ST165 fuel line coupler problem

[___Scott___]

I need to replace my fuel pump. Things were going well until I tried to disconnect the coupler in the fuel line near the tank. I can get wrenches on it but don't have enough leverage to break it loose. Any tips on how to get this apart would be appreciated.

Thanks.

 

[___Scott___]

Not exactly an emergency but I'd like to get this back on the road sooner rather than later.

 

[Dracov]

Unfortunately I have no good advice on this, despite replacing my own pump last year and running into the same problem. The hard line going to the tank is fixed, so it's the soft hose side that spins. I would suggest heaping doses of your preferred penetrating oil of choice (Kroil, CRC Freeze-Off, acetone+ATF, etc) and time to soak before giving it another go. Maybe a long reach wrench if you can fit one up in there.

You could also try to slightly lower the tank to get better reach, but then you have a loose tank hovering around on top of all the other pre-existing challenges

 

[simple]

I've fought that one before. Don't use a torch as you will melt the line between the tank and that fitting. The lines are no longer available OEM parts. Vice grips will just smash the flare nut.

Penetrating oil and patience. This type of connector has barely any torque applied.

 

[___Scott___]

I was in "Penetrating oil and patience" mode when I made the post. I'm going to try tapping it with opposing hammers if I can get them in there.

Thanks for the warning on heat and vice grips.

 

[grip-addict]

Do you have five-sided line/flare wrenches? Harbor freight has them for a reasonable price. Get a pair on there and then use a squeezing action with your hand to loosen. And... Yeah this job sucks. Take your time, don't rush it, Don't get frustrated, And all will be well.

 

[___Scott___]

I don't have flare nut wrenches but I'm at the point where that's the next thing to try.

I was able to get hammers up in there and do some pretty firm tapping but that did't get it to break loose. I've tried the squeeze technique with regular open wrenches and if I go much more the corners are going to round over.

This was my daily driver for a long time but since I retired a couple of years ago it mostly just sits. That's probably why the fuel pump isn't happy. My 4Runner is rock solid reliable but I always like to have two reliable cars at any time.

 

[Roreri]

Flare nut wrench and penetrating oil and patience. Otherwise you’ll make an unholy mess of it. Ask me how I know.

 

[___Scott___]

Update:
Flare nut wrenches allowed me to use more force but were not enough to break the joint loose. The next step was CRC Freeze-Off. I couldn't find any locally so I had to get it from Amazon. That did the trick, sort of. I was able to break the joint loose but it turned less than a full turn before it started to bind up. I worked it back and forth for a while and got it a few more turns before it started to rain so I decided to call it quits for now. It's progress at least!

Just as an FYI, CRC Freeze-Off requires that you spray the stuck bolt for about 20 seconds to freeze it. That's a lot of penetrating oil splashing and dripping around. Be prepared with rags to catch and clean up the mess. Also, eye protection would be a good idea.

 

[RedCelicaTRD]

If the freeze-off doesn’t work, you could always try a torch…

I’ll see myself out!

 

[___Scott___]

It's time for a wrap-up on this saga.

So, as I backed the flare nut off it began to bind up. I worked it back and forth making tiny bits of progress and being careful not to round off the shoulders of the flare nut. I spent a lot of time doing this. That worked up to a point but eventually it just wouldn't go any more so of course I added more and more brute force until I rounded over the shoulders of the flare nut. The next step was vice grips but before resorting to that I got out the hammers and "tapped" on the coupler. Fortunately both side of the coupler (hard line and flex side) were free to turn so I was able to tap all around and loosen up whatever was causing the bind. As you can imagine the vice grips caused a terrible mess but I was able to finally get the coupler apart.

With that problem resolved the fuel tank was fairly easy to lower out of position with the help of my floor jack.

Next problem, RockAuto sent me the wrong pump.

The part number on the box was correct but it had the wrong pump inside. To RockAuto's credit, their return process was pretty easy.

I bought a different pump from a local O'Reilly's, it was $20 more but only set me back 30 minutes instead of dealing with a replacement from RockAuto.

It all went back together pretty easy. I cleaned the coupler threads good and applied a heavy dose of copper anti-seize compound (it's what I had readily available.) The coupler was still a little stiff going back together but I only needed small pliers to spin the flare nut in.

With everything back together, and inspected for leaks, I took it out for a test drive. To my surprise the engine pulls harder and just wants to rip. I wouldn't have expected a fuel pump to make any difference in that regard. One problem that didn't go away is that even though it idles perfectly at 750 rpm in the driveway, it drops to 550 rpm at stop signs. That problem was relatively new, correlating to the antics of a weak fuel pump that I expected a new fuel pump to solve.

In addition to the idle problem, something is draining the battery when it just sits. I suspect the alternator which is less than a year old. I haven't looked into it yet, I just disconnect the negative cable from the battery for now.