Installation of new AF Perf fuel pump

[gear1]

After nearly 1800 hours of operation of our RV8, the original Airflow Performance boost pump has become increasingly noisy. It has finally gotten loud enough to cause concern, so rather than waiting for failure I decided to change the pump. The new pump is the Air Flow Performance #2090255, sold by Van's as "EF Airflow Fuel Pump-1." The new pump has vastly simplified the installation, as the bypass is internal to the assembly, eliminating the return line to a "T" at the fuel selector valve. The installation eliminated seven fittings and about 18" of fuel line. A very nice assembly! The photos show how neat it is:







The photos of the fuel filter are a bit confusing. The line comes out the bottom of the fuel selector valve, and curves around to the back of the filter.

[RV7AJeremy]

Sort of a parallel thread going on at the same time:
http://www.vansairforce.com/communit...d.php?t=118171

[Mike S]

Other than the fuel lines, is there anything supporting the weight (mass) of the filter??

[Bavafa]

Originally Posted by Mike S

Other than the fuel lines, is there anything supporting the weight (mass) of the filter??

Exactly my thought. I saw a similar setup in another 8, only with longer fuel lines on each end with the filter suspended by the hard aluminum lines and pointed out my concern to the builder. He did not seem to have much concern about it though.

[gear1]

Good eye, Mike and Mehrdad,

I did not put in place the soft rubber cradles that will be used to support and damp the vibration of the filter. The cradles will support each end of the filter.

As I was removing the original plumbing for the pump, I discovered that the aft end of filter was rigidly attached (through several fittings) to the fuel selector valve, and flexibly at the front by the aluminum pipe going through the grommet in the gear tower. To me that was asking for fatigue problems at the fittings, although 1800 airframe hours seems to have shown that it works! Now, all of the lines are formed to be long enough to have a bit of flex to fend off vibration without overstress. The rubber cradles will provide the support and damping needed to protect the lines, and can be slipped out to allow for the filter to be removed at condition inspection time.

Thanks for the good observation!

[chazking]

We're you experimenting before "finalizing" the configuration? Better to see how it works than to re-do it later!