Hard to Remove Injector

[bodywash]

I am trying to replace an injector on my 84' JD 850. The old injector is proving impossible to pull out. I have tried threading a 6in bolt into the top of the injector and using it as a sort of slide hammer with a 5 lb weight. Still no luck. I am getting very frustrated. I would appreciate any and all suggestions. Also, I am not worried about saving the old injector - just need to get it out.

Thanks Scott

 

[v8dave]

I'm confused about your using a slide hammer. Are you trying to shock loosen what ever has frozen the injector threads? All injectors I'm aware of thread into the block, similar to a spark plug.

First call a [truck and/or tractor] fuel injection shop and ask their advice, a big shop will have run across this problem before. If you have the head off and you can get it to them, they may be able to extract the injector for you.

Get a deep wall impact socket that will drop over the injector and use an air impact wrench for all removal attempts. An impact socket will be a 6 point socket. Make sure to use a 6 (and not a 12 point) point socket, this will grip all points on the injector with less risk of rolling the corners over when you apply the excessive force required.

Try the usual frozen bolt tricks.
-Liberally apply penetrating oil, try to tighten the injector, if it moves at all then apply more penetrating oil and try rocking the injector back and forth.
-Use a heat gun to heat up the head/injector assembly (but not destroy the injector), apply your favorite penetrating oil, try loosening hot and cool. Repeat using every penetrating oil you can get your hands on. Penetrating oils: Liquid wrench, Marvel Mystery oil, kerosene, and ?? others will add to this list.
-Use a torch to heat the whole head injector assembly, get it really hot (which will destroy the injector), apply wax to frozen area, let cool. Cooling will suck the wax in and lubricate the threads. Careful, excessive heat like this could damage the cylinder head. At a minimum, check the head for flatness, it may need resurfacing.

Be patient--most frozen thread clearing tricks with penetrating oils take a day to soak in, sometimes a week, in order to see if they are going to work.

 

[bodywash]

Thanks Dave,

The injector on this tractor does not thread into place. Rather it seems to be a friction fit - and it has a removable bracket with two bolts holding it in place. I have removed the bracket, now just trying to litterally pull the injector out of the cylinder. So any advice is welcome - even if it means destroying the injector.

thanks

scott

 

[mark777]

Scott, your right they can be a real pain.

What we do is saturate the base of the injectors with good quality penetrating oil, let sit over night and fit the appropriate end wrench on the flats of the injector. Strike the wrench with a large shot filled hammer and shock the injector loose.

We also shop vac around the base after the injectors are 3/4's of the way out to make sure no debris falls into the cylinders.

Good luck, Mark

 

[Dargo]

I have never changed the injectors on a tractor, but I have on a Cummins diesel. I had one injector that just would not come out. The Cummins diesel have a little detent that holds the injector in place and keeps it from turning. Apparently this one had gotten turned a little. Until I managed to get it aligned with the detent it wouldn't come out. After soaking it for literally days with WD40, I managed to get it turned the 1/16 of a turn or so to line it up. Then I still had to rig a slide hammer setup to get it out. Once out, I found that I didn't even damage the injector. I didn't have to worry about it either way, as I was putting in some slightly bigger injectors. /forums/images/graemlins/cool.gif
Good luck with yours. You may want to check to see if there is a little ball detent setup like I had on the Cummins. If so, it sure made a difference for me getting it out.

 

[RoyJackson]

"We also shop vac around the base after the injectors are 3/4's of the way out to make sure no debris falls into the cylinders."

That's a good comment...

Injectors and glow plug threads tend to get sooted up from unburned fuel.

Never had to pull an injector from a tractor, but have done it on a few Mercedes.

Penetrating oil and patience..also, try tightening them a bit first. Sometimes, that helps break 'em loose.

I see the original poster mentioned a "friction" fit. Not sure about this due to the higher pressures in a diesel engine. If the service manual isn't avilable, a trip to a dealer's service dept. might be worthwhile.

The injectors I've seen had at least a few threads to hold them in place... Doesn't mean that's the case here, but it's worthwhile to find out.

Good luck!

 

[CMunger]

When replacing the injector coat it with Never-Seeze, and it will come out effortlessly next time.
Chuck M.

 

[bodywash]

Thanks for the reponses.
On this injector, there is a bracket that fits over the top of the injector - bolted down with a stud on either side of the injector- to keep the injector in place.
I have a replacement injector assembly - and there are no threads. I also purchased a shop manual - basically the operation is to remove the lines, remove the bracket, and pull out the injector. Suggests using a puller if needed. The stud posts on either side of the injector make it impossible to put a wrench on the injector to turn it.
The fuel return line threads into the top of the injector. I have replaced that small bolt with a 6 inch long bolt (this bolt is only 8mm) and have used a 5 lb weight on it as sort of a slide hammer to try to jolt the injector loose. No good so far. I will continue to try penetrating oils. Also, I was thinking about unscrewing the top off the injector assembly then taking it to a welding shop to maybe have a larger diameter and longer shaft attached to top end of it. Then using this assembly as a larger and heavier duty slide hammer. Hope this does not sound too crazy. Just hope I do not have to spend my winter going out to the barn and beating on my tractor every nite just to remove an injector. This seems like it sould not be so hard.

Thanks again for all your help

Scott

 

[alvanko]

Try this..............
Reinstall the retaining bracket but leave it loose . Crank the engine over . The high compression of the deisel should "push" it out . I have never tried this have been told it will work .Soak it good with PB Blaster the night before.

 

[normde2001]

I was going to suggest the same as alvanko. The Yanmar injectors mount the same way and that's what has been suggested. Ditto on the "PB Blaster".