Author Topic: what is the correct fuel pump impeller orientation?  (Read 1549 times)

roymil

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what is the correct fuel pump impeller orientation?
« on: April 17, 2023, 00:46:45 »
i've had my short pump apart to clean for a long time and after i've polished everything up and removed all of the faint scratches that made it obvious, I now cant be absolutely sure which way the impeller should be installed. 

Do the thicker sides of the blades go up, closer to the motor, or are they oriented down as I'm just guessing, toward the bottom cover?

thanks much, Mark
Mark Miller
1968 280SL
Rode in his pagoda's first mile.

Kevkeller

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Re: what is the correct fuel pump impeller orientation?
« Reply #1 on: April 17, 2023, 01:00:03 »
Thicker side to the bottom I’m pretty sure.
1970 280 SL

BaronYoungman

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Re: what is the correct fuel pump impeller orientation?
« Reply #2 on: June 03, 2023, 13:36:08 »
Yes thicker side down
Bob "Baron" Youngman
1971 280 SL silver  1 car 0 boxes
1983 500sec Wheeler Dealer AMG Widebody
1985 500sec Paris Autoshow AMG coupe
1994 320sl wifes car
1988 560sec  Japan "Yakuza Car"

BaronYoungman

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Re: what is the correct fuel pump impeller orientation?
« Reply #3 on: June 03, 2023, 14:19:56 »
Imagine it like a airplane propeller you are forcing the gas up from the bottom of pump, thick part up to top of pump. You will also see they have a slight angle to them also increasing this action. ( pay no attention to dog nose in picture).
Bob "Baron" Youngman
1971 280 SL silver  1 car 0 boxes
1983 500sec Wheeler Dealer AMG Widebody
1985 500sec Paris Autoshow AMG coupe
1994 320sl wifes car
1988 560sec  Japan "Yakuza Car"

Brandini

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Re: what is the correct fuel pump impeller orientation?
« Reply #4 on: June 03, 2023, 14:46:22 »
To piggyback off of this conversation I have the early long style pump and I'm having difficulty installing the key for the impeller.

Does anyone have recommendations for installing this back in place?

I found this video starting at about the 9:30 mark where he discusses this but doesn't show how to do it.

https://www.youtube.com/watch?v=DQ70I8gfdlQ
Brandon
1964 Mercedes 230SL - red
Seattle, WA

afibbe

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Re: what is the correct fuel pump impeller orientation?
« Reply #5 on: June 05, 2023, 22:47:09 »
I like the dog nose. It is always good to have a second paw when you need it.
Alex Fibbe
1966 230SL
USA, Cincinnati, OH

geobarb11@comcast.net

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Re: what is the correct fuel pump impeller orientation?
« Reply #6 on: November 16, 2023, 18:14:34 »
Put a small dab of grease or vaseline on the key to hold it in place while you replace the rotor. Just make sure the rotor has the thin side of the teeth facing the pump body