450 crawler fuel filter clogged

[slwbid]

Just got the dozer. it started depowering and quit.
Changed fuel filters. Cranked and runs fine now except for 'surging'.
(wish I could type in the sounds like a little boy reving up his toy truck)
It speeds up and slows down very regularly....works find (rpms don't drop enough to affect permformance), but it is a nuscience and did not do it before filter change.


Any ideas appreciated.

Respectfully
Stacy Whetzell

[jtrichard]

How long have you ran it since the filter change? I have had some machines take a few HRS. of running to clear back up after filter change

[DrLoch]

Could also be the governor ring inside the pump. Did the fuel filter appear to be totally blocked?

To check if it may indeed be the pellathane ring of the governor coming apart remove the timing cover off the side of the injector pump and see if there are what looks like mouse turds in there.

[jtrichard]

Another thing ..see if after running for awhile if there is any vacuum in the fuel tank (pull the cap) the vent on the tank could be plugged

[B Town]

X2 on what jtrichard said. Run a small semi rigid wire through the vent. It is the 1/8 pipe just under the fuel cap. It runs through the tank and exits the bottom of the tank. You can ask me how I know about this! Bruce

[slwbid]

Bruce, how do you know about the vent pipe

I've ran it about 1 hour since filter change

while not totally plugged, the filters were very dirty....enough so that it shut the dozer off quite suddenly.

I filled the fuel tank just prior to changing the filter, so a plugged vent line sounds like a distinct possibility (not much room for air inside the tank)

I will check tomorrow. thanks so much.

Hope to not find mouse turds... chipmunks already ate wiring in an excavator and a welding machine. I was hoping to find a small handheld thermonuclear device with which to deal with the chipmunks, but alas they were temporarily out of 'em down at my local hardware store, so I had to settle for a shotgun and bird shot.

[B Town]

Out of the blue, my 450C track loader started to run poorly. It started acting up after i was using it for 1/2 hour, it had been setting for 1-2 days. It returned to normal when I loosened the fuel cap to check the fuel level. I found one of those mud nests from a wasp under the fuel tank.

Because your filter was so dirty, i wonder if the bottom of your tank may be dirty? Could the filter(again)or fuel supply be blocked? Do you purge 1-2 cups of fuel regularly out of the fuel tank sump? The PO had neglected my sump drain. It took quite of bit to clear the drain and the bottom of the tank, but I feel much better having it work properly and draining a small amount routinely. Bruce

[slwbid]

I checked. There is no problem with my tank vent.

B Town. I bet you are right. This dozer is 45 to 50 years old. the "Gunk" in the glass bowl below filter, was black and looked like coarse sand. But I bet it is from years of rust inside the tank. I'll clean it out good and throw some magnets down in the tank and give that a try. Also, I already have another set of filters, so I'll put those on.
Bet that fixes it

thanks all
Stacy

[NWJD fan]

One of my 350's has a tubular screen inside the tank that the supply line draws through and it has caused surging or shut downs in the past.