84 k10 squaer body mechanical fuel pump

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Shadetree755

Junior Member
Joined
Jul 3, 2026
Posts
1
Reaction score
0
Location
FL
First Name
david
Truck Year
1984
Truck Model
k10
Engine Size
350
had a mechanical fuel pump installed for 60,000 miles. it started leaking at the diaphram holes. old pump had the visible external spring under the fuel pump arm. purchased a Delphi mf0002 (wich fits the truck) it did not have the visible external pump arm spring the auto parts said it was internal. it lasted about 30 miles and when i removed the pump the arm had no spring tension just flopped around. anybody else seen this issue with these internal spring pumps. thanks
 

Terlingueno

Full Access Member
Joined
Dec 29, 2020
Posts
517
Reaction score
1,865
Location
Far West Texas
First Name
Skeeter
Truck Year
1985
Truck Model
K20 Suburban
Engine Size
350/SM465
The pump that is currently on my K20 with a 350 is an ACDelco made in MX. It is just like all four of the pumps I have in the vault, AC, two ACDelco's (one US made, one MX made) and a Carter. In the pics, the only spring is in the housing above the diaphram which I marked with a black line. I have only had three fuel pumps fail in the 32 years I have owned it, each about 10 years apart mas o menos, and all have been AC or AC Delco. I have seen the pumps with angled spring, but not used one. On Rock Auto, the Spectra appears to not have the angled spring, the others do.

You must be registered for see images attach
You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach
 

PrairieDrifter

Full Access Member
Joined
Dec 28, 2014
Posts
4,775
Reaction score
8,193
Location
North Dakota
First Name
Mason
Truck Year
84,79,77,76,70,48
Truck Model
Suburban k10, bonanza k10, k30, k20, c10, gmc 1/2ton
Engine Size
350, 350, 350, 350, 350, 350
had a mechanical fuel pump installed for 60,000 miles. it started leaking at the diaphram holes. old pump had the visible external spring under the fuel pump arm. purchased a Delphi mf0002 (wich fits the truck) it did not have the visible external pump arm spring the auto parts said it was internal. it lasted about 30 miles and when i removed the pump the arm had no spring tension just flopped around. anybody else seen this issue with these internal spring pumps. thanks
Parts store pumps are garbage. I've had 6 fail, most in very short time, ended up taking out the cam lobe too. Need aftermarket or NOS delco pumps.

I spent the extra cash on an Edelbrock mechanical for another truck, and it's supposed to be made in USA and seemed to work good. Have to modify the fuel line a little bit. Does also have a leak vent to outside. I did sell the truck not long after though.

My Holley red electric pump was loud and garbage. I like my Edelbrock carb rated electric pump from oreillys. I've gotten wayyyyy more miles out of that one and it's really quiet. Both electrics were/are mounted in the optimal location.
 

Latest posts

Forum statistics

Threads
48,758
Posts
1,076,569
Members
43,518
Latest member
1980gmc
Top