Changing The Fuel Cell On Your 3126 Cat: A Step-By-Step Guide

how to change fuel cell on 3126 cat

Changing the fuel filter on a 3126 Cat engine can be a tricky process. The engine needs at least 25 psi to start, so if the pressure is low, the injectors won't fill up with fuel, leading to starting issues. If you're experiencing problems with your 3126 Cat, it's recommended to check the fuel pressure and, if necessary, change the fuel filters. It's also important to ensure that the filters are filled before installation, as trying to start the engine with dry filters can lead to issues. Additionally, some 3126 Cat engines have a hand priming pump, which can be used to build up pressure and help with starting the engine.

Characteristics Values
Fuel filter type 2 micron
Fuel filter location With the fuel/water separator
Fuel filter replacement frequency Every 11,000 miles
Fuel filter replacement procedure Install dry, run the starter for 30 seconds, let the starter cool for two minutes and try again
Fuel filter pre-filling procedure Plug the center hole, pour fuel in the outer holes
Fuel filter pre-filling necessity Not required if there is a primer pump
Fuel filter pre-filling necessity Required if there is no primer pump
Fuel filter pre-filling necessity Recommended by some mechanics

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Prefilling the filter

Firstly, it is recommended to use a clean fuel source to prefill the filter. This can be done by using filtered fuel from a pump at a gas station or, in the absence of diesel fuel, using transmission fluid or kerosene. These alternatives are known to be clean and easily accessible.

When you are ready to prefill the filter, start by identifying the different holes on the top of the filter. There will be a large hole in the centre, which is the fuel flow to the engine, and smaller holes around the outer ring. The fuel flow through the filter goes from the outer holes to the centre.

To prefill the filter, block the centre hole and pour the clean fuel through the outer holes. Ensure that the filter is completely filled, and there is no air left in the system. Air in the system can cause significant starting problems for your engine.

Once the filter is filled, you can screw it into place. Some people recommend removing the water separator and fuel filter as a unit and then separating them. This can be done by unscrewing the water separator from the bottom of the filter. Remember to drain the filter before removing it.

By following these steps and ensuring that your filter is completely filled with clean fuel, you will help ensure a smooth and successful fuel filter change on your 3126 CAT engine.

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Bleeding the system

Bleeding the fuel system of a 3126 CAT engine involves removing air from the fuel lines and ensuring that fuel can flow smoothly. Here is a step-by-step guide on how to do it:

Step 1: Prepare the necessary tools and materials

You will need a hand primer pump, a fuel filter, and some diesel fuel. The hand primer pump should be similar to the one found here: http://www.ebay.co.uk/itm/LASER-3813-Diesel-Fuel-Pump-Priming-Tool-/130765661258. It is also recommended to have an assistant to help with cranking the engine.

Step 2: Connect the hand primer pump

Fit the hand primer pump to the outlet of the fuel filter. You may need to remove the fuel line that runs from the back of the head to the housing to make this step easier.

Step 3: Prime the fuel system

Pump the hand primer until diesel fuel comes through. Once diesel starts flowing, leave the pump connected to the filter.

Step 4: Connect the hand primer pump inline

Connect the other end of the hand primer pump to the pipe from the filter to the pump so that the hand primer is inline.

Step 5: Crank the engine and continue pumping

While your assistant cranks the engine, continue pumping the primer to force fuel into the fuel pump.

Step 6: Let the engine idle

Once the engine starts, let it idle for a few minutes, then switch it off and remove the priming pump.

Additional Tips:

  • It is recommended to not just crank the engine to bleed the fuel system, as this can cause a flat battery and damage the fuel pump due to the pump turning without diesel in it.
  • Ensure that you have at least 25 psi of fuel pressure to start the engine. If the pressure is low, change the fuel filters.
  • If the pressure is still low after changing the filters, suspect a failed fuel pressure regulator on the back of the head or a weak fuel transfer pump.
  • Make sure that the shut-off lever is in the run position on the pump.
  • If you are having trouble getting fuel to come out of the loosened fittings, try turning the engine to a different spot on the cam.
  • When filling a new filter, use a rubber stopper that fits the large hole in the fuel filter and pour the fuel through the small holes. This ensures that the fuel flows in the same path as it would when the filter is in use.
When to Replace Your Fass Fuel Filters

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Removing the fuel/water separator bowl

To remove the fuel/water separator bowl, you will first need to locate the fuel/water separator. This is usually found below the fuel filter.

Once you have located the fuel/water separator, you will need to remove it from the fuel filter. This can be done by unscrewing it from the bottom of the filter. Be sure to have a container or rag handy to catch any fuel or water that may spill out.

After the fuel/water separator has been removed, you will need to drain any remaining fuel and water from it. This can be done by pouring the contents into a container or rag. Be sure to dispose of the fuel and water properly.

Now, you will need to clean the fuel/water separator. This can be done by rinsing it out with fresh fuel or transmission fluid. Be sure to dry it thoroughly before reinstalling it.

Finally, you can reinstall the fuel/water separator onto the fuel filter. Be sure to screw it on tightly to prevent any leaks.

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Cracking the injectors

Injectors are typically found on top of the cylinder head, secured with retaining nuts or bolts. Before you begin, ensure you have the right tools for the job: a socket wrench set with appropriate sockets, an injector puller tool, and safety goggles and gloves. Park your vehicle in a well-ventilated area and engage the parking brake. Open the hood and ensure the engine is cool to the touch.

To remove the injectors, first disconnect the negative terminal of the battery to prevent accidental electrical contact and reduce the risk of injury. Next, remove the fuel lines connected to each injector using the appropriate wrench or socket, being careful not to damage the fuel lines or fittings. Place a clean rag over the open ends of the fuel lines to prevent contamination.

Now it's time to "crack" the injectors. This involves unthreading the end of the injector line at the top of the injector—only a few threads need to be unthreaded. With 3 or 4 lines cracked, turn over the engine for about 5 to 10 seconds with the accelerator fully depressed. If your fuel injection system is working properly, diesel fuel should dribble out of the lines immediately. If nothing comes out, there is air in the injection pump (IP) and/or lines.

To purge the air manually, crank the engine for no longer than 15 seconds. Let the starter rest for 2 minutes, and then repeat the 15-second cranking process. Keep doing this until you see diesel creeping out of the top of the injectors. Wipe the dribbling fuel with a paper towel, and once the spurting fuel is consistent, use the 5/8″ wrench to tighten the end of the injector line on the injector. Do this one-by-one for each injector.

After you've tightened down the lines, the engine will start to sputter and may even start. Give the engine half throttle to work out any remaining bubbles. As soon as possible, torque down the remaining injectors. If you delay, diesel fuel will spray all over the engine bay. There may be a few minutes of rough idling as the remaining bubbles work their way through the injectors.

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Checking the engine manual

The manual will also outline any special tools or equipment that may be required for the job, such as an oil filter wrench or a specific type of fluid to fill the new filter. Additionally, the manual will provide step-by-step instructions on how to access the fuel filter, remove the old one, and install the new one properly. This can be especially helpful if you are working in a tight space, as the manual may suggest tips or tricks to make the job easier.

Furthermore, the engine manual will specify the recommended maintenance schedule for the fuel filter, including how often it should be inspected, cleaned, or replaced. This can help you stay on top of fuel filter maintenance and avoid unexpected issues on the road.

In addition to the above, the manual may also include troubleshooting information to help diagnose and resolve any problems that may arise during the fuel filter replacement process. This can be extremely valuable if you encounter any unexpected challenges during the job.

Finally, the engine manual may also include important safety information and precautions to be aware of when working on the Cat 3126 engine. This can help ensure that you are taking the necessary steps to protect yourself and your vehicle during the maintenance or repair process.

By consulting the engine manual, you can ensure that you are following the manufacturer's recommendations for fuel filter replacement and maintaining your Cat 3126 engine properly.

Frequently asked questions

You will need a new fuel filter, a wrench, and some rags. First, locate the fuel filter. It is usually found near the fuel tank. Once you have located it, use the wrench to loosen the filter and remove it. Be careful not to spill any fuel. Install the new fuel filter by hand-tightening it first and then giving it an extra quarter-turn with the wrench. Make sure the filter is secure and wipe up any spilled fuel with a rag.

There are a few ways to prime the fuel filter on a 3126 CAT engine. One way is to use a hand priming pump if your engine has one. Simply pump it until it becomes firm, and you have removed all the air from the fuel system. Another way is to fill the new fuel filter with fuel before installing it. To do this, plug the center hole of the filter and pour fuel into the smaller outer holes. Then, remove the plug from the center hole and install the filled filter. Start the engine and let it idle for a few minutes.

Some common issues with the fuel system on a 3126 CAT engine include a low or no fuel pressure condition, a low injection actuation pressure, and a faulty engine speed timing sensor. If you are experiencing starting issues, check the fuel pressure, injection actuation pressure, and engine speed timing sensors.

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