Help! Brake Union Stuck!

thescouselander

So what started as a simple bearing replacement on the other half's car has turned into a bigger job involving replacement of the rear brake shoes and a leaking cylinder:(

The problem is the union nut in going into the brake cylinder is stuck fast. I've tried everything from spanners to mole grips and of course lots of WD40 but nothing is working.


Ideas anyone?

colino

Does it have a horse shoe clip or similar keeping the cylinder in place? If so, take it off, take the bleed nipple off and try holding the brake pipe nut with a spanner and turn the cylinder off of the pipe. Usually works if you have the room. (Presume you've already soaked the joint with Plus Gas/WD40)

gilbert_and_sullivan

Try undoing the affected pipe/flexible at the other end, if it undo's OK there maybe you could get the slave cyl out complete with pipe attached...then if it won't come undone get a new pipe made up by the factors...course sods law decrees the other end of this pipe is routed over half the suspension and buried deep in the chassis..;)

thescouselander

Thanks everyone - a bit more wrestling with the mole grips did it in the end - the union nut isn't looking to pretty though.

Spitakimus14

replace the pipe and union cant be too safe with brakes.
Local car spares place can probably make the pipe

pwllbwdr

.... and in future, use a penetrating oil like plusgas, not WD40 - it is not a particularly good penetrant.

Keith

And brake pipe spanners

Inactive

pwllbwdr wrote: »

.... and in future, use a penetrating oil like plusgas, not WD40 - it is not a particularly good penetrant.

Spot on, WD40 is useless as a penetrating oil.

Plusgas or similar, left long enough to actually penetrate usually does the job.

thescouselander

pwllbwdr wrote: »

.... and in future, use a penetrating oil like plusgas, not WD40 - it is not a particularly good penetrant.

Yes, sound advice I'm sure. Unfortunately I did not expect to be replacing the cylinder today so I had to work with what I had as the local motorfactors (the only one open on a sunday) didn't have anything more suitable.

Stigy

Keith wrote: »

And brake pipe spanners

Absolutely!

The whole idea of a brake pipe spanner is that it's 'nearly' a ring type spanner, just that there's enough of a gap to get through a brake pipe. Much better than a standard spanner.

thescouselander

Stigy wrote: »

Absolutely!

The whole idea of a brake pipe spanner is that it's 'nearly' a ring type spanner, just that there's enough of a gap to get through a brake pipe. Much better than a standard spanner.

I did try a brake union spanner but it was just starting to round the nut off - it was really stuck.