Bill Ball

I need some suggestions. I have a very stuck fuel return hose (goes from the fuel pressure regulator to the rigid fuel line cooler section on the firewall). This is 19mm hose nut with a 17mm counter-hold on the fitting. I've usually been able to break these free with a firm tug, often with no or almost no counter-hold. Not this one. I need to get it off to install an FMU for a Murph Stage 1 SC I am installing on a buddy's 90 S4.

I usually pinch the19mm and 17mm wrenches together, holding the counter-hold stationary. In this case, the wrenches move together but the fitting won't break free. I'm afraid I may snap the fitting off the rigid line and create a catastrophe.

I sprayed the fitting with penetrant and banged on it a little to try to break any corrosion. I'm reluctant to use heat, but maybe mild heat with a heat gun would be safe.

Haven't had this tough a nut before.

Ideas?

TIA

Mrmerlin

Hey Bill worst case is you cut the nut with a dremel of course this destroys the nut/fitting.
First i would soak the fitting with some Kroil or PB blaster if you have a heat gun use it keep a fire extinguisher handy and i do mean handy after a few heat than sprays let it sit for a few hours then do this again. We have had a few of these fittings that had to be cut off at the shop.
Then do the heat then counter hold with the wrenches. Also before you try to loosen the fitting try to tighten it then loosen it should come loose, Goodluck

Bill Ball

This looks like another one. I guess I'll get on the phone to Jim and order a new return line. I need to have it intact for the FMU fitting.

jorj7

I'd hit it with WD40 tonight and try it again tomorrow morning.

Richard S

OT...so who's gonna fill us in on the loooooong hot day Sunday?....

Rich

Charley B

What does move together mean, Bill? Are you saying you're getting movement of the wrench but not the fitting?

I've had luck in this situation by using a screw clamp over both wrenches.

You might also try a hammer on the moving wrench if you can brace the counter holding wrench well enough. Don't try if counter wrench isn't totally solid.

A pipe on the turning wrench would help but propbably no room in there for that.

Good luck.

heinrich

Bill the cooler is very soft. If AC isn't charged, pull it with the line attached and do it on the bench. Otherwise, I question why you need o pull that line? If you don't need to, just pull the other end off the damper/reg.

Bill Ball

The AC is currently not charged, so, I might remove that if I have the right o-rings for it. Good suggestion, although it still might require cutting. I have to pull the fuel return because the SC FMU attaches to that end of the line. With the hoses provided with the FMU I don't think I can rig it any other way, but I will look at it again.

Bill Ball

I can squeeze the wrenches together but the nut does not move. I believe I am counterholding the cooler fitting, but as Heinrich said, this thing is soft. There's no room for a hammer. I did use a pipe over the wrenches for more leverage, but it doesn't feel good when I honk on the wrench. I've gotten pretty good at feeling when things are not giving as they should. Right before I snapped off Nicole's brake bleeder, I said, "This does not feel right."

Charley B

If you can wedge something between the counter hold wrench and the firewall you can then honk on the breaker wrench with confidence. The softness of the cooler shouldn't be a factor, as long as the counter wrench is imobilized against something. The breaker wrench should be the tube fitting type.

Leon Speed

Bill, is the wrench slipping or does it feels like the fitting is twisting? In the first case you might want to try extra grip wrenches like Craftsman Extreme Grip. Second case..dang.

jon928se

Bill - try my trick of using a spring compressor (or make something similar - use some threaded bar,nuts and some "hooks") between the rings on the other ends of the spanners. This will allow you to apply a lot more very carefully controlled force to the ends of the spanners and can't put any torque at all onto the fuel cooler threads. It will also enable you to seat the open ended spanners onto the union nuts and use a spare hand to keep them there.

Bill Ball

There's not much room for hardware in there. I tried honking on it some more. It looks terminally stuck. Dremel cutting wheel in the am.

Tails

Bill,

I can say "I been there, done that and got the "T" shirt".

The problem is that the fuel removes all the lubrication between the union and the nut and you have firm metal to metal contact and it is very difficult to get any penetrating fluid between the metal to metal contact to reduce the friction sufficiently to undo the nut.

The best method for fuel pipes it to give one spanner a firm crack, whilst the counter holding spanner is wedged up against a firm surface.

In many instances I have use a metal object held against the counter hold spanner and given the spanner a firm crack relying on the moment of inertia of the metal object to prevent turning, however, in this instance there is not much room.

One thing I have noticed with you is that you never say "die", so undoubtly you will come up with an inventative method to "crack" the union.

Look forward to hearing how you go.

Tails 1990 928S4 Auto

mj1pate

...with asbestos parka. Tread carefully.