I've been living with an internal aneroid leak for quite a while, visible as a leak through the vent port on the back of the aneroid. Using this link as a reference, and Steve's (eggman) advice from the 4BTSwaps forum, I went and replaced it today. Talk about a PITA to replace an o-ring that's only 7mm in diameter!!
http://www.dieseltruckresource.com/dev/leaking-fuel-pin-o-ring-t244296.html
There was tons of evidence of old diesel in the aneroid, which appears to have caused a varnish to develop inside the aneroid. This was thoroughly cleaned.
While working, I also found a loose motor mount nut and a frayed throttle cable, both of which were fixed. Good thing I finally got around to this o-ring replacement!!
I'll spare you most of the boring disassembly/reassembly pictures and focus on the o-ring itself. After removing the top cover, you have to remove the central rod that holds the middle bracket, so that the fuel pin follower can be removed. To do so, you have to punch out two stupid ball bearings that Cummins decided to use as retainers for this shaft. Lots of cussing and a few bent punches later, she was out.
After that point, the cover and retainer nut for the fuel pin follower can be removed, followed by the fuel pin follower and the associated brackets/o-ring. The o-rings have the following dimensions:
Here you can see the fuel pin inside of its black holder, with a new o-ring and the brass cap. This assembly is slid into the aneroid:
Here you can see the installed fuel pin follower assembly:
Reassemble the top cover, reinstall the top cover onto the injection pump after thoroughly cleaning everything:
Varnish removed, all nice and clean:
When reinstalling the top cover, I realized that I had the throttle max travel screw turned way, way too far in, so much so that I was restricting throttle travel by a solid 20% (towards WOT), effectively meaning that I was never able to reach WOT. I readjusted and realized that now my pedal couldn't move far enough, so I removed the pedal stop from the floor insdie the truck, as I was replacing the frayed throttle cable.
Needless to say she runs after dissecting the motor's brain once again, but holy crap am I surprised how much better she runs.
I now hit 30psi by 2150rpm (maybe earlier, gauges moving so fast it's hard to tell) and max boost is up to 36psi. With the aneroid functioning properly now, I get a haze when under boost. Need to take some driving videos tomorrow so I can get a better idea how much there is. She is quite a bit more powerful too, judging by the seat of the pants dyno of course
I don't know why I waited so long to fix this problem, but damn, I'm glad its fixed now!!
In other news, Josh [MEMBER]cruiser guy[/MEMBER] sent me a set of 6 injectors from his motor swap/build project. He ended up having to replace his and sent me his old cores for free!!! I can't wait to get these rebuilt and installed. Thanks Josh!!!
Stay tuned, more updates to come tomorrow.