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Cat 320C low power

glennmackenzie ยท 2020-05-28 21:52

Hi all, One of my Cat 320C's is low on power when hydraulic system is working hard. Have had this before and has always been a problem with the fuel system (blocked banjo filter), but this time is different. Same symptoms as if it is starving for fuel but fuel lines and filters are clear all the way from tank to injector pump. Air filter is also clean. Can anyone give some advice on where to look next? Thanks in advance! Glenn

Replies6
  1. #1heymccall2020-05-28 22:11

    Serial number? Hours on machine?

  2. #2glennmackenzie2020-05-28 22:36

    HFBA00490 approx 22000hrs Had major rebuild and check over by CAT dealer in 2015 at 20000hrs but previous owner couldn't pay the bill so got auctioned off. I picked it up and this is the first issue I've had with it. Has been flawless otherwise

  3. #3heymccall2020-05-28 23:25

    I preach this all over the skid steer section, but that machine also uses the stanadyne fm100 water separator (1174089). It has two major issues that crop up. First is that when the water bowl is swapped from the old filter to new one, the O-ring tends to disappear. Since yours is below the fuel level, if the O-ring were missing, the bowl would be damp. But, when I get called out for that, the symptoms are the same, power loss under load. Second issue is that, since it is first in line in the tank supply to the engine, the inlet elbow and the internals get clogged with debris. I've had issues on new machines with less than a 1000 hours on the separator filter head. So, quick and dirty, bypass the water separator and run the machine through its paces, and see if it is better. Or, take the whole thing apart and clean it out. The top unscrews, but, I take the whole darned thing apart, as I've found blockage all the way into the concentric filter stem. I can link to the skidsteer thread(s) with pictures if need be.

  4. #4glennmackenzie2020-05-29 18:54

    Thanks for the reply but as per my post fuel is free flowing all the way to the injector pump. As a side note, the water seperator unit is brand new as the old one was so seized it broke the housing when I tried to remove it!

  5. #5latiff"2020-06-23 19:14

    Try pumping the prime pump while it's losing power,the secondary one first (the one directly on the engine) ,then followed by the one on the injector pump ,see if the engine revs up better than usual

  6. #6heymccall2020-06-23 21:04

    That's a 3066, which means there is a screen in one of the fuel banjo bolts, too.