Flexi brake hose - corroded to fixed pipe

Dr_Colossus

Great plan this morning to replace the front flexible brake hoses on a 07 Volvo S60 that recently failed the NCT for weathered hoses. Should be a simple job but the cursed flare nut is corroded to the fixed pipe on both sides and I'm not willing to give it more than a half turn in fear of twisting the pipe and damaging it. Any ideas or will it mean having to replace the brake lines entirely which is a much bigger job and one I'll have to bring to a garage. Any idea of a price for that?

The brake lines are steel looking and coated in a protective plastic like substance which I stripped back a little around the flare nut. Such a poor design, can't understand why there isn't a lock nut type fixing on the flexible hose end since this is what's normally replaced and expendable.

biko

Did you spray liberally with anti-seize spray?

If you did then using a wrench on pipe and wrench on nut and wiggling should set it free eventually, with a lot of cursing.

Dr_Colossus

biko wrote: »

Did you spray liberally with anti-seize spray?

If you did then using a wrench on pipe and wrench on nut and wiggling should set it free eventually, with a lot if cursing.

Yea doused it yesterday in spray to let it soak in over night as my primary fear was the flare nut seizing with the flexy hose connection and potentially stripping the flare nut. The connection was handy but not with the pipe itself and fear was taking hold as didn't know how much twisting the pipe could take. Didn't try clamping the pipe itself but guessing it wouldn't take much to compress/damage it so not sure how much grip I can get on it.

Would a garage normally use heat to try and break the connection or if looking like a pain just go straight to replacing the brake lines and charging accordingly?

rex-x

If its rusted badly enough to be stuck then even if you do get it free the brake line will be compromised anyway so will need replacement. Just jump to replacing it, you can add a joiner and flare it maybe 1-2 feet down the line where there is no corrosion, not necessary to replace the entire thing.

Buffman

Dr_Colossus wrote: »

The connection was handy but not with the pipe itself and fear was taking hold as didn't know how much twisting the pipe could take. Didn't try clamping the pipe itself but guessing it wouldn't take much to compress/damage it so not sure how much grip I can get on it.

You'll have to use a bit of force on it. The pipes are actually robust enough as long as you don't go too hard on them. Hold it in place with a cloth covered pliers to stop it rotating with the nut. To do any damage you'd have to squeeze it hard with a vice grips.

Dr_Colossus wrote: »

Would a garage normally use heat to try and break the connection or if looking like a pain just go straight to replacing the brake lines and charging accordingly?

Ye, heat would be the next step, but anything hotter than a heat gun would be asking for trouble IMO. Replacing the whole pipe run would be a bit overkill.

Dr_Colossus

rex-x wrote: »

If its rusted badly enough to be stuck then even if you do get it free the brake line will be compromised anyway so will need replacement. Just jump to replacing it, you can add a joiner and flare it maybe 1-2 feet down the line where there is no corrosion, not necessary to replace the entire thing.

That's the thing, there's no visible corrosion at all, the line itself is coated in a plastic like covered right into the nut so well sealed. Thought brake pipes were only in copper or steel but I have my suspicions this might be aluminum as feels quite soft and was turning easily with the nut hence my fear of sheering it off. Aluminum could also explain the binding with the flare nut which I'm guessing is brass.

rex-x

Dr_Colossus wrote: »

That's the thing, there's no visible corrosion at all, the line itself is coated in a plastic like covered right into the nut so well sealed. Thought brake pipes were only in copper or steel but I have my suspicions this might be aluminum as feels quite soft and was turning easily with the nut hence my fear of sheering it off. Aluminum could also explain the binding with the flare nut which I'm guessing is brass.

Its steel and the rust is inside the nut, not visible until its removed. They always split there as the plastic coating must be removed to flare the pipe, its incredibly thin walled so even slight pitting is dangerous. I have seen many burst exactly where you describe.

Buffman

Dr_Colossus wrote: »

That's the thing, there's no visible corrosion at all, the line itself is coated in a plastic like covered right into the nut so well sealed. Thought brake pipes were only in copper or steel but I have my suspicions this might be aluminum as feels quite soft and was turning easily with the nut hence my fear of sheering it off. Aluminum could also explain the binding with the flare nut which I'm guessing is brass.

It's probably a copper-nickel alloy (cupronickel/cunifer). It does have a protective film around it. Probably looks dark green like this.

martyc5674

What I've done in this scenario (more than once) is the following.
Disconnect caliper from car(leaving hose on...we'll get to that)

Put spanner on nut(nut on brake pipe)
Other spanner on brake hose..rotate brake HOSE whilst holding the "nut on brake pipe" stationary. (The whole caliper will spin as you do this,hence removing it first)

Fit new hose in reverse...again twisting hose onto nut and not the other way around...then rotate caliper onto hose...refit caliper bleed the brakes and your good.
Alternatively it's not that hard make up a shot but of brake pipe with a joiner.
Marty.