Our pump will operate gear just like factory Prestolite units. It has an aluminum self-contained reservoir that uses 5606 hydraulic fluid. Pump mounts in the same physical location as a HYC5001, HYC5005 or HYC5006 powerpacks. Our unit connects to all three aircraft AN-4 hydraulic line fittings (Gear Up, Gear Down and Return/Dump), Pump wiring uses the same 3 wire aircraft power circuits (GREEN, BLUE and BLACK). Pump operates with your panel mounted Gear UP and DOWN switch just like factory gear pump. Our pump builds the same pressures in both hydraulic circuits as the factory gear pumps (HYC5001, HYC5005 and HYC5006). You will not be able to tell the difference between our powerpack and the HYC5000 series powerpack. With the exception, ours costs about 1/6th the price, it's a better unit, bolts in easy, is quieter, comes with installation instructions and has thousands of test cycles. For the last 30 years it has been used for retractable gear operation on high performance experimental aircraft (Velocity, Berkut, E-racer, Long EZ and several others. It is even used on some 114B Commanders and Piper aircraft with a different hydraulic reservoir. This unit has been in service for over 30 years on other aircraft, flying the same sky's and landing on the same runways as your aircraft.
Our unit is being sold as a "maintenance powerpack". It is for cycling the gear up and down while on jack stands". Although, it could be considered an owner supplied part and installed with a 337 since Piper no longer supports its aircraft with NEW Powerpacks.
Our gear powerpack comes with the mounting bracket, aluminum reservoir, tubes and fittings to complete a basic install in just a couple hours. You will need a tube bender and 37 degree flare tool to make the connections from the airplane to the pump. If you don't have the tools, it's 200 dollar investment. Thats a lot cheaper than a Prestolite pump overhaul.
I would like to provide a little insight to the Prestolite Gear Powerpacks; They haven't made these units in over 40 years. The price for overhaul has gone from 1500 dollars to as high as $3,950.00 in less than 4 years. Core exchanges are between $3,000 and $3,500. The overhauled HYC5000 series powerpacks are only lasting a few years when returned to service. I'll explain why this is taking place. First, the repair shops are all price fixing, allowing them to gouge the consumer. They know there are no alternatives to these Prestolite powerpacks. However, there is another issue at hand, I told you they haven't made these units in over 4 decades. Let me explain what is transpiring at the authorized repair shops.
I spoke with an authorized powerpack overhaul shop, not going to mention the shop as I told tech I would not share the facility name. I will say this is a large repair facility that you have most likely heard the name many times. The reason there is a 3500 dollar core charge for these pumps is, they cant get replacement parts, they are not made anymore. I'm talking about the aluminum pump casting and the aluminum base to the reservoir. They can get the DC motors. for under 60 dollars and or the small motor parts (brushes, bushings, seals, etc...) for a just a few dollars. All those are common parts for many other DC motor applications. However, the parts that take a beating like the actual shaft driven hydraulic pump that mounts to the units base and the aluminum valve body that is cast into the base plate are not available. The balls and springs are also common replacement parts, but they don't go bad. So, when they sell you an overhauled powerpack, you're getting a DC motor with brushes, bearing and the armature commutator turned flat, about 12 dollars in parts. Fields out of another good case, only if it needs new fields. You are not getting anything new in the pump assembly except maybe some .30 cent springs and some .50 cent steel balls and about 45 cents in O-rings. I forgot to mention, there is still one manufacture making the Gear UP lock valve, but they will not install that unless the pump needs it.
So, these pumps are failing more frequently, yet the price keeps going up. This is because they are running out of functional/used cores to steal parts from. You're getting the best of the warn out parts they take in as cores. What a wonderful system, 3500 dollars, plus a 3000 dollar core charge and you get back someone else's defective worn out pump parts that are just functional enough to pass the bench test. Once you bolt in the plane, GOOD LUCK! We are all dealing with the same used, worn-out Prestolite HYC5000 series pumps.
This new powerpack was selected and modified by an engineer that designed components for the automotive industry for several decades. He is also an A&P and has worked on aircraft for over 40 years to include US military aircraft. In addition, he holds a commercial instrument rating in Multi Engine fixed wing and Turbine Helicopters. He was a US Army Maintenance Officer and attended the US Army Test pilot school in Ft. Eustis VA. He also has dealt with Prestolite pump failures and understood there needed to be an affordable alternative solution.
Call me for more information.