Pump update for AndrewZ

Paul Shuler · Sep 1, 2010

Andrew, I took the pump off the ole super C last night. Having never looked in one of these things I wasnt sure what to look for. The part of the case the drive gear set in had some very light marks that you could not feel. The part of the case that the driven gear set in had a groove approx 1/2 way around the bore just deep enough to catch your thumb nail on. The only other thing I noticed was the drive gear and shaft could be moved in and out [not side to side] about an 1/8 of an inch. Did not know if this was normal or not.
Paul

El Toro · Sep 1, 2010

You may need to put a speedi-sleeve over that worn surface since that sometimes causes the hydraulic oil to get into the engine. That's item No11 and item No4 gets brittle and wears a groove on No11. Hal

Janicholson · Sep 1, 2010

Moving the drive gear in and out 1/8th inch is not good. The pump gear is thus free to move that amount. it should have leclose to or less than .0015" and more than .0008" axiel clearance between the pump gear and housing end frame. Jim

Paul Shuler · Sep 1, 2010

Would putting a rebuild kit in the pump do anything to help this or is it time for a new pump? Ouch!

Janicholson · Sep 1, 2010

If the end plates are worn and can be found (I think but do not know that they are the bushing plates as well! then that would do it. But worn gear thickness can't be fixed. Jim

Janicholson · Sep 1, 2010

If the end plates are worn and can be found (I think but do not know that they are the bushing plates as well! then that would do it. But worn gear thickness can't be fixed. Jim

JoeVT · Sep 1, 2010

The rebuild kit is just gaskets and seals. It wont help the movement in the drive shaft. As Jim suggests, check the brass bearings for wear. My pump is currently apart, i can mike the bearing when i get home tonite and report back if needed. Also check that the drive shaft has the proper bearing. The bearing for the drive shaft is longer than the bearing for the pump gear. It's remotely possible that the pump could have been serviced in the past and the wrong bearing installed. But i would think if it had the wrong bearing it would have done a lot of damage to the gear teeth.

Andrew Z · Sep 1, 2010

Paul, you can email me if your interested in the pump.

thanks

Andrew

IH fan · Sep 1, 2010

Not sure how the Pesco or Thompsons are, but on a Cessna, they have a pressure wear plate that presses against the gears as pressure increases to seal the sides of the gears. In the picture shown, I would think that #8 and 12 (Pesco) might do the same thing. 1/8" is way too much in a Cessna and probably in these too.

Pump update for AndrewZ

Paul Shuler

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El Toro

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Janicholson

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Paul Shuler

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Janicholson

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Janicholson

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JoeVT

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Andrew Z

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IH fan

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