Replacing The Fuel Pump: 1997 K2500 Edition

If you're looking to replace the fuel pump on your 1997 K2500, there are a few things you should know. Firstly, it's important to relieve fuel pressure from the engine before attempting any repairs. You will also need a variety of tools, including an air gun, line wrenches, a flathead screwdriver, sockets, and grease. When removing the fuel lines, be very careful as there will still be pressure behind them. Once you have access to the pump, loosen the retainer ring and use compressed air to remove any dirt. After cleaning the area, install the new pump, ensuring that all fittings are greased for a tight seal. Finally, reconnect the fuel lines and power the system to prime the pump.

Remove the fuel pump relay and depressurise the rail

To remove the fuel pump relay and depressurise the rail of your 1997 K2500, follow these steps:

First, pull the fuel pump relay. This will depressurise the rail. However, you will still have pressure from the regulator to the pump. Next, disconnect everything electrically. The bolt is a 13mm hex and the plug just unplugs. Loosen the small clamp on the small tube, then the large hose just needs to be loosened from the pump side.

Now, loosen the lines. They are both 3/4" hex on the engine side and 5/8" on the pump side. THE BIG LINE WILL HAVE PRESSURE BEHIND IT! Once it is loose, SLOWLY remove it or you'll take a shower of gas. Check to be sure the O-rings come out of the lines. Once those are done, loosen the retainer ring on the pump housing. Use compressed air to get dirt away from the hole. To pull the pump in one move, turn it so it will come out.

Clean the spot where the O-ring will sit. Slide the new O-ring into position on the new pump and just moisten it with petroleum jelly. Put the new pump in the same way. Put the new retainer ring on, then wet the top and bottom so that it will be easy to install. Tighten the pump into place. Next, use your petroleum jelly to wet the O-rings and fitting nuts, as well as the threads and tubing the nut slides over and pushes against. This will give you a nice tight seal. My pump came with O-rings on it and extras in a bag. Keep them. I think they fit at the fuel rail as well. Before you put the lines on, look down inside for bits of the old O-rings... You don't want that in your filter. Pick the bits out carefully if you must. I used a screwdriver. When you tighten the lines ONLY TURN THE NUT! Do not turn the engine side of the line as this will twist the O-ring around and may damage it!

Disconnect the electricals and loosen the clamp on the small tube

To disconnect the electricals and loosen the clamp on the small tube, you'll need a 13mm socket, a flathead screwdriver, and some needle nose pliers. First, remove the fuel pump relay to relieve the fuel pressure from the engine side. This will depressurise the rail, but you'll still have pressure coming from the regulator to the pump, so be cautious. Next, disconnect the electricals. The bolt is a 13mm hex, and the plug just unplugs. Now, loosen the small clamp on the small tube. You can then loosen the large hose on the pump side and move it out of the way.

Loosen the retainer ring on the pump housing

To loosen the retainer ring on the pump housing of your 1997 K2500, you will need to first relieve the fuel pressure from the engine side. This is important as it depressurises the rail. It is also recommended that you wear safety goggles or a face shield to protect your eyes from any spray of gas.

Once the pressure is relieved, you can begin to loosen the retainer ring. The retainer ring is a large threaded steel ring that screws onto a white plastic lip on the fuel tank. To loosen it, you will need to turn it counter-clockwise. You can use a screwdriver and hammer to tap it, working your way around in a circle, slowly rotating the ring free. You can also use a flat-head screwdriver and a hammer to tap the cut-outs and tabs on the retainer ring, going around in a circle and tapping each section to loosen the ring.

If the retainer ring is rusted, you can try to soak it with penetrating oil or PB Blaster to help loosen it. You can also try using a rubber strap wrench, channel lock pliers, or a serpentine belt and vise grips to loosen the ring. If you are having trouble breaking the rusted ring, you can try to cut or nip the tabs with wire cutters or bolt cutters and then use a flat-head screwdriver and hammer to tap and loosen the ring.

Once the retainer ring is loosened, use compressed air to blow away any dirt from the hole.

Clean the spot where the o-ring will sit and put the new one in place

To clean the spot where the o-ring will sit, you should first use compressed air to blow away any dirt or debris from the hole. Then, take your chosen lubricant and wet the top and bottom of the o-ring groove. This will ensure a tight seal and protect the plating on the tubes from galling. You can use petroleum jelly, silicone grease, or dielectric grease for this purpose. It is important to use a lubricant that is compatible with fuel systems, such as Buna-N, Viton Extreme, or Aflas TFE/P.

Once the groove is clean and lubricated, you can slide the new o-ring into position on the new fuel pump. It is recommended to moisten the o-ring with petroleum jelly or your chosen lubricant before placing it in the groove. This will help to create a tight seal and protect the components.

After the new o-ring is in place, you can put the new fuel pump into the tank. Make sure to tighten the pump securely and use lubricant on the o-rings, fitting nuts, threads, and tubing to ensure a proper seal and prevent damage during installation.

Finally, reconnect the fuel lines, ensuring that the O-rings are in place, and tighten the fittings. Be careful not to overtighten the fittings, as this can damage the O-rings. Once everything is connected, check for any leaks before starting the vehicle.

Tighten the pump and wet the o-rings and fitting nuts with petroleum jelly

To tighten the pump and wet the o-rings and fitting nuts with petroleum jelly, follow these steps:

First, ensure you have the correct type of o-ring for your fuel pump. Petroleum jelly can degrade certain o-rings over time, especially those made of rubber or buna. If you are unsure, consult a mechanic or automotive specialist.

Next, apply a small amount of petroleum jelly to the o-rings and fitting nuts with a clean cloth or cotton swab. Be careful not to apply too much, as excess jelly can attract dirt and debris.

Then, use a wrench to tighten the pump according to the manufacturer's specifications. Do not overtighten, as this can damage the pump and surrounding components.

Finally, reassemble the fuel pump according to the instructions for your specific vehicle. Ensure all connections are secure and there are no leaks before starting the engine.

It is important to note that petroleum jelly is not the only option for lubricating o-rings. Some mechanics recommend using silicone grease or food-grade lubricants, as they are less likely to degrade the rubber over time. Additionally, always exercise caution when working on fuel system components, as they can be dangerous if mishandled.

Frequently asked questions