Diesel Compression Tester for Yanmar 3TNE88

[Mechanos]

Rained out on my project, so I thought I do some prep for the compression test. Fabricated a hold down plate for the compression tester adapter and tried to pull one of the injectors just to see if I could get it out. Couldn't get it to budge without a puller, so I'll have to work up a puller to use with my slide hammer. The only thing to attach the puller to is the threads for the fuel line fitting. I don't have a spare fuel line fitting so I'll need to come up with something else to thread onto the injector. So far, I haven't been able to figure out what the thread size and pitch is on the injector.

 

[Mechanos]

Gave up trying to determine the thread size on the injectors and just ordered the Yanmar injector puller tool. Should be here in about a week. In the mean-time, I'm just twiddling my thumbs... still rained out on the project and this would be the perfect time to be fiddling with the tractor, but I can't even do that until the tools come in.

 

[dfkrug]

The only thing to attach the puller to is the threads for the fuel line fitting.
I don't have a spare fuel line fitting so I'll need to come up with something else to thread onto the injector.

All these injectors are hard to remove, in my experience. I left the fuel line installed and pried
carefully on it to get it started, then removed the line. This gave me something to grab with a
small vise-grips to turn the injector, while prying on the vise-grips. Of course, my engine was
out, so I had all sorts of working room.

There is a seal at the bottom of the injector hole that sometimes comes out with the injector,
and sometimes not.

Good luck.

 

[Mechanos]

All these injectors are hard to remove, in my experience. I left the fuel line installed and pried
carefully on it to get it started, then removed the line. This gave me something to grab with a
small vise-grips to turn the injector, while prying on the vise-grips. Of course, my engine was
out, so I had all sorts of working room.

There is a seal at the bottom of the injector hole that sometimes comes out with the injector,
and sometimes not.

Good luck.

Thanks for the info. Is the seal a copper washer type seal? Do you know if they typically need to be replaced when an injector is pulled? Or can they be re-used?

I've been spraying the injectors with penetrating oil hoping to loosen them up in their bores. Hopefully the puller & slide hammer will make short work of them.

 

[dfkrug]

Is the seal a copper washer type seal? Do you know if they
typically need to be replaced when an injector is pulled? Or can they be re-used?

They were some kinda plastic, as I recall. I installed all new in one case, and re-used in
another. If they don't come out with the injector, I do not know how you get them
out without damaging them. "Standard" engine re-build guidelines prob call for
replacing, but I had no problems re-using the old ones. If you are going to order a
bunch of other parts, I would get new ones.

 

[Mechanos]

They were some kinda plastic, as I recall. I installed all new in one case, and re-used in
another. If they don't come out with the injector, I do not know how you get them
out without damaging them. "Standard" engine re-build guidelines prob call for
replacing, but I had no problems re-using the old ones. If you are going to order a
bunch of other parts, I would get new ones.

I agree. For now, I am just wanting to perform a compression test and a leak down test, but wasn't sure if the seals were reusable. If the head has to come off, then new seals would be installed. Thanks

 

[Mechanos]

Got a call from the Yanmar dealer... my injector puller came in. Picked it up today and there was little unmentioned surprise. They didn't bother to tell me that there was a freight charge for them to order it in on the stock order, so my $33 puller ended up costing $50 with freight and tax. Just like getting stuff from JD, it's a rediculous price for what it is... basically it's just a coupler nut that has been bored out on one end and re-threaded to screw onto the injector. The slide hammer threads into the other end. Now if I could just get the dang compression tester adapter. It's on back-order so I'm still waiting.......

 

[Mechanos]

I got tired of getting jacked around by the company with the back-ordered adapter... they would give me a date, then when I'd call, they'd push it back again. Cancelled that order and found another place that had one in-stock and ordered it.

 

[6t6cuda]

I got tired of getting jacked around by the company with the back-ordered adapter... they would give me a date, then when I'd call, they'd push it back again. Cancelled that order and found another place that had one in-stock and ordered it.

I am looking to do the same thing on my 4TN82 Yanmar - where did you get the adapter and what compression tester did you use - diesels are new to me - spark plugs are much easier...

Thanks in advance!

 

[coloradotrout]

Would this work -- 12 Piece Diesel Engine Compression Tester

This one -- Diesel Compression Tester Set - 14 Piece -- seems to have the tractor adapters but costs $125 more. I have a Yanmar 3TNE74 - 3 cyclinder.