Had the capsules tested at the local dealership in Stockton a couple days ago on Holt’s testing apparatus for my D6 8U. One good capsule, four that popped in spec but weren’t atomizing satisfactorily, and one bad. The gentleman helping me go through my machine insisted we all go watch the capsules being tested in person, because it was his experience in the past that most people testing them would call a capsule “good” and instruct someone to reuse it so long as it pops at the correct pressure and holds pressure like it’s supposed to, without giving much consideration to visual atomization. And I’m glad we took his advice and watched it in person, because the tech told us he would run a couple of them that weren’t up to my friend’s atomization standards. He worked in the service department there years ago with the tech that actually tested them for us.  We bought new capsules and had them tested. Big difference!  They even sounded different when they pop. They make a high pitched squeak when They pop and they’re good. I definitely got an education that day. I’m glad I’m going through this machine now. Holt’s tech that tested them is the only one there that knows how to do it, as relatively simple as it is. And he’s going to retire in a year. He said he used to rebuild at least one injection pump a week, but now he **maybe** does one per month, as everything modern is now computer controlled high pressure common rail. 

Today we opened the fuel tower. I don’t think you could put any more dirt in there. The filters have never been changed as long as we’ve owned it (easily 25 years). I really should have taken a picture to post how bad it was. I wanted to change the filters several years back, but against my better judgment, someone else convinced my father we didn’t need to because the pressure gauge read all the way in the green “normal” range. Ha! Anyhow, that prompted the gentleman helping me to want to drain the oil on the injection pump housing and open the side covers under the fuel pumps. A fair amount of of gritty crap was in there too and it was over-full. Some diesel had apparently seeped into there as well. 

We’re likely going to remove the fuel pumps and have them tested and I want to ensure proper rack settings once I put them back.  In researching settings and such, I came across an old post on here titled “capsule nozzles,” circa 2007.  EdB spoke of a couple of well-worn documents that he acquired copies of from the dealership he worked at that sounded like they were the holy grail of rack setting charts and data for many different models. I looked for them on the Technical Library but couldn’t find them. The documents mentioned in the post were Form 7272 and Form 30782, and Form 5683A.  Ed- if you see this and have a free minute, could you look through your document collection and see if you still have those somewhere and see if they can’t be added to the Technical Library?

Thanks!
-Nick

This is what I've got.Hope this is what you're looking for.info from FORM 7272-DGood luck 

the injection reference is one of those i come with it tools. the kind you never let out of your sight. lest some bastard steals it.a mate had a warren & brown torque wrench you could borrow it but only in his shed as it was a few hundred bucks to buy

This is all you need to know...

Thanks for all the replies. Last week we pulled the fuel pumps and had them tested by a local independent Cat mechanic that has the apparatus to do so. At first he thought they were shot because the numbers were so low, but he ended up having to run them three times to get all the crud out of them so they would work properly. They all ended up being in spec. It cost me a little bit to have him do it, but I suppose it was worth it to get them clean, and I think they are pretty time consuming to set up on the testing machine. ​​​​​​​Everything is about clean and ready to go back together. Started to clean out the fuel tank today. It got plugged up several times in the process with crud. The red dye looks more orange than red. I’m thinking I may have to send the tank out to be blasted and epoxy coated internally to eliminate the apparent rust/sediment issue. I used a local “gas tank renu” outfit a few years back on a military jeep fuel tank and they did a nice job and it’s worked wonders. I have a feeling it won’t come cheap as big and cumbersome as that tank will be for them to handle.   The mechanic with all the fuel testing equipment is going to come help us set the injection pump lifter settings. Book spec is 1.736 He wants to set it to his modified setting of 1.726   He claims this will advance it a touch and basically inject the fuel a touch earlier in the stroke and will give a more complete combustion and has a tendency to really wake these things up on the ones he's done in the past. Hopefully its a good move…..interested in your thoughts about this.

Finally, I'm kinda doing a bit of a photo dump....I tried doing it directly off the iphone, but it wouldn't play well with uploading the pics on the site last night so I'm giving it a go using a junky old laptop....

First of all, I have to show you the subject of all my posts lately.....pretty unique, I know   I don't know if I mentioned it in my previous posts, but we'll see if you can guess it's purpose:
 

3 of the 4 very dirty fuel filters:
 

Filter tower and lid:
 
 

Bottom cover of filter tower opened for cleaning:
 

New o-ring seal and new ferrule installed between filter tower and injection pump housing (note the guide bolts to help align the installation of the injection pump housing):
 

Not pictured, new lip seal installed on the back end of the injection pump camshaft where it mates to the filter tower.  Old seal was made of leather and was shot.

Thanks!
-Nick




 

Thanks for the pictures ... WOW !!!! That is a tall drink of water. One of the most interesting track rigs I've ever seen. Very nice.

You got it Neil! It’s to dig up our nursery trees. We have grown our own walnut trees for years. My dad had this machine put up when I was in grade-school. It drives over the trees and the U in the back cuts the roots. The plate welded in the U lifts them up out of the ground.

I drained the rest of the sour fuel from the tank today. It did not drain nearly as fast as it should have. Lots of sediment and crud obstructing the flow. I am hoping that with the fuel system all clean and flowing freely, this thing will have extra power previously unknown to us.