New Fuel Selector Valve Assemblies
FAQs for "New Fuel Selector Valve Assemblies"
Frequently Asked Questions
How do I keep contaminants out of my fuel system?
The fuel selector valve works in unscreened fuel. Contaminated fuel can cause selector valve seal damage. When fueling from possibly contaminated fuel sources McFarlane recommends the use of a fuel filter, such as Mr. Funnel or another filtering device, to reduce trash in the fuel system.
How do I know when to replace or service my fuel selector valve?
The most common indication of external fuel valve leaks is the smell of avgas in the cabin. Most valves are located under the cabin floor. Fuel stain on the valve and drain plug or drain valve or on the belly of the aircraft can also indicate external leakage. External leaks are generally around the actuation valve stem. Internal leaks are detected when the fuel is turned off and fuel continues to drip during fuel system maintenance. Inner port leakage will allow fuel from one tank to leak into another fuel tank. This type leak is difficult to detect. Fuel transfer from one tank to another with the fuel valve selected to one tank only will indicate inner-port leakage. An extended period of time is needed to detect fuel transfer from one tank to another. Generally if internal leakage is detected when servicing the fuel system, it is likely there is also inner-port leakage.
What pressure is used to test the fuel selector valves after repairs?
We pressure test our repaired valves to a minimum of 5 psi using precision controlled air pressure and a calibrated low pressure indicator. This pressure is above the normal fuel pressure on the valve and below the limits of the springs in the valve. Each valve is submerged in Stoddard solvent while the air pressure is applied to the valve. The valves are then tested in each position to assure that there are no inter-port or external leaks. Leaks are detected by looking for air bubbles escaping from the valve.
Proven Design with Improvements
Improved corrosion resistance: McFarlane’s new valves are totally anodized where the original valves were Alodine conversion coated. This change drastically improves the surface durability, wear resistance, and corrosion resistance of all the components, and they will stay pretty too! Corrosion protection is important since the valves are at the lowest point in the fuel system without any upstream water separation or contaminate screening. We have also eliminated the brass bushing that corrodes the cam.
Improved O-ring retention: Modern machining processes lets us precision machine the O-ring capture cavity. The original valve O-rings were retained by staking (stamp forming) the housing. This process was inconsistent at best and distressed and weakened the surrounding aluminum structure.
More balanced fuel flow: Yesterday’s manual machining process of the original valves were often inconsistent enough to let one port flow more fuel than needed while the other port might flow a very marginal amount of fuel. The new McFarlane valve is computer machined for a perfect balance of fuel flow.
Fully Tested: You can rest assured that if it’s a new McFarlane valve or a valve repaired by McFarlane, it will be pressure, functional, and flow tested to perform to the highest standards.
Now for more good news!!
All of the improved parts that go into our new valve are interchangeable with the original Cessna valve. This means that if your valve is good with the exception of a few parts, we can fix it at a reasonable price! Whether you need your valve repaired or a new valve, McFarlane will save you money.
Why not just repair my valve?
Many of the original valves have too much damage to be repaired cost-effectively. The original Cessna fuel valve that started in model 170 was a simple but ingenious cam ball design that has proven very reliable over the years. McFarlane has repaired a lot of these original Cessna valves, and we know them well. However, we are now rejecting a big percentage of the valve cores sent to us. A lot of them have corrosion damage in the main body that is too severe to fix, or the O-ring retention area is damaged and too rough to seal. Many of the fittings are corroded through. The cam bearing is brass and easily corrodes the aluminum alloy cam. Due to the poor condition of many original valves, McFarlane developed a totally new valve that was designed just like the original valve but with improvements where needed.
Why choose McFarlane?
OUR PARTS ARE ENGINEERED TO LAST LONGER WHILE SOLVING KNOWN SAFETY ISSUES
OVER 40,000 PARTS IN STOCK WITH SAME DAY SHIPPING IF ORDERED BY 3PM
OUR TEAM PROVIDES THE OLD-FASHIONED CUSTOMER SERVICE THAT YOU EXPECT
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