Brake Line Wrench

I need to go buy a line wrench to replace my wheel cylinder and rear brake assembly. Does anyone know what size line wrench I need to buy for the rear line going into the wheel cylinder?

3/8 line wrench get a good one the cheap one tend to flex some and can strip out the fitting.

You just might want to spray the connection with some penetrating oil.

Recently replaced all four lines, three no problem, fourth was a dirty blankety blank.

They can be stubborn at times.

joe_peters said:

You just might want to spray the connection with some penetrating oil.

Recently replaced all four lines, three no problem, fourth was a dirty blankety blank.

They can be stubborn at times.

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You say you replace all four lines, all the way to the Master Cylinder?

No. I mispoke. Replaced OEM flexible lines at front calipers with longer ones, and longer single line in rear due to 4.5" lift.

The problem was where the steel line connects to the flexible line in the wheelwell.

Hope I didn't cause to much confusion, but same applies to wheel cylinders.

XJ Stryker said:

3/8 line wrench get a good one the cheap one tend to flex some and can strip out the fitting.

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X 2 to the tenth on "get a good one." Both flex and slightly poor fit will frustrate you even on relatively nice looking ones, even at the Craftsman level. Go to a good auto parts store and get an S-K or a Snap-On 3/8 and 7/16 size. A single wrench may set you back 14 bucks or more, but you will never be sorry.

I always break the fitting loose with a pair of Vise grips first. Then soak the fitting in penatrating oil. Slowly work fitting back and forth to loosen rust between fitting and tube. Take your time sos not to twist off the tube. On severly rusty lines remove bolts from cylinder then turn cylinder holding fitting with Vise grips. A little time spent at the begining will save you from replacing the hard lines.

MAY POP said:

I always break the fitting loose with a pair of Vise grips first. Then soak the fitting in penatrating oil. Slowly work fitting back and forth to loosen rust between fitting and tube. Take your time sos not to twist off the tube. On severly rusty lines remove bolts from cylinder then turn cylinder holding fitting with Vise grips. A little time spent at the begining will save you from replacing the hard lines.

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That's what I used to do before I discovered really good flare nut wrenches. Now, if the nut has not already been damaged by vise grips, I use the correct wrench. The penetrating oil and the back and forth movement are the same, but the good wrench makes the line and fitting easier to reuse.

MAY POP said:

I always break the fitting loose with a pair of Vise grips first. Then soak the fitting in penatrating oil. Slowly work fitting back and forth to loosen rust between fitting and tube. Take your time sos not to twist off the tube. On severly rusty lines remove bolts from cylinder then turn cylinder holding fitting with Vise grips. A little time spent at the begining will save you from replacing the hard lines.

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Sorry to disagree, but you should NEVER, NEVER use pliers or vise grips on a nut, bolt, or fitting unless it is a measure of last resort because it is already totally F.U. If you have time, soak it down with breakaway or penetraing oil a day before. Use a line wrench (a good one) for the line fittings. For tough bleeders, a deepwell 6 point socket works best. Keep the vice grips in your tool box unless you plan to replace the lines too. The tricky part is getting the lines started back into the wheel cylinders. Always get the fitting to start 3 or 4 turms before you put a wrench to it. If you can't get it to start by hand, you need to bend the line a little to line it up better. Then start it by hand.

Before the nut strips, try a heat pistol. Not something I do on a regular basis, but sometimes nothing else works. Sometimes nothing at all works, though I've only really screwed it up a few times in 50 some years.
I've got four sets of line wrenches, but sometimes your best just isn't good enough. I try reasonable pressure with a line wrench first, you never know you may get lucky. I have a set of line wrenches that actually gets tighter as more pressure is applied, sometimes they won't even work.
Then the vice gripes, with the vice gripes jaw pressure is important. Too tight and you crush the nut, too loose and it slips and the nut rounds off. Wiggle it back and forth after using some penetrating oil. I have a set of vice gripes, that I lightly filed so the teeth aren't too sharp that I use.
Then the heat gun if necessary, periodically spraying it with oil and wiggling. This can be especially helpful when the line is stuck to the nut.

One of those things I've been doing for so long I often forget I'm even doing it.
I grease my vehicles often, I also brush, then rag off and re-grease all of my brake fittings. I have a can of synthetic grease and a small brush I use.
A coating of grease on every brake fitting once or twice a year actually works wonders over a ten year period. Especially in salt country.
Is it worth 15-20 minutes a year to avoid most brake fitting problems, for me it is. I'm a big fan of grease and grease my vehicles often and lubricate anything that moves.
Grease is your friend.

Antiseize works great on the bleeders too. I pull the bleeder, wire brush it, smear with antiseize, and then use gravity bleeding. The antiseize helps prevent pulling air past the threads.

Hallo. This is the best wrench, I could buy (Snap-On 3/8"x7/16").It cost more than a watch.(Matthew Currie 14 bucks?) It is a special one with 9 points!
The steel brake line is indeed mostly corroding inside the nut., so the line will turn together with the nut.
I use SuperLube Synthetic Grease to prevent that.
Yes Mud,Grease is our friend. LOL