Injector Pulling Tool

[dkinzer]

The Yanmar 4JH4E in our 2007 H41AC has about 1200 hours on it so I'm working through the recommended 1000 hour service items. One of those is to have the injectors tested and their spray pattern evaluated. I saw that Yanmar has a special service tool for pulling the injectors (129470-92300) but it's pretty expensive at $180 or more.



Initially, I was planning to make a screw-based pulling tool like Yanmar's but I decided instead to make a slide-hammer type tool. The photos below show what I made using materials I had on hand in my shop. The threads on the top of my injectors are M12-1.5 so I put matching threads in the end of the puller, about 20mm deep.


I've also attached a short video of it in use.

 

[kappykaplan]

Initially, I was planning to make a screw-based pulling tool like Yanmar's but I decided instead to make a slide-hammer type tool. The photos below show what I made using materials I had on hand in my shop.

Necessity is the Mother of invention!

 

[jviss]

I'm confused, are the injectors pressed into the head? Why is a puller necessary? The only injectors I'm familiar with screw in like spark plugs.

 

[dkinzer]

From what I can tell, my injectors are a light press fit into the head - I couldn't pull them out by hand. There is a clamp piece that hold it in the head against the compression pressure. I've seen some videos of using the comperssion pressure to push the injector out.

 

[jviss]

From what I can tell, my injectors are a light press fit into the head - I couldn't pull them out by hand. There is a clamp piece that hold it in the head against the compression pressure. I've seen some videos of using the comperssion pressure to push the injector out.

Wow, that's interesting, and a surprise to me. I wonder why they did that?