since 1940

Wet Vacuum Pump Frequently Asked Questions

What is an Eclipse wet vacuum pump

The Eclipse is a very early, obsolete, hard-to-get-parts pump. Check your Type Certificate but you should be able to replace it with a Pesco or Garwin, such as the G-455


 

I have a Weston G-455. Is the same as a Garwin G-455?

Yes, Weston purchased Garwin and started casting their name on the pump. Otherwise Garwin and Weston pump is the same.

Installation tips?

Follow the manufacturer's maintenance manual

Check for oil leaks after installation

Here is a TO document we came across concerning installing wet vacuum pumps.

Wet pump installation tip(273 KB)

The enclosed program is a viewer program in .exe format. Download it and run the program. There is no installation program required. There are no other programs or modifications to the computer registry. When you want to uninstall , just delete the file. This is a very simple program, that is why we use it.

Coupling Identification

All vacuum pumps wet or dry on Continental and Lycoming horizontally opposed engines use the same 12 tooth splined shaft.

Sometimes your old coupling will have worn the teeth to a sharp point and it will look like a different coupling

Some couplings may be worn real bad!

Sometimes when you pull the pump out of the engine the coupling stays in the engine and the pump looks like this.  In this case you need to pull the coupling out of the engine.

Some other brands of wet vacuum pumps use different drive couplings shown below

Dry vacuum pumps use a plastic coupling like the Airborne style shown below

shown after it has sheared apart due to a vacuum pump failure

Difference between Garwin G450 or G455 and Pesco 3P194F vacuum pump

Both the Garwin G-450 or G-455 and the 3P194F vacuum pumps are functionally interchangeable

Photo of Garwin G-450

Photo of Pesco 3P194F

Rear view of Pesco 3P194F on left and Garwin G-455 on right

What is the difference between G450 and the G455 vacuum pump

The G450 vacuum pump has a port for cold weather oil dilution otherwise they are interchangeable.

Photo of G-450

Photo of G-455

Do your Garwin or Pesco vacuum pumps include a NEW metal drive coupling

Yes, for maximum service life from your pump and coupling we include a new coupling with each pump. You don't want to install a new pump with a used coupling!

Notice the flat teeth on the new coupling.




Worn couplings are often rusty and have teeth that have worn to a point, distorted and bent

All vacuum pumps have 12 point drive couplings. Different pumps have different shear strength couplings but the drive ends are the same.

Sometimes when you pull off the old pump the drive gear stays in the adapter. You need to remove the drive gear from the adapter. Sometimes it gets stuck because the teeth on the drive gear wear into grooves in the companion gear. Move the drive gear back and forth and jiggle it a little to unmated the teeth.

Why do I get short life on my wet pump? I thought they were more durable than dry pumps

If the oil seal in the adapter pad is leaking oil into the pump, the pump will fail very quickly. Since there
are no external signs of oil leakage you are unaware that this is occurring. If you are replacing a low time
pump play it safe and assume that the oil seal was leaking and replace it.

As a generalization wet vacuum pumps last longer than dry vacuum pumps. Compare the carbon vanes below. The thick one on top is the vane used on a Garwin G-455 wet pump, the small thin vane on the bottom is from an Airborne 211CC vacuum pump.

What does the PM refer to? For example G-455 PM vacuum pump

PM was a Cessna designation for a pump with a plastic drive coupling. Plastic drive couplings are no
longer used and replaced with metal couplings so the PM designation can be ignored.

Does the G-455 or 3P194 vacuum pump run both directions i.e. will it work on a Lycoming and a Continental

The Garwin G-450 G-455 or the Pesco 3P194F vacuum pump will turn either direction. The outlet ports have arrows on them so that you can get the correct hose hooked to the correct port.

Copyright 2003 by Sacramento Sky Ranch Inc. All rights reserved.  Prices subject to change without notice. Not responsible for typographical or misprint.
Disclaimer: sacskyranch.com contains abundant information relating to aircraft maintenance. The information provided  is not intended to supercede or supplement the F.A.A. approved  maintenance and/or operator’s manuals. Those F.A.A. approved manuals must be utilized when performing maintenance and/or operating aircraft.