My Harbor Freight compression tester is probably close to 30 years old, last time I used it it worked fine but that was probably a dozen years ago! If I ever need it again and it is dried out I will just buy another one which should last me until my nursing home days.

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Brian
87 300Dturbo 180K #14 head still running R-12 SOLD 12/2017
02 F350 Powerstroke 180K
05 Chevy Express 1 ton w/Royal Utility box 120K
08 Infiniti FX-35 40K
15 Golf Sportwagen TDI 35K
10 Sprinter 3500 chassis with a Class A Winnebago on it. 56K

Guess I'll head to HF and get one!