450C slows and stops, new injection pump and hour meter

[DBCSteve]

Over about 20 minutes while clearing brush, my 450C dozer slowed and the throttle stopped being responsive. I was able to limp most of the way back to the barn, finally stopping when I could not get the tach over 1000 rpm even at full throttle.

Checked air filters, fuel lines, even replaced the fuel booster pump. My local ex-JD mechanic Ron figured out and solved the problem in 45 minutes -- a plugged check valve at the injection pump. Just a bit of organic matter that kept the ball valve open, so I was recycling fuel back into the tank and starving the engine. We drained the injection pump to see if there was more debris. Nothing more, and no evidence of a plastic governor self-destructing. Dozer runs even better than before, so the check valve might have been partially clogged before. Ron figured the prior owner might have done some field work on the injection pump or fuel lines and did not keep things clean.

I'm back to clearing brush and movin' dirt.

[DBCSteve]

Turns out my fix was not permanent. Had the same problem repeated two more times, but at least I knew how to solve it to get the dozer back in operation and eventually back to the barn. No crap coming into the injector pump since the filter is new and clean, and the injector pump intake screen is clean. So the fouling of the return line check valve is from something disintegrating inside the pump. Based on various articles on this great forum (thanks again, Lavoy!), looks like I gotta rebuild the pump. Culprit may be the flexible governor weight retaining ring.

The good news is I pushed so many trees down that it will take a couple weeks of chain sawing before I need the dozer again.

As one of our regulars says, there is no such thing as a cheap crawler.

Steve

[DBCSteve]

Here are pictures of my old and new injection pumps. Same model Stanadyne. Got it from Diamond Diesel in northern California. Great tech advice and price.

I also took the time to put in a new hour meter. The original along with the frame plate it would have been mounted to were gone when I bought it last year. Took out the cigarette lighter in the dash, cut a bigger hole and wired it in with a 10 amp in line fuse.

Old pump --
http://i1210.photobucket.com/albums/cc4 ... G_3948.jpg

New pump --
http://i1210.photobucket.com/albums/cc4 ... G_3958.jpg

New hour meter --
http://i1210.photobucket.com/albums/cc4 ... G_3962.jpg

[tjdub]

Thanks for the photos Steve.

I read your post a couple of weeks ago and I have to say it was going though my mind when was I was going through the same problem with my 450 last week. Luckily, in my case, it was just the -15F temperature and some bad fuel filters. I guess you probably don't have to deal with that in California too often though