Tool Question

If they are not too tight, too rusted, too frozen, yes an openend will sometimes work. But the proper wrench increases the chances you will get it done without destroying the fitting.

I found out the first time I tried to change out a brake line. Thought it was my cheap wrench so went down to Snap-On (they actually had a _store_ in that town) and got one of theirs and it spread and slipped too. I took it back and complained and the guy behind the counter asked me what I was trying to do and I told him and he said "Oh, for that you need a flare-nut wrench" which I bought and lived happily ever after, at least after I filed the burrs off the fitting that I had put there with the open end wrench.

Sometimes an open end wrench will work on a flare nut, sometimes it won't--depends on how tight it is.

Now, the problem with using an open end wrench is that if it _doesn't_ work you've buggered up the fitting and will probably need to do some dressing on it to get the flare-nut wrench on it and if it's buggered up badly enough you may not be able to get it off at all with _any_ tool without cutting the brake line.

You're going to want to clean the fitting as best you can by the way--a good flare-nut wrench is a tight fit and crud on the fitting may prevent the correct size from going on at all.

BTW, in an emergency a flare nut wrench can be made from a (good quality) box wrench and a die-cutter... Remove just enough to allow it to slip over the brake line, and no more.

The flare wrench contacts the corners of the flare nut, the regular wrench contacts the flats. Due to the nature of the flare fitting, working on two flats can cause the fitting to be deformed.

Followed by a pair of big honking vicegrips, a new nut, and a flaring tool. I keep a 6-point box end for the bleeder valves and I've twisted off more than I like to remember - those suckers seem to grow in there. Some people suggest using a small hammer to tap all around the nut to help break them loose but that never did much for me. A quality wrench is the answer.Once you get it started anything will do but that first pop is critical.

I keep a 4 inch pipe wrench handy when I bugger up fittings

I keep a 4 inch pipe wrench handy when I bugger up fittings

What do you use it for, a club?

OOPs, a 4-inch club is not very persuasive. What was I thinking?

Exactly! A great little tool.

So do I use a six-point wrench or an eight-point wrench? I thought the wrench should contact the flat spots. Otherwise you tear off the corners of the nut, making it a round nut.

Bwa-ha-ha... I was thinking the same thing: a club against bugs perhaps?

If you have to get a wrench, get a Flare Nut wrench and be done.

The bleed fittings can be opened with any box-end wrench, and you might even have room to use a 1/4-drive socket. The box-end wrench works best/easiest, but a socket can be used if there is space available.

The flare fitting and the bleed screws are 6-point. The bleed screw can be opened and closed with a 12-point, but this is not a good idea.

So what size wrench do I need to buy (or wrenches plural)? Thanks

Should be a 3/8.

Note that a 3/8 flare nut wrench is 18 bucks from Sears but they have a four piece set for 15 and a a five piece set for 20, if you can find one--you may have to order online. While you're out get a small wire brush (the kind you use for cleaning barbecue grills and the like) and an emery stick (if you can't find one at a hardware story try in a drug store with the nail files) to clean any crud off the fitting if the wrench won't go on at first--the emery stick will get behind it which is hard to do with the wire brush.

Thanks J. So all four flare nuts going into the proportioning valve are