Mechanical fuel pump tank return bypass?

[nabeshin]

Tried to do a bit of search here but didn't come up with much.

I noticed my fuel pump is leaking; squirts of fuel out the back end of the flying saucer part at the seam towards the manifold. I was checking to see if I had fixed an exhaust leak after tightening the manifold down pipe nuts when I saw this.

Exhaust is fine now, but I need a new pump. It was replaced at some point, it is not original, but seems to be an AC Delco unit. It has two outputs, one to carb, and one to return to tank. Summit is a little light on replacements with a return, can i cap the return and just use a pump with one outlet to the carb?

 

[Termite_Delight]

I bought mine from Amazon

https://www.amazon.ca/ACDelco-41216...automotive&vehicleId=1&vehicleType=automotive

 

[nabeshin]

Summit is my go-to, didn't really think to check Amazon for car parts. Thanks.

 

[Snoots]

Tried to do a bit of search here but didn't come up with much.

I noticed my fuel pump is leaking; squirts of fuel out the back end of the flying saucer part at the seam towards the manifold. I was checking to see if I had fixed an exhaust leak after tightening the manifold down pipe nuts when I saw this.

Exhaust is fine now, but I need a new pump. It was replaced at some point, it is not original, but seems to be an AC Delco unit. It has two outputs, one to carb, and one to return to tank. Summit is a little light on replacements with a return, can i cap the return and just use a pump with one outlet to the carb?

No. You should not cap the return line.

 

[nabeshin]

Thanks for the input. I'll look around on Amazon and just hope I don't get a counterfeit one.

 

[gotyourgoat]

You are not seeking the unobtainable. Any parts store will sell you a mechanical fuel pump for a small block Chevy. And if summit is out, there's always rockauto or jcwhitney or jegs or Ebay or a thousand other places.

Or there's one in the bed of my truck I bent up with a cheater bar trying to force a damaged flair fitting to seal. You can have that one for free.

 

[1987 GMC Jimmy]

No. You should not cap the return line.

I couldn't agree more. My car was made literally weeks before they started putting return lines on them, and it will not fail to vapor lock after a hot soak with ambient temps of >80*F. If I knew what I know now back then, I would have gone with the three line sender, ran a braided line, and gone with a return style pump. I don’t know how much it helps, but it’s better than nothing.

 

[eskimomann209]

I bought mine from Amazon

https://www.amazon.ca/ACDelco-41216-Original-Equipment-Mechanical/dp/B000C9MGCE/ref=au_as_r?_encoding=UTF8&Make=GMC|48&Model=K25|532&Year=1976|1976&ie=UTF8&n=6948389011&s=automotive&vehicleId=1&vehicleType=automotive

What the frick Canadian eh?

 

[Craig 85]

Rockauto is a good source for part numbers. Prices are usually good, but shipping can be the killer at times.

https://www.rockauto.com/en/catalog...l+400cid+v8,1307966,fuel+&+air,fuel+pump,6256

 

[SirRobyn0]

Get a pump with a return line. The main purpose to that line is to keep the fuel in the line before the pump moving, this reduced vapor locking. Trust me it really does make a difference.

 

[75gmck25]

I bought a new 3 fitting fuel pump for my truck last year and was able to find it in stock at Autozone. Its not a Delco, but for a part that cheap and easy to replace I'm not concerned with using a store brand part.

Bruce

 

[Donald]

I installed a blazer tank on my c15 and capped the return line at the pump a year ago and it works great .

 

[nabeshin]

Got one from Napa and it's installed, doesn't leak and seems to keep the truck running.

https://www.gmsquarebody.com/threads/fly-over-country-farm-truck.28240/page-2

 

[Matt69olds]

The other advantage of the return line is to drop fuel pressure at the carb once the engine shuts down. After a hot soak, fuel trapped in the fuel line between the pump and the carb can begin to boil, raising the fuel pressure high enough to push fuel past the needle and seat and flooding the engine. The return line fitting in the pump has a small orifice that bleeds off fuel back to the tank. As stated before, the constant fuel circulating help kept the pump and fuel coil.