Service difficulty report · Diaphragm · Robsin R44RAVENII

Difficulty date
October 23, 2007
Submitted
January 21, 2008
Operation
General aviation
Make and model
Robsin R44RAVENII
Aircraft time
902 hours
Engine
Lyc IO540AE1A5
Part
Diaphragm
Condition
Torn
Location
Fuel Pump
Part time
1,215 hours
Component
Fuel Pump · Lyc
Component part number
LW15473
Stage of operation
IN
How discovered
V
Nature of condition
K
Precautionary procedure
K

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

(CAN) FUEL PUMP CHANGED DUE TO EXTERNAL OIL LEAKAGE. THIS USER HAS HAD 14 OF THESE FUEL PUMPS FAIL OVER THE LAST 8 MONTHS. THIS WAS THE FIRST PUMP DIASSEMBLED. IT WAS QUITE EVIDENT THAT THE UPPER DIAPHRAM HAD RUPTURED. THE SIDE OF UPPER DIAPHRAM MATERIAL EXPOSED TO THE ENGINE OIL SHOWED A DEFINITE INDICATION OF DETERIORATION AND THE RUBBER MATERIAL BREAKING DOWN. WHEREAS THE MATERIAL ON THE FUEL SIDE SHOWS NO DETERIORATION, EXCEPT WHERE THE DIAPHRAM HAD TORN. THIS LEADS US TO WONDER IF THE FUEL COMPATIBLE DIAPHRAM MATERIAL IS NOT COMPATIBLE WITH THE W80 ENGINE OIL USED. (TC NR 20071024003)