Fuel Pumps

Fuel Pumps for Lycoming® Engines

Tempest® has the most extensive offering of FAA approved new and overhauled Lycoming diaphragm fuel pumps available anywhere. Our new pumps use a cast housing and channel arm design.  All overhauled fuel pumps internal parts are replaced with new certified parts.  The actuating arms are magnetic particle test inspected; cast parts are inspected for wear, corrsion and cracks.  We overhaul both the older laminated and newer channel style fuel pumps for normally aspirated, pressure carburetor and fuel injected systems.

Information contained in this application data is for reference only. Although great effort has been made to ensure accuracy and completeness, Aero Accessories/Tempest® assumes no responsibility for the information contained within this document. Responsibility for airworthiness of aircraft, including the installation of correctly selected approved replacement of parts lies with the aircraft owner/operator per FAR 91.163, FAR 121.363, FAR 123.45, FAR 127.131 and FAR 135.143 (a). Please refer to FAA or engine/airframe/propeller manufacturers’ parts listing for approved part numbers for each application.  Tempest brand products are manufactured by Aero Accessories, LLC.

The Early Model Lycoming Fuel Pump (40174/40295 low pressure, 40595 medium pressure, 40296 high pressure) In the spring of 1964, AC introduced the first dual diaphragm type fuel pumps. These pumps were the first models to incorporate the oil seal integrated with the upper diaphragm and a separator ring for installation of the vent / overboard drain line. These pumps are characterized by a rocker arm which is an early riveted, laminated design. Current production in Lycoming pumps will not fit some pre-1978 applications without expensive modifications. You can eliminate the need for these modifications by ordering an FAA Approved overhauled early model pump for direct replacement. The Late Model Lycoming Fuel Pump During August of 1978, AC introduced what is now known as the “late model” fuel pump which has a “channeled” rocker arm. This pump is taller than the early laminated arm pump and has a unitized diaphragm assembly. Because of its increased size some pre-1978 model aircraft require expensive and time consuming modifications to carburetors or accessory housings (ref: Lycoming Service Inst. No. 1110C). These modifications are not required if our smaller, early model laminated fuel pumps are installed on your aircraft.

Q: Is there a mandatory replacement time for diaphragm fuel pumps?
A: Diaphragm fuel pumps should be replaced or overhauled:
1. At engine TBO or after ten years in service, whichever occurs first. Replace on condition if leaks develop or performance drops for example.
​​2. Refer to ​Lycoming Mandatory Service Bulletin 240W ​for information regarding engine TBO.

Q: Which Fuel Pump is correct for installation on my aircraft?
A: Please refer to the application charts on the fuel pump page to find the correct pump for your aircraft. If you or your mechanic will supply us with the aircraft make, model and engine type, we will be happy to provide you with the applicable pump for your aircraft (call 1-800-822-3200 or e-mail gehrlich@aeroaccessories.com).

Q: I have just installed my new Fuel Pump and my engine will not start. Why?
A: A common cause for this problem is fuel starvation due to improper installation of the fuel pump. Make sure that the fuel lines are not crossed; that is, the inlet line should be connected to the inlet side of the pump (marked “IN” on the top of the port) and the outlet line should be attached to the fuel pump outlet port. Fuel should be present at the inlet side of the fuel pump.

Improper installation of the fuel pump may result in a misalignment of the operating lever with the operating plunger in the accessory case. If so, there will be no movement of the lever and no pumping motion to provide fuel flow. If misalignment is found upon removal of the pump, the lever is probably damaged or broken. If misalignment of the operating lever has occurred, it will require inspection and repair by a qualified technician. If you would like to have Tempest/Aero Accessories Inc. perform repairs on a broken or misaligned lever, please contact us at 1-800-822-3200, Mon.-Fri., 8am-5pm Eastern Standard time, or e-mail us at gehrlich@aeroaccessories.com.

Q: What is causing the fuel (or oil) to leak from my Fuel Pump drain line?
A: Leakage of fuel or oil through the fuel pump overboard drain line indicates a worn or ruptured diaphragm inside the fuel pump. The fuel pump should be replaced before further flight

Q: What is causing my fuel pressure to fall below the “green arc”?
A: The most common reasons for low fuel flow/pressure are the following:
1. A worn or broken O-ring on the inlet side fuel fitting can cause an inlet suction leak. An inlet air leak will result in low Fuel Pump output pressure.
2. A weak operating spring in the Fuel Pump diaphragm assembly;
3. A worn fuel pressure gauge;
4. A clogged fuel vent or fuel cap;
5. A constriction in a fuel line either externally (a kinked hose), or internally (due to a collapsed hose lining).
6. Wrong fuel pump for the installation.

Q: What is causing my fuel pressure to fluctuate?
A: Fluctuating fuel pressure can be the result of the following:
1. A worn fuel pressure gauge;
2. A worn or broken O-ring on the inlet side fuel fitting;
3. A defective fuel selector valve (boost pump may labor);
4. An obstruction in the induction system (air intake);
5. A clogged or dirty fuel strainer;
6. Foreign material inside the fuel body (such as fuel cell sealant, thread sealant, or a drill shaving).

Fuel Pumps for RAJAY® Equipped Engines

RAJAY fuel pumps are modifed versions of the standard AC/Lycoming® types used on specific aircraft equipped with RAJAY turbochargers. The modifications include an upper deck reference port and a slightly stronger diaphragm spring to increase the fuel pressure for the turbocharger at a higher altitude.

Information contained in this application data is for reference only. Although great effort has been made to ensure accuracy and completeness, Aero Accessories/Tempest® assumes no responsibility for the information contained within this document. Responsibility for airworthiness of aircraft, including the installation of correctly selected approved replacement of parts lies with the aircraft owner/operator per FAR 91.163, FAR 121.363, FAR 123.45, FAR 127.131 and FAR 135.143 (a). Please refer to FAA or engine/airframe/propeller manufacturers’ parts listing for approved part numbers for each application.  Tempest brand products are manufactured by Aero Accessories, LLC.

The RAJAY Fuel Pump In the 1970’s, RAJAY Corporation, Inc. acquired several STC’s for turbo normalizing installations on certain aircraft. These pumps are distinguished from standard AC/Lycoming® fuel pumps by the presence of an upper deck reference port modification on the pump body. Tempest®/Aero Accessories, LLC has developed an FAA Approved overhaul process to support a limited number of the RAJAY models.

Q: Is there a mandatory replacement time for diaphragm fuel pumps?
A: Diaphragm fuel pumps should be replaced or overhauled:
1. At engine TBO or after ten years in service, whichever occurs first. Replace on condition if leaks develop or performance drops for example.
​​2. Refer to ​Lycoming® Mandatory Service Bulletin 240W ​for information regarding engine TBO.

Q: Which Fuel Pump is correct for installation on my aircraft?
A: Please refer to the application charts on the fuel pump page to find the correct pump for your aircraft. If you or your mechanic will supply us with the aircraft make, model and engine type, we will be happy to provide you with the applicable pump for your aircraft (call 1-800-822-3200 or e-mail gehrlich@aeroaccessories.com).

Q: I have just installed my new Fuel Pump and my engine will not start. Why?
A: A common cause for this problem is fuel starvation due to improper installation of the fuel pump. Make sure that the fuel lines are not crossed; that is, the inlet line should be connected to the inlet side of the pump (marked “IN” on the top of the port) and the outlet line should be attached to the fuel pump outlet port. Fuel should be present at the inlet side of the fuel pump.

Improper installation of the fuel pump may result in a misalignment of the operating lever with the operating plunger in the accessory case. If so, there will be no movement of the lever and no pumping motion to provide fuel flow. If misalignment is found upon removal of the pump, the lever is probably damaged or broken. If misalignment of the operating lever has occurred, it will require inspection and repair by a qualified technician. If you would like to have Tempest®/Aero Accessories Inc. perform repairs on a broken or misaligned lever, please contact us at 1-800-822-3200, Mon.-Fri., 8am-5pm Eastern Standard time, or e-mail us at gehrlich@aeroaccessories.com.

Q: What is causing the fuel (or oil) to leak from my Fuel Pump drain line?
A: Leakage of fuel or oil through the fuel pump overboard drain line indicates a worn or ruptured diaphragm inside the fuel pump. The fuel pump should be replaced before further flight

Q: What is causing my fuel pressure to fall below the “green arc”?
A: The most common reasons for low fuel flow/pressure are the following:
1. A worn or broken O-ring on the inlet side fuel fitting can cause an inlet suction leak. An inlet air leak will result in low Fuel Pump output pressure.
2. A weak operating spring in the Fuel Pump diaphragm assembly;
3. A worn fuel pressure gauge;
4. A clogged fuel vent or fuel cap;
5. A constriction in a fuel line either externally (a kinked hose), or internally (due to a collapsed hose lining).
6. Wrong fuel pump for the installation.

Q: What is causing my fuel pressure to fluctuate?
A: Fluctuating fuel pressure can be the result of the following:
1. A worn fuel pressure gauge;
2. A worn or broken O-ring on the inlet side fuel fitting;
3. A defective fuel selector valve (boost pump may labor);
4. An obstruction in the induction system (air intake);
5. A clogged or dirty fuel strainer;
6. Foreign material inside the fuel body (such as fuel cell sealant, thread sealant, or a drill shaving).

Fuel Pumps for Continental® Engines

Original equipment fuel pumps for early Continental engines, and airplanes such as the Ercoupe or Globe Swift were once extremely hard to find and their price reflected it. Tempest® Iistened to you, our customers, and now offers the most popular models at an affordable price. Choose from FAA-PMA factory new models or our FAA Approved overhauled models.

*Uses camshaft P/N 626608 or supersedure to which P/N 630403 or supersedure Gear and Eccentric has been assembled. REFERENCE CONTINENTAL SERVICE BULLETIN M-76-15 **See aircraft and engine manual; this engine may use either AC part numbers 9867 or 9076, TCM part numbers 40585 or 40695 – Aero Accessories part numbers AF-40585 or AF-40695.

Information contained in this application data is for reference only. Although great effort has been made to ensure accuracy and completeness, Aero Accessories/Tempest® assumes no responsibility for the information contained within this document. Responsibility for airworthiness of aircraft, including the installation of correctly selected approved replacement of parts lies with the aircraft owner/operator per FAR 91.163, FAR 121.363, FAR 123.45, FAR 127.131 and FAR 135.143 (a). Please refer to FAA or engine/airframe/propeller manufacturers’ parts listing for approved part numbers for each application.  Tempest brand products are manufactured by Aero Accessories, LLC.

New Tempest® (Continental) Fuel Pump  We offer a complete line of FAA-PMA approved factory new fuel pumps for early Continental engines. These pumps feature all new parts including castings, and rocker arms. These pumps have a one year or 1000 hour warranty.

Overhauled Tempest (Continental) Fuel Pump  These FAA Approved overhauled pumps are built to factory new performance specifications and have a one year or 1000 hour warranty. They are offered at a lower price because we use serviceable castings and rocker arms. All other internal parts are new FAA-PMA replacements.

Q: Is there a mandatory replacement time for diaphragm fuel pumps?
A: Diaphragm fuel pumps should be replaced or overhauled at engine TBO or after ten years in service, whichever occurs first. Replace on condition if leaks develop or performance drops for example.

Q: Which Fuel Pump is correct for installation on my aircraft?
A: Please refer to the application charts on the fuel pump page to find the correct pump for your aircraft. If you or your mechanic will supply us with the aircraft make, model and engine type, we will be happy to provide you with the applicable pump for your aircraft (call 1-800-822-3200 or e-mail gehrlich@aeroaccessories.com).

Q: I have just installed my new Fuel Pump and my engine will not start. Why?
A: A common cause for this problem is fuel starvation due to improper installation of the fuel pump. Make sure that the fuel lines are not crossed; that is, the inlet line should be connected to the inlet side of the pump (marked “IN” on the top of the port) and the outlet line should be attached to the fuel pump outlet port. Fuel should be present at the inlet side of the fuel pump.

Improper installation of the fuel pump may result in a misalignment of the operating lever with the operating plunger in the accessory case. If so, there will be no movement of the lever and no pumping motion to provide fuel flow. If misalignment is found upon removal of the pump, the lever is probably damaged or broken. If misalignment of the operating lever has occurred, it will require inspection and repair by a qualified technician. If you would like to have Tempest/Aero Accessories Inc. perform repairs on a broken or misaligned lever, please contact us at 1-800-822-3200, Mon.-Fri., 8am-5pm Eastern Standard time, or e-mail us at gehrlich@aeroaccessories.com.

Q: What is causing the fuel (or oil) to leak from my Fuel Pump drain line?
A: Leakage of fuel or oil through the fuel pump overboard drain line indicates a worn or ruptured diaphragm inside the fuel pump. The fuel pump should be replaced before further flight

Q: What is causing my fuel pressure to fall below the “green arc”?
A: The most common reasons for low fuel flow/pressure are the following:
1. A worn or broken O-ring on the inlet side fuel fitting can cause an inlet suction leak. An inlet air leak will result in low Fuel Pump output pressure.
2. A weak operating spring in the Fuel Pump diaphragm assembly;
3. A worn fuel pressure gauge;
4. A clogged fuel vent or fuel cap;
5. A constriction in a fuel line either externally (a kinked hose), or internally (due to a collapsed hose lining).
6. Wrong fuel pump for the installation.

Q: What is causing my fuel pressure to fluctuate?
A: Fluctuating fuel pressure can be the result of the following:
1. A worn fuel pressure gauge;
2. A worn or broken O-ring on the inlet side fuel fitting;
3. A defective fuel selector valve (boost pump may labor);
4. An obstruction in the induction system (air intake);
5. A clogged or dirty fuel strainer;
6. Foreign material inside the fuel body (such as fuel cell sealant, thread sealant, or a drill shaving).