Not sure what you are talking about. If you are referring to a part in the engine then the piston does not have a return spring. If you are referring to the piston, not quit the right term, in the brake area then in the wheels the there is a spring and in the actuator there is a spring. No other item I have ever heard of as a piston return spring. Can you elaborate?
under the air intake close to the transmission
The same thing muffler bearings and blinker fluid does.
In a 1972 VW 1600 engine, the oil pressure control spring and piston are located in the oil pump, specifically in the oil pressure relief valve bore. The oil pressure relief spring and piston are also part of the oil pump assembly, with the relief spring positioned above the relief piston. Make sure to install the correct spring and piston configuration according to the specifications for your engine to ensure proper oil pressure regulation. Always refer to the service manual for detailed guidance on installation and specifications.
air operated- spring return
The Nitro piston is superior to the spring piston in design, but Yes, it can be converted back to a spring in most cases. It is best to have it done by an "air gun smith."
spring drives a piston that pushes air
When you cock the rifle it compresses the gas behind a piston just like a spring. Basically it replaces the spring.
When the rifle is cocked, a spring is compressed. Pulling the trigger releases the spring, which pushes a piston forward, The piston compresses air as it moves. The compressed air blows the BB or pellet out of the barrel.
It's about the same. Nitro will just perform a little better. No spring to wear out. The Nitro piston guns have a sealed strut in place of a spring, there's no maintenance required.
Three.. bolt carrier return spring, trigger return spring, magazine release return spring.
It is a spring metal sleeve that goes over a piston to compress the rings so that the piston can be install in the motor. It tightens down on the piston, forcing the rings into the grooves in the piston then you tap it into the cylinder.
Piston and spring.