I need a tutorial from someone who understand the workings of a Bendix RS-5 fuel servo.
I'm getting air bubbles in the feed line from servo to divider and consequently horrible engine performance and idle. Substituting clear bing fuel hoses along the pipeline shows clear fuel into the servo, plenty of bubbles in the hose downstream of the servo. Seemingly the servo therefore is allowing air into the feed line. How is this possible?
There are no fuel leaks evident anywhere.
The inlet fitting joining hose to servo is not cracked (and the line holds pressure after shutdown so the O-ring seal is good).
Each line segment is evaluated using a clear hose substituting for the high pressure AN hose, not just introduced in series, to eliminate the possibility of the hose itself leaking.
It's not a heat issue boiling the fuel (aka vapor lock) since testing is done uncowled, hoses and components are fairly cool.
I'm wondering if somehow an internal gasket or seal or a crack in a metal component within the servo can allow air into the fuel line. Ideas from the brain trust?
John Siebold
I'm getting air bubbles in the feed line from servo to divider and consequently horrible engine performance and idle. Substituting clear bing fuel hoses along the pipeline shows clear fuel into the servo, plenty of bubbles in the hose downstream of the servo. Seemingly the servo therefore is allowing air into the feed line. How is this possible?
There are no fuel leaks evident anywhere.
The inlet fitting joining hose to servo is not cracked (and the line holds pressure after shutdown so the O-ring seal is good).
Each line segment is evaluated using a clear hose substituting for the high pressure AN hose, not just introduced in series, to eliminate the possibility of the hose itself leaking.
It's not a heat issue boiling the fuel (aka vapor lock) since testing is done uncowled, hoses and components are fairly cool.
I'm wondering if somehow an internal gasket or seal or a crack in a metal component within the servo can allow air into the fuel line. Ideas from the brain trust?
John Siebold