Oil slinging out at v-pump

[PoAdeleted5]

30 hours SMOH, got a problem. I find an oil leak at the vacuum pump. It's leaking, not from the pad gasket, but through the drive coupling and it is slinging it out of the holes where the drive coupling is on the pump base. As the pump turns, it slings out all over the place, making quite a mess.

I'll call my engine shop on monday morning. I'm curious as to what might be the cause and how the drive is sealed internally and what is causing the problem. Prior to overhaul, the old pump came out perfectly dry.

 

[AdamZ]

Larry: Not an A&P ( Not even close) but do you have a wet vacuum pump? I ask b/c Arnold recently enlightened me regarding wet pumps. As I understand it the wet pumps last forever because they have metal vanes and unlike the dry pumps require liquid lubrication i.e. engine oil. The wet pumps will apparently always vent oil, usually as I understand it on the belly of the plane. Arnold has told me that FAA agents doing ramp checks will often mistake the vented oil as signs of an oil leak. So If you have a wet pump, ( installed at your recent overhaul) this could be the issue and it may not be a problem at all but rather normal functioning of a wet vacuum pump. PLEASE confirm this with your A&P or someone more knowledgeable than I.

 

[PoAdeleted5]

No, it is definitely a dry pump (a brand new one in fact) and the oil leak is definitely abnormal. It was dry for the first 20 hours of operation after engine overhaul. I noticed a drop of oil on it last week when I did an oil change, coming from the holes at the plastic drive coupling.

This weekend, it's a shower.

 

[Don Jones]

30 hours SMOH, got a problem. I find an oil leak at the vacuum pump. It's leaking, not from the pad gasket, but through the drive coupling and it is slinging it out of the holes where the drive coupling is on the pump base. As the pump turns, it slings out all over the place, making quite a mess.

I'll call my engine shop on monday morning. I'm curious as to what might be the cause and how the drive is sealed internally and what is causing the problem. Prior to overhaul, the old pump came out perfectly dry.

Sounds like the seal that is on the shaft coming out of the accesory cover. Should be a fairly easy fix as long as the shaft and the drive housing the shaft runs in is ok. At least that is the way it is on Lycomings, I am sure Continentals are similar.
Not an A&P, and I did not stay in a Holiday Inn last night, but I have had one of these apart.
Don

 

[ejensen]

Just had that happen to me. There is a seal on the drive shaft, not part of the pump but the driving gear on the engine. If the seal fails, oil creeps down the shaft and slings off the VP drive shaft. It took about 2 hours to remove the pump, adpater, and get at new seal pressed in.

Eric

 

[Tom-D]

Larry: Not an A&P ( Not even close) but do you have a wet vacuum pump? I ask b/c Arnold recently enlightened me regarding wet pumps. As I understand it the wet pumps last forever because they have metal vanes and unlike the dry pumps require liquid lubrication i.e. engine oil. The wet pumps will apparently always vent oil, usually as I understand it on the belly of the plane. Arnold has told me that FAA agents doing ramp checks will often mistake the vented oil as signs of an oil leak. So If you have a wet pump, ( installed at your recent overhaul) this could be the issue and it may not be a problem at all but rather normal functioning of a wet vacuum pump. PLEASE confirm this with your A&P or someone more knowledgeable than I.

Wet Vac pumps last forever because they are lubricated, not because the have metal vanes. They actually have carbon vanes, but they need to be plumbed correctly or they throw out more oil than a broken dry pump.

see pictures, of the old Pesco wet pump. this pump had well over 3500 hours on it, nothing wrong with it just dirty.

 

[Henning]

30 hours SMOH, got a problem. I find an oil leak at the vacuum pump. It's leaking, not from the pad gasket, but through the drive coupling and it is slinging it out of the holes where the drive coupling is on the pump base. As the pump turns, it slings out all over the place, making quite a mess.

I'll call my engine shop on monday morning. I'm curious as to what might be the cause and how the drive is sealed internally and what is causing the problem. Prior to overhaul, the old pump came out perfectly dry.

If it's a dry pump, it's probably the seal on the driveshaft/accessory case. If so, at 30 SMOH, it should be warranteed.