It could be time for replacement. They do get washed out after time. So the question you have is do you go the same route and stay with the Lex-Airs or are you going to replace with a solenoid valve? Lexairs are around $400 for the smaller style pistons and the bigger piston style is about $550. I understand the electronics are about 250-$300.00. I think I am going that route when the next one goes bad. Who has that part number?