02 Suburan 2500 Replaced Fuel Lines
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02 Suburan 2500 Replaced Fuel Lines
Hi all:
I have a 2002 Suburban 2500 with 4WD and the 8.1L engine with 170K miles.
It has dual tanks (front tank about 31gal, rear tank about 7 gal).
Earlier this year the main tank sending unit rusted out and caused a leak. I needed the Sub and it was winter, so I had a garage replace the pump/sender assembly (with an AC Delco unit).
I figured that the rear tank pump/sending unit was probably rusting out also, as were the fuel lines.
I ordered a replacement rear pump/sending unit (Delphi) from Rock Auto, along with a complete pre-bent fuel line kit.
The fuel line kit is made by a Canadian company, Fineline. The part# for the kit is FL149R (for my Suburban).
Selecting the correct rear tank pump/sending unit is tricky as there are 3 pumps to choose from. One is with a "robust" sending unit, which has a square-shaped connector with 2 rows of pins. Another pump has a long connector with 1 row of 4 pins (the one I have). Finally, the third pump is listed for Suburbans with an Evap system. This pump has two connectors, the extra connector is for a built-in pressure sensor to set the infamous "Evap system small or large leak" codes. The tricky part is that my Sub has an Evap system but not the pressure sensor. So for the purpose of selecting the right pump, my Sub doesn't have an Evap system, since it doesn't sense fuel system pressure for leaks, even though there is an Evap canister and plumbing.
The fuel line kit comes in several sections that join together with stainless braided hoses. This is the only way to go as it is apparent that GM puts the fuel lines in and then drops the body onto the frame. A single length could not be installed without lifting the body. These fuel lines have complex bends, folks! The fuel lines fit well, the only minor difference is that the stainless braided hoses are a little stiffer than the factory non-braided hoses, so its a little harder to make tight bends with them.
The new fuel lines snap into the factory brackets easily, as GM uses plastic brackets which do not rust.
Dropping the tanks is fairly easy, but you do need to disconnect the fuel lines and electrical connectors before dropping the tank all the way down. The fuel connections are quick-connect and come apart easily with the correct tool.
To remove the rear tank, you need to remove the spare tire and also a large steel H-bracket that is bolted to the frame. This H-bracket holds the spare tire lift assembly.
Just in case, our local auto parts store (Advance auto) sells a fuel tank strap kit, and also a strap bolt kit if needed.
I jacked up the rear of the Suburban, dropped the tanks, and replaced the rear sending unit/pump and the lines. It took about 14 hours total. There is one fuel line bracket that is attached to the bellhousing/engine bolt where it is real hard to reach. I was able to unscrew the nut and remove the bracket, but it would have been too hard to put the bracket back. Instead, I attached it somewhere nearby that was easier to reach.
The fuel filler is tee'd into the rear tank and also goes to the main tank. The rear tank pump transfers gas from the rear tank to the main tank as commanded by the control system. The dashboard fuel gauge reading is a combination of the fuel in the main tank and the fuel in the rear tank. The rear tank pump/sender has one nipple, for gas being pumped out to the main tank. The main tank pump/sender has 3 nipples, one for gas out to the engine, one for fuel returned from the engine, and one from the rear tank for fuel transfer. The main tank has one vent line, the rear tank has two vent lines. The three vent lines attach to the Evap canister which is mounted above the frame near the main tank. Finding information on how the system works is very hard. I have the factory service manuals for my Sub, but it shows very little about the fuel tanks and lines. After removing the system, I think I understand how most of it works.
Steve
I have a 2002 Suburban 2500 with 4WD and the 8.1L engine with 170K miles.
It has dual tanks (front tank about 31gal, rear tank about 7 gal).
Earlier this year the main tank sending unit rusted out and caused a leak. I needed the Sub and it was winter, so I had a garage replace the pump/sender assembly (with an AC Delco unit).
I figured that the rear tank pump/sending unit was probably rusting out also, as were the fuel lines.
I ordered a replacement rear pump/sending unit (Delphi) from Rock Auto, along with a complete pre-bent fuel line kit.
The fuel line kit is made by a Canadian company, Fineline. The part# for the kit is FL149R (for my Suburban).
Selecting the correct rear tank pump/sending unit is tricky as there are 3 pumps to choose from. One is with a "robust" sending unit, which has a square-shaped connector with 2 rows of pins. Another pump has a long connector with 1 row of 4 pins (the one I have). Finally, the third pump is listed for Suburbans with an Evap system. This pump has two connectors, the extra connector is for a built-in pressure sensor to set the infamous "Evap system small or large leak" codes. The tricky part is that my Sub has an Evap system but not the pressure sensor. So for the purpose of selecting the right pump, my Sub doesn't have an Evap system, since it doesn't sense fuel system pressure for leaks, even though there is an Evap canister and plumbing.
The fuel line kit comes in several sections that join together with stainless braided hoses. This is the only way to go as it is apparent that GM puts the fuel lines in and then drops the body onto the frame. A single length could not be installed without lifting the body. These fuel lines have complex bends, folks! The fuel lines fit well, the only minor difference is that the stainless braided hoses are a little stiffer than the factory non-braided hoses, so its a little harder to make tight bends with them.
The new fuel lines snap into the factory brackets easily, as GM uses plastic brackets which do not rust.
Dropping the tanks is fairly easy, but you do need to disconnect the fuel lines and electrical connectors before dropping the tank all the way down. The fuel connections are quick-connect and come apart easily with the correct tool.
To remove the rear tank, you need to remove the spare tire and also a large steel H-bracket that is bolted to the frame. This H-bracket holds the spare tire lift assembly.
Just in case, our local auto parts store (Advance auto) sells a fuel tank strap kit, and also a strap bolt kit if needed.
I jacked up the rear of the Suburban, dropped the tanks, and replaced the rear sending unit/pump and the lines. It took about 14 hours total. There is one fuel line bracket that is attached to the bellhousing/engine bolt where it is real hard to reach. I was able to unscrew the nut and remove the bracket, but it would have been too hard to put the bracket back. Instead, I attached it somewhere nearby that was easier to reach.
The fuel filler is tee'd into the rear tank and also goes to the main tank. The rear tank pump transfers gas from the rear tank to the main tank as commanded by the control system. The dashboard fuel gauge reading is a combination of the fuel in the main tank and the fuel in the rear tank. The rear tank pump/sender has one nipple, for gas being pumped out to the main tank. The main tank pump/sender has 3 nipples, one for gas out to the engine, one for fuel returned from the engine, and one from the rear tank for fuel transfer. The main tank has one vent line, the rear tank has two vent lines. The three vent lines attach to the Evap canister which is mounted above the frame near the main tank. Finding information on how the system works is very hard. I have the factory service manuals for my Sub, but it shows very little about the fuel tanks and lines. After removing the system, I think I understand how most of it works.
Steve
