Brass Union Seized Onto Copper Pipe

[Grim.Badger 15]

I'm trying to put my brakes back together and the brass union on the end of one of the copper pipes has managed to seize onto the pipe. I didn't notice this when dismantling as I'd had to cut the flexi hose anyway so must have been rotating that to get the hoses apart.

 

Now my caliper is all back together and I really don't want to take it apart just so that I can screw the flexi hose onto the copper hose, so can anyone tell me if it's possible to free the union bolt thingy from the copper hose so that I can screw it onto the flexi hose?

[welshpug 1,655]

quite unlikely in m experience, they tend to either crack free nicely, or just twist and kink the hard lines.

 

best course of action is to just replace that short section of line from the trailing arm to the caliper (do away with the silly short bit of hose) I stick plenty of grease on the threads and around the hard line where the union sits.

 

They're not brass BTW, yellow Zinc coated steel.

[stu8v 68 1 Cars]

Use heat, a gas powered blow torch should be fine to get it moving with no damage.

[Grim.Badger 15]

quite unlikely in m experience, they tend to either crack free nicely, or just twist and kink the hard lines.

 

best course of action is to just replace that short section of line from the trailing arm to the caliper (do away with the silly short bit of hose) I stick plenty of grease on the threads and around the hard line where the union sits.

 

They're not brass BTW, yellow Zinc coated steel.

 

Even if it is safe to use solid lines all the way to the caliper, I doubt many MOT testers would like to see it; also you aren't meant to grease brake pipe unions.

 

I ended up taking the caliper apart again and screwing the flexi-hose onto the solid hose and then screwing the caliper onto the flexi and refitting.

[welshpug 1,655]

Its how Peugeot Citroen did it from about 1997 onwards, so I don't see an issue with it, nor do I see the issue with stopping the union seizing with some grease.