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Check with the engine manufacturer for the recommended micron rating. Your engine make, model and year determine what filter is needed.

Refer the Filter Selection webpage to select the correct part number.

A torque limiting vent cap is now standard for DAVCO Fuel Processors. A wrench is not needed to remove the vent cap and the torque limiting features prevents overtightening.

You can purchase DAVCO collar wrenches through our online store.

Diesel Pro 230, 232, 233, 234, 242, 243, Shop Pro ST

  • OD Collar: 5 inches
  • Metal: P/N 232007DAV
  • Composite: P/N 232002
  • Heavy Duty wrench: 243030DAV

Fuel Pro 380, 382, 384

  • OD Collar: 6"
  • Metal wrench: P/N 380134DAV
  • Heavy Duty Wrench: P/N 382152DAV

Fuel Pro 482, 483, 485, 487 and 488 as wellShop Pro FXP

  • OD Collar: 8"
  • Metal wrench: P/N 482017
  • Heavy duty wrench: P/N 488001DAV

A standard Filter Element will fit all Fuel Pro 382s and Diesel Pro 243s – The “Plus Size” filter element will only fit the “Plus Size” cover, which is standard on all 382, 383 and 384 units after 2008.

Visit this page for WIF information. Click on the thumbnail photos for a larger view of the WIFS.

Visit this page for Electric Pre-Heater information. Click on the thumbnail photos for a larger view of the Heaters.

After filling the top of the clear cover, start the engine and allow it to run for several minutes. Open the vent cap to release the vacuum, then tighten the vent cap. The fuel level may rise momentarily when the engine is started, but will drop after that. If the fuel level rises to the black band on the filter wrap and does not fall, the filter should be changed.

It’s not uncommon that the fuel level is at or below the collar when new filter is installed. As contaminants build up in the filter, the fuel level will rise. If there is a power complaint and the fuel is below the cover, check for a missing grommet on the stud and that the vent cap is securely closed. Do not use a tool to tighten the vent cap, as this may distort the o-ring and cause an air leak.
There are two types of bubbles. Vapor bubbles are caused by vibration and fuel passing though the fuel system. They will appear and be reabsorbed by the fuel. Vapor bubbles are tiny “champagne sized”. Vapor bubbles do not cause performance issues and will not be present after the lift pump.

Refer to Form F1318 to determine whether the bubbles are air or vapor bubbles.

If they are air bubbles, refer to F3089 to determine the sou

rce of the air leak.

Not necessarily, generally the check valve is for filter change only. The vacuum in the clear cover holds the fuel in place so odds are that there is a leak on the suction side of the system between the Fuel Pro and the Fuel pump.
With the engine shut off, open the vent cap on top of the clear cover. If the fuel level stays where it is at then the check valve is operating correctly. If the fuel level drops, the check valve needs to be serviced.
Ask your shop supervisor or fleet manager if there is a policy already in place, if there is no set policy it is recommended that the Fuel Processor be drained when the equipment is being refueled. The amount of water in the fuel may vary depending on the source of the fuel and the ambient temperature. A WIF (Water in fuel sensor) is available to assist in determining when the to drain the water from the Fuel Processor.
This highly dependent on the equipment the Fuel Processor is being installed on. In general:
  1. The Fuel Processor should be mounted so the clear cover is higher than the fuel tank.
  2. Install the Fuel Processor on the vacuum side of the fuel system.
  3. Keep hoses away from hot engine components (turbo and exhaust components). Do not allow fuel hoses to become pinched or droop excessively. Industrial Pro fuel processors should not be mounted directly on the engine.
Add fittings to connect a 3/8” NPTF to a 5/8” hose barb in the coolant heater ports on the bottom of the Fuel Pro. Ensure that the existing coolant lines do not go through the heater core. Otherwise, unless the fuel in the Fuel Processor is cold enough to require heat, the cab heater will not work. Hoses that cause fuel to flow through the heater core will need to be relocated.
The diverter caps sizes vary from truck to truck and engine to engine. Determine what your filter dimensions are by looking up which filter you have using the on-line catalog at or then use the cross ref chart in the installation instruction to find which Diverter Cap to use.
The “Y” cord is a standard connection simply line up the prongs, press the boot into heater and tighten the locking ring.
The black button is the pressure relief valve that allows for maximum filter life. This is part of the EleMax technology that extends of the life of the filter.Refer to the page about the Elemax filter for more information.
This is the filter wrap. Do not remove it. In combination with the pressure relief valve, the wrap maintains the differential pressure between the outside of the filter and the inside of the filter. Fuel continues to be filtered inside of the wrap. Even though the filter media may appear very dark, the filter does not need to be changed until level reaches the black band printed on the wrap.

Refer to the page about the Elemax filter for more information.

This can be done at all major US On-highway OEM dealers.

Refer to the OEM Codes for the code for engine model and options.

First, Determine the exact part number for the unit that is installed on your equipment(or this use the Product Identification Page) to compare models and features. If the product is still in production it will be a one-for-one swap, otherwise, a newer model will need to be substituted. Do not return the unit to DAVCO unless you obtain a Return Goods Authorization first.

Refer to this page for return instructions.

Prior to 2001 the emergency stud was matched to the engine, for example if you have a Detroit engine the emergency stud would be 13/16”-12 which is the same as a Detroit secondary fuel filter. During 2001 some OEM’s started standardizing to 1”-14 for the emergency stud. DAVCO also color-coded the studs the most common are the “Silver” 1”-14 stud and the “Gold” 13/16” 12 stud.

 Download form F1315 (pdf).

Service parts are available at most shops that service trucks. For links to OEM dealers, refer to this page.

Refer to the Service Parts page for part numbers.

All Fuel Pro and Diesel Pro models are leak checked before leaving the factory. If you believe there is a leak, leak testing the Fuel Processor is not difficult but some care needs to be taken not to damage any parts. Drain the Fuel Processor completely into an approved container. Remove the fuel lines at the inlet and outlet ports. Plug the outlet port with a 1/2" NPTF plug and install an air hose quick disconnect fitting in the fuel inlet port. It is important that the unit not be over pressurized as damage and/or injury could occur. Reduce the air pressure on the air hose to 30 psi (max.) and connect the air hose to the quick disconnect fitting in the inlet. Spray the Fuel Processor with soapy water from a spray bottle and check for bubbles. Refer to information on this page for Diagnostics instructions.