willie59
Administrator
Man, am I a happy camper to have a new topic section to post various repairs, tips, and tricks that others may find useful. I'll get things started here with a repair I had to do recently, something I've never done before. The boss wanted me to have injectors of a Mitsubishi 6D24 in a Kobelco SK480 rebuilt. Easy enough job, a task I've done many times before. But on this one, had a problem with #1 injector, it pulled the bronze injector cup out with injector. You can view what happened at post #11 of The Suck Bucket thread at this link:
https://www.heavyequipmentforums.com/showthread.php?t=20354
Typically, what you would do is remove the cylinder head, and send the head to a head rebuilder and have them go through it and install a new injector cup. And although this engine has an individual head for each cylinder, removing it would have been quite a project because Mitsu used studs for all the exhaust and intake manifold ports, meaning, they would have to be removed. Very rusted nuts and studs on the exhaust manifold, the whole deal would have been a time consuming mess, when all I need to do is install a new injector cup, and the bronze cup was available from Kobelco.
Fortunately for me, I happen to have a head rebuilder very near me. I got a new cup from Kobelco, and made a little trip to talk to the fellas at Diesel Head and Parts, where they were kind enough to give me some info and a little crash course on how this process works. And they provided me with a supplier for a key part I needed to perform repair. A big shout out and many thanks to Earl and Darrell at Diesel Head for taking their work time to meet with me and provide me with much needed info. If I do need a head rebuilt, you can bet I'll be sending it to them and support them.
http://www.dieseldhp.com/
Well, let's get started with this repair.
Here's the hole in the head that I need to install a new bronze injector cup.
Here's the new bronze cup.
Now here's the trick. It's simple enough to drop the cup into the head, it will just drop in there. The coolant seal at the large end (outside end) is provided by the o-ring. The small tip end, which goes into the cylinder combustion chamber, is the end that requires special tooling to seal. According to Darrell at Diesel Head, it's actually quite simple, you have to use a tool that will expand the tip on the bronze cup by twenty thousandths, known as swaging, to seat and seal the tip in the head. Now, I could have got this tooling from Kobelco, at a cost of over $1,300.00 (not kidding), and that was dealer cost. Instead, the guys at Diesel Head provided me with a contact of a company that makes special tools for engine rebuilders where I was able to get the key tool I needed, that is, the ball broach. I contacted K-Line tools, and they referred me to a distributor in Alabama that provided me with the needed ball broach for $46.00 + ground shipping. Now that's what I'm talking about! Yes!
http://www.klineind.com/
Here's the ball broach. It's kinda hard to see, but on the end of the tool to the left side, you'll notice two bulges in the tool shaft, that would be the swaging balls. You simply drive this tool through the hole in the tip end of injector cup and it expands the tip. The first ball expands the tip by twenty thousandths, the second ball is an additional one thousandth to account for metal "flowback", or retraction, after the balls are driven through.
In the normal world, the head shop simply drives this tool through the cup, and pulls it out the bottom side. Well, my head is still on the engine, can't pull out the bottom side, I have to pull it back out the same way it went in. So I had a machine shop cut the 5/16" fine threads on the driving end of ball broach, and had them fabricate an installation clamping tool, that was over $900.00 from Kobelco (again, not kidding), that would press the cup in the head, set the o-ring, and hold cup in place while I drive the ball broach in and pull it back out. I also had machine shop fab a driving head to screw onto ball broach so I wouldn't damage threads while driving it in. Here's the tooling set up, all I have to do is drive the ball broach through far enough for second ball to punch through. The tool from K-Line was exactly enough, and no more, to get the job done.
https://www.heavyequipmentforums.com/showthread.php?t=20354
Typically, what you would do is remove the cylinder head, and send the head to a head rebuilder and have them go through it and install a new injector cup. And although this engine has an individual head for each cylinder, removing it would have been quite a project because Mitsu used studs for all the exhaust and intake manifold ports, meaning, they would have to be removed. Very rusted nuts and studs on the exhaust manifold, the whole deal would have been a time consuming mess, when all I need to do is install a new injector cup, and the bronze cup was available from Kobelco.
Fortunately for me, I happen to have a head rebuilder very near me. I got a new cup from Kobelco, and made a little trip to talk to the fellas at Diesel Head and Parts, where they were kind enough to give me some info and a little crash course on how this process works. And they provided me with a supplier for a key part I needed to perform repair. A big shout out and many thanks to Earl and Darrell at Diesel Head for taking their work time to meet with me and provide me with much needed info. If I do need a head rebuilt, you can bet I'll be sending it to them and support them.
http://www.dieseldhp.com/
Well, let's get started with this repair.
Here's the hole in the head that I need to install a new bronze injector cup.
Here's the new bronze cup.
Now here's the trick. It's simple enough to drop the cup into the head, it will just drop in there. The coolant seal at the large end (outside end) is provided by the o-ring. The small tip end, which goes into the cylinder combustion chamber, is the end that requires special tooling to seal. According to Darrell at Diesel Head, it's actually quite simple, you have to use a tool that will expand the tip on the bronze cup by twenty thousandths, known as swaging, to seat and seal the tip in the head. Now, I could have got this tooling from Kobelco, at a cost of over $1,300.00 (not kidding), and that was dealer cost. Instead, the guys at Diesel Head provided me with a contact of a company that makes special tools for engine rebuilders where I was able to get the key tool I needed, that is, the ball broach. I contacted K-Line tools, and they referred me to a distributor in Alabama that provided me with the needed ball broach for $46.00 + ground shipping. Now that's what I'm talking about! Yes!
http://www.klineind.com/
Here's the ball broach. It's kinda hard to see, but on the end of the tool to the left side, you'll notice two bulges in the tool shaft, that would be the swaging balls. You simply drive this tool through the hole in the tip end of injector cup and it expands the tip. The first ball expands the tip by twenty thousandths, the second ball is an additional one thousandth to account for metal "flowback", or retraction, after the balls are driven through.
In the normal world, the head shop simply drives this tool through the cup, and pulls it out the bottom side. Well, my head is still on the engine, can't pull out the bottom side, I have to pull it back out the same way it went in. So I had a machine shop cut the 5/16" fine threads on the driving end of ball broach, and had them fabricate an installation clamping tool, that was over $900.00 from Kobelco (again, not kidding), that would press the cup in the head, set the o-ring, and hold cup in place while I drive the ball broach in and pull it back out. I also had machine shop fab a driving head to screw onto ball broach so I wouldn't damage threads while driving it in. Here's the tooling set up, all I have to do is drive the ball broach through far enough for second ball to punch through. The tool from K-Line was exactly enough, and no more, to get the job done.
