How to loosen 'frozen' steel brake line fittings?

KFC911 · 01-17-2003, 11:58 AM

I'm in the process of replacing my original rubber brake lines, and have encountered a couple of fittings (on the steel lines connected to the rear calipers) which are not breaking free (even though they don't appear corroded, etc). I've searched the archives, and although everyone cautions against damaging the steel lines in this situation, I haven't seen any tips on actually loosening the fittings. I ran across this last night, so I sprayed them with Rost-Off, and will try again this evening. Does anyone have a suggestion if this fails? Should I attemp to counterhold the steel line w/ vise grips (without crimping the line), use a torch to break them loose, or what? I sure don't want to damage these lines, so any tips are much appreciated!

atlporsche · 12:44 PM

the threaded part is probably rusted to the hardlline...trust me...

if you're lucky, you'll break them free, if unlucky, you'll stress the hard line...

They're really not all that expensive if you have to bend another one.

you won't hurt the hardline with a torch...I torched a couple of bleeders out once...

sjd

Targa Dude · Targa Dude's Garage

Use a Flare nut wrench..

Jorge (Targa Dude)

KFC911 · 01-17-2003, 12:40 PM

Alas, I am indeed using a flare wrench, but it seems that atlporsche has been there before and knows what I'm talking about....I'll just give it another shot and hope for the best...

atlporsche · 01-17-2003, 12:44 PM

I had very rusty calipers in a '67.

I ended up replacing all the hard line.

sjd

KTL · 01:53 PM

Torch may be helpful in softening up the cosmoline and other crud on the line.

The trick is to give the line a quick turn of the wrench. Slowly turning it can start the line twisting. A sharp movement may break the crud free.

I agree the flare wrench is the proper tool, but sometimes you can't place the wrench in a location such that you can get a good turn on the fitting the way you'd like. Don't be too hesitant to use a standard open-end wrench.

The steel lines are indeed not that expensive, but I do recall one of the rear steel lines (goes from the splitter at the firewall to the rubber flex line) was on backorder for a while.

I also remember someone saying tobasco sauce works at freeing up rusted/frozen brake lines. Go figure! Never tried it myself BTW.

Edited to better describe why I sometimes don't use the flare nut wrench

Superman · 01-17-2003, 01:22 PM

Penetrating spray and patience. Remove the caliper and attached line if necessary to get a good angle. I'd suggest staying with the flare nut wrench whether or not you plan to replace the hard line. Get a good angle and make it an offer it can't refuse.

atlporsche · 01-17-2003, 01:24 PM

tobasco sauce??? I guess all the acid in there...

or coke...it'll actually eat the line. It's amazing we drink the stuff.

sjd

old_skul · 01-17-2003, 01:27 PM

Your body has acids in it which neutralize the alkaloids in Coke. (And many other foods, for that matter.)

Uh, anyway, what Superman said. And don't sweat it - if you have to replace the hard lines, they're not at all expensive ($4 a length at Pep Boys) and they're easy to bend if you have a tube bender. I second the motion on penetrating spray (I used WD40) and removing the caliper to get the better angle.

69911e · 01-17-2003, 01:51 PM

PB BLASTER is the way to go first; just let it sit 30 min. I never had much luck with wd40 or any other oil product. I tried PB Blaster and was amazed!!! Plus it has a much higher vapor point than WD40, good for the torch.
But it is no big deal to just make new line yourself either....

dtw · 01-17-2003, 02:02 PM

Set up flare nut wrenches on flex and hard lines such that if you squeeze them toward each other with one hand, you have another hand free to whack at the flex line wrench with a hard rubber mallet. If you are keeping tension on the two wrenches with one hand, the mallet should break the bond in short order. Be careful not to pinch the ***** out of your hand when the two wrenches come together. Ask me how I know.

As a last resort- yes, the hard lines are cheap to replace.

Good luck.

Jim Sims · 01-17-2003, 02:37 PM

If the flats on the nut become hopelessly rounded (warranting replacement of the hard line anyway) use a small pair of "visegrips" to grip the rounded nut. Kroil, PB blaster or a good penetrating oil are useful to soak the fittings with. WD40 is useless in my opinion. One can also use a Dremel tool to split the nut by cutting if all else fails. Good luck. Pelcan has the OEM hardlines and they are not expensive. Jim

KFC911 · 01-17-2003, 04:02 PM

Thanks to everyone for their reply! In my case (she's somewhat of a garage queen), I've cleaned every bit of cosmoline, crud, etc. off, and it's spotless. I did use flare wrenches on both the steel line fitting, and the rubber hose side, and those broke free fairly easily. My problem is that when the fitting on the steel line turns (I haven't turned it much at all, and was using a very light touch), the steel line is frozen to it, and the line is turning also. I'll give it another try, and it'll either break free or break...I didn't realize that replacing those lines wasn't too big of a deal.

Tom F2 · 01-17-2003, 06:42 PM

The brake line is copper, or some copper alloy. The copper swells inside the fitting to the point where you can't break them free, even on the bench. You just can't save these things. Buy new ones from Porsche. They're not expensive. The old fashioned steel lines didn't have this problem as much, but then again, they would rust out and cause brake failures!

I'm not sure about using a lot of heat on brake lines. I remember some nasty pops last time I did it, but that was a long time ago.

Jim Sims · 01-17-2003, 08:34 PM

OEM hard brake lines are a coated steel. Copper and copper alloys are not used due to their poor fatigue life in vibrating vehicle environments. IMO stuck brake line fittings are usually due to rust or from being overtightened. Cheers, Jim

slammed1000 · 01-17-2003, 09:56 PM

do not use a torch! brake fluid is very flamable. you will cry when your whole brake system catches fire and burns your car to the ground. we scrap a lot of cars and i am more afraid of brake fluid than gasoline! use a flare wrench and some pb blaster or something equivelent. buy new lines if need be because they are cheap compared to the headaches you are going to spend getting them apart.

john70t · 01-18-2003, 12:44 AM

A not-so fun high school experience was carefully watching a friend torch a bleeder screw and having the rubber line blow up like a baloon and pop in our faces.

Tom F2 · 01-18-2003, 04:00 AM

Re. brake lines steel or copper - try a magnet on Volvo or Porsche lines - they're not steel.

Jim Sims · 01-18-2003, 04:15 PM

Just checked the OEM hard brake lines on a '73 and '76 911 and they're just as I remembered: carbon steel, magnetic and prone to rust when the coating/plating is gone. The flexible bits are of course reinforced rubber hose. Metal non-magnetic brake lines could be aluminum or even some grades of stainless steel. Both of these metals will present some serious galvanic corrosion problems of their own when combined with steel or iron components. These problems can be solved with some additional complication. Recall the common aluminum external oil housing to steel nut son the oil lines corrosion problems. Cheers, Jim

Tom F2 · 01-18-2003, 06:35 PM

Yes, this is right for the early cars. The changeover to copper came around 1980, same as for Volvo. My '79 has steel lines, my '83 has copper lines. I don't think that the copper is anything like a soft alloy as in household piping. It's much harder. And, it's definitely not magnetic.

A propos of nothing in particular, I note that Volvo and Porsche seem to share a lot of technical details. Anyone know whether Porsche does development work for Volvo, as they do for Harley Davidson? My other car is a Volvo turbo.