If your pump is over 5 years old replacing the magnetic arm along with the diaphragm and valve block will restore your pump to almost like-new condition. The magnetic arm is controlled by the electric coil and flexes back and forth to move the diaphragm and create the pumping action. These arms are spring steel and over time lose their strength. The RA400 ( 702E )replacements consists of two pieces, one arm for each diaphragm. Color may vary from the picture above.
Replace the Magnetic Arm to make your Rena Air pump work like new!