Lefoo lf10-4h2 pressure swith for air compressor

Well, chances to find actual working drawings of a part that's an integral part of a larger product are rather slim. If the way to put it back together is not apparent, you may need to look for a replacement:   Lefoo LF10-4H2 pressure switch comes up with these specs:

MODEL : LF10A-4H2

Min ON   (Cut-In)PSI: 35

Max Off (Cut-Out) PSI: 150

Differential PSI: 30-40

Factory Setting  PSI: 85-115 Electrical Rating: 26A Pipe Fittings: 1/4"  Female NPT (4 Port)

Contact Arrangement: Normally Closed

I honestly don't know who sells the Chinese Lefoo parts here on this side of the pond. But you can't go wrong with Square D and here is a very similar switch(though not the same, so you may look for a better match) :

Also, check out their video on choosing replacement pressure switch, very nicely done and informative:

Most manufacturers recommend that the tank of the compressor be emptied daily. As the machine takes in air, it also takes in moisture from the air. The moisture builds up in the tank and forms condensation. Condensation buildup can corrode the tank, leading to all sorts of problems and eventual failure of the machine.