difficult to get the threads started on assembly.

Also sometimes it is hard to turn the lock nut as small particals of dust get in between the pipe and the nut and there is sometimes not enough straight pipe to move the nut up the pipe and clean.

 

[DoubleChevron]

bubble flares are the same. I find I usually need to bend the line so its perfect. If you can't get the first few turns by finger ...... you are cross threaded. 90% screw straight in ...... 5% take forever to screw in (screaming abuse at it helps )

 

[Wildebeest]

It will be often found that the nuts on flare pipes will also flare slightly. Removing them, yes. But refitting becomes difficult.
It may be fixed by lightly [thread] filing the flare nut.