Join Date: Aug 2012
Location: South Central Manitoba
Mentioned: 0 Post(s)
Quoted: 167 Post(s)
5020 Ventilator Pump
I always wonder when I'm posting if I'm in the right section... not sure if it belongs in "Tractors" or "Antiques". I have an early series 5020 (1968 vintage) with the air pump on the front right side of the engine (called a ventilator pump in the parts book). About 4 yrs ago it started pumping oil so I took it into the dealer. They plugged the air line to the manifold with a ball bearing and told me not to worry about it. The pump apparently didn't do much and was discontinued on the later models. I did notice that occasionally when I idled down hot after that, the oil light flickered at idle like the pressure wasn't as high as it should be. The gauge looked normal while running.
Fast forward to last week, everything is running fine, but after sitting around a few days I thought the dipstick level was going up. The last time I serviced the injection pump, it took a couple front seals at the pump to get things sealed up, so I thought it might be leaking again. In the process of dropping some oil to take a sample for analysis, I noticed the oil wasn't coming out freely, and being male, poked my finger in the oil drain and some serious chunks of metal came out. It appeared to be pieces of timing gear, so off came the oil pan (more shrapnel under the pickup screen) and the timing cover.
There is a gear on the front of the Ventilator Pump that has lost teeth, and an idler that drives it that is ground almost smooth on one side. The good news is that all the other timing gears and drives for the injection pump look good, but if enough metal was floating around to ruin one seal, chances are there is more internal damage. How far we go is still up in the air ( it wasn't burning oil or leaking antifreeze anywhere prior to this) but my question is how do I deal with the 2 worn gears? If later 5020's didn't have the ventilator pump, can I simply remove the idler gear assembly or will that affect oil flow? Wondering if that might be the culprit with my oil light flickering at hot idle. There appears to be an eccentric and an oil galley at the base of it that makes me wonder if it is some kind of auxillary pump for just the ventilator pump, or does it feed other components as well? Anyone know what was in there for the later models with no pump?