AUXILIRY PUMPS M5

[g5280]

Can anyone tell me how to replace both light bulbs that should light up when the auxiliary wing fuel tanks are turned on, nether light works, however both pumps work fine? Maybe fuse? I would operate any help.
1977 M5 235hp
P.S Hallow Jeremy

[maules.com]

Grab the green plastic rocker face of the switch and pull straight towards you. Bulb then pulls out and can be replaced.
If its the old round style, it's a different removal.

[jmtgt]

Ok Jeremy how do you get the older round style out?

John

[maules.com]

If the round green light looks like the red stall warning light, then it has raised ears of bendable plastic behind the panel. Pull the whole light forward with a bit of twist action. The bulb is not replaceable but the assembly is and can be bought at Radio Shack for about $3. Maule has the red in stock but not the green just now.

[g5280]

Thank's Jeremy

[donknee]

I have the older round indicator lamps. They are somewhat dim and hard to see in bright sunlight...but workable.

[maules.com]

Even the new square ones are hard to see in sunlight but if not, both old and new produce too much light at night.
By the way, these indicater lights only tell you the switch is on, they do not prove the fuel is flowing, and, if the switch is on but the light is not, it does not mean the pump does'nt work, maybe the bulb is bad.
Generally 0.4 gals per min/pump and watch the guages. One pump will pump faster than the other, also with pumps off and tanks selected 'both' one side will empty faster.
Can a reader answer this phenomena with the correct reason?

[donknee]

Jeremy- Your query has piqued my interest. One way of determining the efficiency of flow would be to examine the "horsepower" required to pump that fuel. (.74 x gpm) x total head in feet
HP = ___________________________
3960
The diaphragm pump has a constant volume per stroke, a fuller tank= greater head pressure on the supply side of the pump (since pump is mounted below tank) = less horsepower required per stroke = more strokes per minute = greater efficiency and the ability to pump a larger volume, however that efficiency tends to decrease as the tank empties.
Alternatively, the resistence or head on the output side of the pump presents several scenarios, too. Depending on whether the pump discharges into the top or bottom of the tank, or the "one hung low" where one wing is lower because of weight distribution or flying technique. Either way one side will have an advantage and the other will have more resistence.

Another theory is similar to the coriolis effect....the Ainsworth Effect.

Probably a most plausable cause for unequal distribution or flow is the result of poor venting. Spiders, bees and other insects can create obstructions in the vent lines which interfere with the fuel flow, whether pumped or gravity fed and would allow uneven flow even in "both" with even wings. Other inefficiencies can occur with the check valves in the aux fuel pump. Debris or mung in the fuel can interfere with the check valve.

Any other thoughts? (

Don

[donknee]

(.74xgpm)x total head in feet
HP =___________________________
3960

This is a little better representation of the formula, sorry.

[maules.com]

Nope!

[g5280]

Nope ! Nope !! Jeremy this sounded wonderful to me cuz I don’t have a clue. All write why????

[maules.com]

I can't tell yet, someone might have a different answer to mine.
Soon come, if no one works it out.
A hint, on an old English engine, the other tank would empty faster.

[rjb]

In Cessnas, if you don't lean well, you will get uneven
draw and one side will empty sooner. As a soon to be
Maule owner, I can only extrapolate that this might be
the reason. Never noticed in a Citabria or Husky.

[maules.com]

Why would leaning properly or not change how the fuel comes from the tanks on a Cessna, or do I misunderstand.

[donknee]

Welll, I was right about one thing...it is sort of like the coriolis effect, then.