Correct Larry! (mostly!)
When I read your comments, I knew that my P337 did not have wet pumps - it actually does have Dry pumps with De-ice. Here is why:
From the Cessna Service Manual Page 14-9: The dry vacuum pumps are replaced with oil lubricated pumps and oil separators when the optional de-ice system is installed thru aircraft serials P3370052. Beginning with aircraft serials p3370053 and FP3370001 the vacuum pumps are replaced with larger capacity DRY vacuum pumps when the optional De-Ice System is installed.
So not all 337's have Wet pumps with de-ice - only those prior to serial 0053.
The service manual goes on to say
NO SUCTION INDICATED AT ONE SOURCE:
Probable Cause may be any of the following:
Defective Vacuum Pump - or
Disconnected, broken, or plugged lines - or
Defective relief valve - or
Defective suction guage.
It doen'nt mention the drive coupling - but that is also a great suggestion..
Let us know what you find!
Last edited by Pat Schmitz : 01-11-06 at 10:59 PM.
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