Kahuna
Moderatoring
Over the past 500 hours or so I have noticed a slow progressing need for the boost pump, culminating in fuel starvation and an uneventful landing on a recent cross country.
A check of the fuel line at the servo and boost pump on resulted in fuel shot across the ramp. Seemed fine. Test flight, and again fuel starvation.
A check of the fuel filter show nothing. Visually spotless. Until I tried to blow through it. Definite restriction. Cleaned filter with carb cleaner, and I could see a light yellow color in the solvent. Reassembled, and no restriction blowing through it. Problem solved. Flown another 10 hours until home with no need at all for the boost pump which is something I had not seen in years.
This is an AFP 40 micron filter. One of those 6ILA assemblies.
I checked the paperwork for cleaning instructions and "The filter element can be removed from the filter cap and cleaned in mineral spirits then blown dry with compressed air"
Hmm. "Can be"
Checked with a couple other high time experienced RV'ers, and they too had never run solvent through the filter.
With 2500 hours over 20 years on the filter, I have never done more than visual inspection, clean off any debris, and reinstalled. Never any solvent. I have no idea what had been building up in inside the element, but obviously something had. Also no indication in the docs about service life. Installed a new one.
Lesson?
1. Dont let a slow creeping issue go unresolved.
2. Clean the filter with solvent at annual.
3. After assembly, blow through the housing, it should blow quite freely.
A check of the fuel line at the servo and boost pump on resulted in fuel shot across the ramp. Seemed fine. Test flight, and again fuel starvation.
A check of the fuel filter show nothing. Visually spotless. Until I tried to blow through it. Definite restriction. Cleaned filter with carb cleaner, and I could see a light yellow color in the solvent. Reassembled, and no restriction blowing through it. Problem solved. Flown another 10 hours until home with no need at all for the boost pump which is something I had not seen in years.
This is an AFP 40 micron filter. One of those 6ILA assemblies.
I checked the paperwork for cleaning instructions and "The filter element can be removed from the filter cap and cleaned in mineral spirits then blown dry with compressed air"
Hmm. "Can be"
Checked with a couple other high time experienced RV'ers, and they too had never run solvent through the filter.
With 2500 hours over 20 years on the filter, I have never done more than visual inspection, clean off any debris, and reinstalled. Never any solvent. I have no idea what had been building up in inside the element, but obviously something had. Also no indication in the docs about service life. Installed a new one.
Lesson?
1. Dont let a slow creeping issue go unresolved.
2. Clean the filter with solvent at annual.
3. After assembly, blow through the housing, it should blow quite freely.