Fuel pump no workie... LC no happie... Me so no luckie... New pump cost much monie...

Joined
Jul 16, 2022
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36
Location
Oklahoma
Yes, I agree my limerick writing ability is less capable then my fuel pump rebuilding ability...

Mine is an original '64 lever pancake, and after watching the CC rebuild youtube video I tore into mine and rebuilt it with new parts, retaining the original lever and spring. I'll admit to incorrectly clocking the top cover and had to trouble shoot that problem but finally got it working, kinda. Now, the truck idles great forever, responds wonderfully to throttle while sitting still, and motors around the yard in 1st and maybe 2nd gear for 5 minutes. However, on the road it won't go 1/2 mile without the pump failing. I'll hit 3rd gear and just start to tool along and then sputter, sputter, cough... Fuel bowl is dry.
I can pump the lever but get no result, UNLESS I loosen the top cover and cycle the pump a few times, then re-tighten the cover. After that procedure the pup works great again and I can go another 1/2 mile, then rinse and repeat...

The tank was boiled clean last week and I replaced the fuel filter. The pump rebuild happened last week also, as did a carb rebuild. I'm re-using the old fuel lines. I thought maybe the pump was pulling a vacuum in the tank, but this happens without a gas cap.

I'm suspecting I failed at the pump rebuild. Any suggestions? (besides replacing with a new pump) It's a pretty simple contraption, but I have been know to break a crowbar...

Many thanks!
 

red66toy

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Hi there! If you take the top cap off, can you confirm the little phenolic one way valves are working correctly? Loosening the top cover sounds like fuel is able to jump between the chambers, which makes me think the one-way valves might be the issue.
 
Joined
Jul 16, 2022
Messages
36
Location
Oklahoma
Hi there! If you take the top cap off, can you confirm the little phenolic one way valves are working correctly? Loosening the top cover sounds like fuel is able to jump between the chambers, which makes me think the one-way valves might be the issue.
Hey thanks for the reply, and thank you for the rebuild kit. I too wondered about those valves, but they seem to be working when I look at them. They respond correctly when I touch them, and with the top cover off I see them moving in the appropriate fashion when cycling the lever. I'm at a loss and am willing to admit that maybe it's not the pump at all but possibly a supply problem further upstream. However, that suggests maybe floating debris that settles during the down time and everything was previously washed clean. The pump is the only "complex" part up to the carb, so it's my first suspicion.

I was hoping maybe there was an obvious step I missed (like clocking the cover) that created these symptoms...
 

flx

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Jan 4, 2019
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France
Maybe check there is not a pinched hose between the fuel pump and tank. It could be pinched in a way that let pass a very small quantity of fuel for idle but when asking more it creates a vacuum and completely pinch until you release the pressure...
Maybe trying to blow the hose to check there is no gunk in them that could block the passage. Also hanging fuel filter if not already done.
 
Joined
Jul 16, 2022
Messages
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Location
Oklahoma
I believe I've located the problem. Thanks for the advice folks!! It's amazing what a good night's sleep and the light of day can do for finding these troubles. I left the rig in a secure location last night, albeit not clean. I'll need two showers tonight after crawling around tracing fuel lines. I imagine a few of my new itchy spots may be spider bite, scorpion stings, or other defensive attack from some other 12-legged "No-see'um" critter. Just glad I didn't find a Copperhead.

Long story short, I believe the fuel line is cracked somewhere along the frame. I got it running again, but light shining through the first fuel line at the filter revealed big air bubbles that didn't match at the tank output. Increased idle RPM just increased the quantity of bubbles, so I think that's pretty conclusive, plus the bowl would never fill due to the quantity of air. That's what prompted me to crawl under the beast, thinking I could find a wet spot where it ay be leaking, but the boxed frame Kept its' secrets hidden better than Victoria, so I'll just spring for a full set of new lines. I knew this would be an expensive venture, but Ouch...

More money than I wanted to spend on that particular issue, but it's still cheaper than therapy, my ex-wife, narcotics, or gambling, plus these rigs are appreciating faster than real estate. I think that makes it a good investment overall!
 

red66toy

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Joined
Feb 25, 2003
Messages
4,060
Location
Seattle, WA
I believe I've located the problem. Thanks for the advice folks!! It's amazing what a good night's sleep and the light of day can do for finding these troubles. I left the rig in a secure location last night, albeit not clean. I'll need two showers tonight after crawling around tracing fuel lines. I imagine a few of my new itchy spots may be spider bite, scorpion stings, or other defensive attack from some other 12-legged "No-see'um" critter. Just glad I didn't find a Copperhead.

Long story short, I believe the fuel line is cracked somewhere along the frame. I got it running again, but light shining through the first fuel line at the filter revealed big air bubbles that didn't match at the tank output. Increased idle RPM just increased the quantity of bubbles, so I think that's pretty conclusive, plus the bowl would never fill due to the quantity of air. That's what prompted me to crawl under the beast, thinking I could find a wet spot where it ay be leaking, but the boxed frame Kept its' secrets hidden better than Victoria, so I'll just spring for a full set of new lines. I knew this would be an expensive venture, but Ouch...

More money than I wanted to spend on that particular issue, but it's still cheaper than therapy, my ex-wife, narcotics, or gambling, plus these rigs are appreciating faster than real estate. I think that makes it a good investment overall!
Glad you got it sorted! I had to replace all my fuel lines as well. I was working on the fuel system and the old plastic fuel lines just started leaking after I moved them a little. Just way too old and brittle at this point. Worked out for the best because that is not a fun safety issue. I went with the Redline Cruisers kit. Pricey but very nice.
 

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