ventilator pump

[a49deere]

Can someone explain the basic operation of a ventilator pump on a 47 A and also the symptoms of a faulty one! Thanks in advance.

 

[wore out]

(quoted from post at 06:14:42 03/05/22) Can someone explain the basic operation of a ventilator pump on a 47 A and also the symptoms of a faulty one! Thanks in advance.

The ventilator (vane) pump pulls in fresh filtered air after the aircleaner and moves it into the crankcase, forcing "blowby" gases/moisture out the crankcase breather.

Failure (IIRC) can result in a possible oil leak at the fan and possibly increased "oil burning" by the engine.

 

[fdt860]

Why did john deere remove them for the second gen 20 series?

 

[wore out]

(quoted from post at 10:51:54 03/05/22) Why did john deere remove them for the second gen 20 series?

MY GUESS would be the availability of better detergent motor oils.

 

[pete 23]

Around this part of the country, some engine failures usually due to tractor running during snowstorm, plugging the air cleaner and then the oil from crankcase is sucked up into the engine. Usually happened when tractor was running a generator due to electric power failure.

We took them off at the dealer. Well, not off, just the gear and lines. Also, have to plug the oil pressure feed where pump mounts or you will have very low oil pressure at low engine speeds.

Me , being a IH mechanic most of my life never got the full story until I worked at Deere dealer last four years before I retired. Found one tractor with poor oil pressure and traced it down to the oil feed hole to vent pump not being plugged.

 

[JIM MN]

The ventilator pump on the fan shaft of a 1947 A draws engine piston blow-by gases from the
crankcase and pushes gases into a pipe up to the intake elbow in front of the carburetor so gases are
burnt a second time, reducing pollution.. Problem can occur?? This vent pump if original, had vane, two
springs and a retainer.. If any piece broke; the tractor would suck oil out of the governor housing ; not
air, up the tube to carburetor elbow and burn the oil.. Tractor burning too much engine oil..
On the new-generation tractors the same thing happened.. Wore-out vent pump bearing , too much oil , vent
pump vanes put oil into intake manifold, not air; burning engine oil.. Take off pipe vent pump to
intake manifold, problem solved..

 

[a49deere]

so oil blowing out of front of fan shaft could be a plugged vent tube to intake or just a bad fan shaft seal?

 

[a49deere]

wore out and Jim MN you guys are giving me conflicting answers. So does it pull air out of crankcase or push air into crankcase? Thanks

 

[J.Wondergem]

I'd think that you sure wouldn't want to pressurize the crank case.

Unless it's a two stroke.

This post was edited by J.Wondergem on 03/06/2022 at 06:40 am.

 

[55deere70]

(quoted from post at 20:18:33 03/05/22) so oil blowing out of front of fan shaft could be a plugged vent tube to intake or just a bad fan shaft seal?

Yes, that is a symptom of a problem with the ventilator pump. sometimes it's just the drain at the bottom of the pump that's plugged. No oil should be making it up the fan shaft in any case.