Onan 4KY fuel pump replacement method?
Does anyone have a step by step process to replace the fuel pump on an Onan 4KY? Upon testing my genny in the hot weather yesterday, it ran for about 10 minutes under load, then abruptly quit. ...
Forum Discussion
Fuel pump arrived yesterday - new part number: A029F889 drop-shipped from Cummins.
A friend dropped by so we decided to do the swapout.
The procedure (from memory - no pics this time)
1) Remove 12V lead from relay, insulate with tape, pull it out of the housing.
2) Unplug remote switch harness if desired. This helps when manipulating the harness later.
3) Remove two torx screws at front edge of frame to release control module bracket.
4) Remove cover over air filter.
5) Detach two control wires from relay, remove small lead from supply side of relay.
6) Lift and manipulate control module to gain access to connector on the bottom.
7) Using a small screwdriver, unlock and remove large connector from bottom of control module.
8) Manipulate and remove control module from compartment.
9) Remove white 12V lead from other side of relay, set control module aside
You are now able to deal with the pump....
10) Pinch off fuel supply line with vise grips at filter.
11) Loosen clamp, wear rubber/nitrile gloves, remove fuel line from filter. The barbs on filter is deep, so you'll need to be fairly agressive in removing the hose from the filter. Be prepared to get a little fuel...
12) Using a 1/2" socket, remove first nut from ground stud at lower left of the outside of the generator housing. This stud is tucked between the frame and base of the genny. (curse when you hit your head and draw blood when the nut turns loose)
13) Remove ground cable and star nut from stud.
14) Using a ratchet/socket on each side of the ground stud, one inside the housing and on the second nut at lower left of the outside of the generator housing, remove the second nut and star washer.
15) Remove the stud (which is a 5/16 bolt) from inside housing, complete with yet another star washer. Several ground wires will be on this bolt including the ground for the pump.
16) Remove ground from stud.
17) Unplug pump power lead.
18) Place a wadded up paper towel under the pump output nipple, then remove clamp and hose from outlet.
19) Remove 1 torx screw from left side of pump - this is the same size as the control module screws.
20) remove pump/filter assembly from housing; remove gas-soaked paper towel. You'll get more fuel from the outlet of the pump and the inlet of the filter as you remove it.
Finally! (Light up a cigarette and pop open a beer. You'll enjoy the fireworks...B^)
21) If you haven't replaced the filter recently, it's a good idea to put a new filter on the new pump. Use a bit of paste style pipe dope on the filter outlet, or use gas-proof yellow teflon tape. Install new filter on pump.
22) Install new pump/filter assembly in housing. Right side of bracket slides into a slot; install torx screw in left side.
23) Plug in the positive lead.
24) Add ground ring terminal to ground bolt, add star washer to bolt, insert in hole. Add star washer to stud outside of housing, install and tighten one nut.
25) Add third star washer to stud, install ground cable, add last nut, tighten.
26) Install fuel line to pump outlet.
27) Install white starter cable on outlet side of relay with nut & lockwasher; orient cable in the original direction.
28) Manipulate control module into housing, install large connector.
29) Control module has a foot that slides into a slot near the pump, you can feel the slot from the underside while installing the control module. Manage two cables that are routed under the module while positioning.
30) Install two torx screws at front edge of the housing to fasten control module bracket
31) Plug in remote switch harness.
32) Add ring terminal to relay input stud, plug in two control leads.
33) Route power lead, untape terminal, (keeping it away from metal objects!) install in input stud on relay with lockwasher and nut.
Unless I've missed a step, the installation is complete. I primed the setup by removing the fuel line at the carb and placing it in a suitable container, then pushed the switch the prime position. The pump was noisy for a couple seconds at first, then started pumping fuel. After reattaching the fuel line to the carb, I primed it for 10 seconds and tried starting it. No go, so a second prime session for 5 seconds, then it started.
While it was warming up, we checked for fuel leaks, then installed the outer cover. We ran the genny under the load of the AC for 35 minutes, it hiccuped once at about 15 minutes (uh oh..) when the AC compressor shut off the first time, but never died. After shutting down the AC, we shut 'er down and called it a successful task.
So now you know what's involved in replacing the fuel pump on an Onan KY.
--Bruce.
A friend dropped by so we decided to do the swapout.
The procedure (from memory - no pics this time)
1) Remove 12V lead from relay, insulate with tape, pull it out of the housing.
2) Unplug remote switch harness if desired. This helps when manipulating the harness later.
3) Remove two torx screws at front edge of frame to release control module bracket.
4) Remove cover over air filter.
5) Detach two control wires from relay, remove small lead from supply side of relay.
6) Lift and manipulate control module to gain access to connector on the bottom.
7) Using a small screwdriver, unlock and remove large connector from bottom of control module.
8) Manipulate and remove control module from compartment.
9) Remove white 12V lead from other side of relay, set control module aside
You are now able to deal with the pump....
10) Pinch off fuel supply line with vise grips at filter.
11) Loosen clamp, wear rubber/nitrile gloves, remove fuel line from filter. The barbs on filter is deep, so you'll need to be fairly agressive in removing the hose from the filter. Be prepared to get a little fuel...
12) Using a 1/2" socket, remove first nut from ground stud at lower left of the outside of the generator housing. This stud is tucked between the frame and base of the genny. (curse when you hit your head and draw blood when the nut turns loose)
13) Remove ground cable and star nut from stud.
14) Using a ratchet/socket on each side of the ground stud, one inside the housing and on the second nut at lower left of the outside of the generator housing, remove the second nut and star washer.
15) Remove the stud (which is a 5/16 bolt) from inside housing, complete with yet another star washer. Several ground wires will be on this bolt including the ground for the pump.
16) Remove ground from stud.
17) Unplug pump power lead.
18) Place a wadded up paper towel under the pump output nipple, then remove clamp and hose from outlet.
19) Remove 1 torx screw from left side of pump - this is the same size as the control module screws.
20) remove pump/filter assembly from housing; remove gas-soaked paper towel. You'll get more fuel from the outlet of the pump and the inlet of the filter as you remove it.
Finally! (Light up a cigarette and pop open a beer. You'll enjoy the fireworks...B^)
21) If you haven't replaced the filter recently, it's a good idea to put a new filter on the new pump. Use a bit of paste style pipe dope on the filter outlet, or use gas-proof yellow teflon tape. Install new filter on pump.
22) Install new pump/filter assembly in housing. Right side of bracket slides into a slot; install torx screw in left side.
23) Plug in the positive lead.
24) Add ground ring terminal to ground bolt, add star washer to bolt, insert in hole. Add star washer to stud outside of housing, install and tighten one nut.
25) Add third star washer to stud, install ground cable, add last nut, tighten.
26) Install fuel line to pump outlet.
27) Install white starter cable on outlet side of relay with nut & lockwasher; orient cable in the original direction.
28) Manipulate control module into housing, install large connector.
29) Control module has a foot that slides into a slot near the pump, you can feel the slot from the underside while installing the control module. Manage two cables that are routed under the module while positioning.
30) Install two torx screws at front edge of the housing to fasten control module bracket
31) Plug in remote switch harness.
32) Add ring terminal to relay input stud, plug in two control leads.
33) Route power lead, untape terminal, (keeping it away from metal objects!) install in input stud on relay with lockwasher and nut.
Unless I've missed a step, the installation is complete. I primed the setup by removing the fuel line at the carb and placing it in a suitable container, then pushed the switch the prime position. The pump was noisy for a couple seconds at first, then started pumping fuel. After reattaching the fuel line to the carb, I primed it for 10 seconds and tried starting it. No go, so a second prime session for 5 seconds, then it started.
While it was warming up, we checked for fuel leaks, then installed the outer cover. We ran the genny under the load of the AC for 35 minutes, it hiccuped once at about 15 minutes (uh oh..) when the AC compressor shut off the first time, but never died. After shutting down the AC, we shut 'er down and called it a successful task.
So now you know what's involved in replacing the fuel pump on an Onan KY.
--Bruce.
