Loosening brake line fittings

Looking for some good-old mechanics wisdom here.

I tried cracking the fittings loose on the master cylinder, using a line wrench, and the fitting started to round off. I've had this happen to me many times when trying to change brake hoses and I expect it may happen here as well.

I've apparently got the right tools, maybe just not the right technique here. What should I be doing? Tips or tricks welcome!

vice grips work everytime,.

Use the correct size line wrench/use a quality wrench that fits tight. Were you using imperial or metric?

Generally, if they are well rusted I don't even bother trying to save them. Cut the line at the fitting and use a 6 point socket. If that fails, use a nut extractor. Replace with new fittings. A thin smear of anti-sieze around the end of the tube and on the fitting threads will help next time, but take care not to get any on the mating surface or inside the tube.

If you are desperate to save the fittings, sometimes you can clean off all loose rust, hit it with an acetylene torch (obviously not if there are combustibles in the area of the flame or if there is a rubber hose attached) then nail it with a good penetrating oil (avoid breathing the fumes, of which there will be plenty). The thermal shock will help and the residual heat will help wick the penetrating oil into the joint. Paraffin wax is an alternative, and wicks into a hot joint too. Once the fitting is removed, it can be gently clamped in a bench vise while the remaining bit of line is drilled out.

Master cylinder nuts don't usually get rusty..

jayoldschool wrote:

Master cylinder nuts don't usually get rusty..

Especially in seattle.

I had to deal with a set of corroded nuts on a FW. I use what is call a butterfly socket. They used to be available on ebay, but are expensive. I got a small size set, and they work on almost all of the fittings on the B-bodies and D-bodies. The socket is hinged, and when placed around the nut, and a ratchet inserted, the nut is effectively in a full circle socket, and unlikely to get damaged. I checked and the only ones currently on ebay are for large nuts.

Thanks guys, I managed to get the fittings loose- jayoldschool was on the money with the wrench size: the fitting is 14mm, not 9/16. That gave me a better grip, but it still wasn't budging. I sprayed some pb blaster in there just for good measure, even though there's no rust to be found. I used a piece of pipe on the wrench (more for comfort than torque, but it certainly helped) - tightened them a bit first, and then worked backwards slowly. Took a ton of force, but they eventually broke free. No idea why they were so tight because they're steel fittings going into the aluminum master cylinder body. Maybe they got welded together due to galvanic action or something.

Nick - I thought you were kidding about the vice grips. I tried the proper wrenches on the caliper hose, and the damn thing just rounded off. So I used two sets of vice grips, one on each side of the fitting and figured what the hell. Pulled on them really hard and well, it broke free.

It's buggered up pretty nicely now, but I can get it off without cutting or sawing. I suppose I should cut it off and replace it regardless if I can't get a wrench on it anymore.

Thanks!!!!

-Mike

Oh, Fred, I was thinking about something like that socket. I'm looking around too but so far only find big sizes. If I can find a 13mm one, it may make getting the other caliper hose off more easily.

Fred Kiehl wrote:

I checked and the only ones currently on ebay are for large nuts.

Checking the manufacturer's (EZ-Red) website, butterfly sockets are no longer listed in their catalogue. I'm guessing they are discontinued and the only NOS left are the big ones. Too bad, they look useful.

I'll do some asking around, if I come across some I'll let you guys know. They're pricey but even if it saves one trip to the shop, I think it'll be worth it.