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fuel pump install

BruceMe

Well Known Member
I got a new Tempest AF15473 high-pressure fuel pump. It came with vague installation instructions that had crapy drawings... Do I install it with the pump lobe in a position so that the pump is under the most compression or with the least compression?

Thanks,

-Bruce
 
Push up on the plunger while you rotate the prop. You want the position that leaves the plunger as high as possible. The less compression of the pump, the easier it is to install. It is critical the pump flange face remain parallel to the case while tightening the bolts. Else the arm can slip off the plunger. If concerned, you can pull the mag and use a mirror to observe this.

Larry
 
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Thanks... I pushed the plunger up, but I must have let it slip off the side, no pressure :| Hope I didn't bend it. Take 2 this evening
 
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To hold the plunger up, I removed the left magneto on my O-360. This made the job very easy. Well worth the time of reinstalling and timing the magneto.
 
To hold the plunger up, I removed the left magneto on my O-360. This made the job very easy. Well worth the time of reinstalling and timing the magneto.

I just did this a week ago. I have Pmags, and since re-timing them takes 10 seconds, it was much, much easier to it this way.

I did have to cut down an allen wrench to get to the fuel pump bolts. My hex head socket wasn't long enough and my allen wrench was too long.
 
Thanks... I pushed the plunger up, but I must have let it slip off the side, no pressure :| Hope I didn't bend it. Take 2 this evening

checking the pump lever should be easy. If it were me, I would pull the mag and be sure that you didn't crack the casting that the pushrod slides up and down inside of. Unlikely but possible.

Larry
 
Yeah... I pulled the left pmag, it all made sense. I had other issues, but it should be fixed soon.
 
I used .020 (thin) safety wire wrapped a couple times around the pushrod with enough length to easily hold the wire while installing the pump. The side load applied by the wire prevents the pushrod from falling down. Once the bolts are started, pull out the wire.
 
I did the 'safety wire' trick to hold the plunger up. (search it)
That way no need to remove mag/ignition (unless you want to).
 
Keep in mind that the bolt holes are drilled through and if you fail to seal the threads on the fuel pump bolts, they may leak oil.
 
I did finally get it installed. I started one bolt and wiggled the pump around till I could feel the plunger then pressed it into the case and finger tightened the bolts. Took a few tries, but I eventually got it. I'll need to find out about that safetywire trick next time.

But it's all installed now and running well and making good pressure.

Man I forgot how easy timing pmags is. That just takes all the PITA out of mag timing.
 
I just bought a Tempest Fuel Pump (AF-15473) from Aircraft Spruce online. It’s Sunday and they are closed.

Can anyone with recent experience tell me if the new pump comes with a gasket?

Thank you,
 
I did finally get it installed. I started one bolt and wiggled the pump around till I could feel the plunger then pressed it into the case and finger tightened the bolts. Took a few tries, but I eventually got it. I'll need to find out about that safetywire trick next time.

But it's all installed now and running well and making good pressure.

Man I forgot how easy timing pmags is. That just takes all the PITA out of mag timing.

Good excuse to comply with the pmag 100 hour inspection if nothing else.
 
new pump comes with a gasket?

replaced mine a month ago, and yes, it came with a gasket in the same box.

PS
Probably because I thought it wouldn't, and ordered a gasket along the pump... wish ACS would publish such detail in their descriptions, though reading their Q&As also helps ;)
 
replaced mine a month ago, and yes, it came with a gasket in the same box.

PS
Probably because I thought it wouldn't, and ordered a gasket along the pump... wish ACS would publish such detail in their descriptions, though reading their Q&As also helps ;)

Thanks for the response Dan.

I ordered the gasket because I wasn’t sure if one would come with the new pump. The gasket is back ordered.
 
I had to find an A&P on a Sunday afternoon in rural Iowa halfway through the 4-hour ferry flight as my CFI/buddy and I were bringing my just-purchased plane home a few years ago. He struggled mightily due to tight quarters (prop governor) and that stupid plunger. He didn’t know about the remove-the-pmag trick (nor did I) but was finally able to pull it off using safety wire to hold the lever down to get underneath the plunger, partially install the pump then cut and remove the wire before tightening the rest of the way.
 
Or This

Removing the magneto is a pretty foolproof way to to this but I’ve always smeared a gob of grease on the pin before pushing it up. Holds it long enough to get the pump in place.
 
In case ACS is closed, the fuel pump gasket is the same as a Pontiac V8 from 1955 to 1981. Probably various other GM applications as well.
 
Removing the magneto is a pretty foolproof way to to this but I’ve always smeared a gob of grease on the pin before pushing it up. Holds it long enough to get the pump in place.

This is what I generally do - replaced one last week using this technique, and it was very quick.
 
In case ACS is closed, the fuel pump gasket is the same as a Pontiac V8 from 1955 to 1981. Probably various other GM applications as well.

GM used the same fuel pump mounting flange design for decades, prior to the fuel injected era. The original aviation pumps (for carb'ed engines) even had the AC logo (as in AC Delco) stamped on them.

Larry
 
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I installed the new Tempest Fuel Pump (AF-15473) on my RV-8 (IO-360) today. The new pump did come with a new gasket and instructions how to complete the install.

My old fuel pump had 938 hours on it and was about 14-years old. It was producing 28 psi when it was removed. So why did I replace it? ‘‘Because I’m worth it,’’ a quote adopted from others.

The new Tempest fuel pump is producing 31 psi at idle. With the Airflow Performance electric fuel pump on, I see 33 psi at idle.

All new Teflon fuel hose’s installed.

Putting grease on the actuator rod seemed to help.

Thanks everyone for sharing your experiences.
 
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