Mitre-Mite VN42 Regulator leak fix

[JohnMiller]

Hi all, the regulator (part #735630002) has developed a noticeable air leak when the cap is pulled up to adjust, and a lingering faint leak when pushed in to lock. Short of replacing the regulator, is it feasible to perhaps dismantle and replace o-rings (which I assume is what seals it)? Thanks!

 

[Underpinner Spares]

The diaphragm can be replaced but these rarely cause issues as the biggest problem with that brand of regulator is plastic fatigue which results in hairline cracks allowing the air to leak, you would be better off replacing the entire regulator.

Mark

 

[Mike Labbe]

We had one develop the same problem, years ago, and replaced it. They start at $12 on Amazon, or the OEM is available from Fletcher:

Pressure Regulator (735630002)

Used with AMP's U-300 Underpinner (Former Model VN2+1), U-300P (VN4L), U-400 (VN144), U-500 (Former VN4MP), U-600 (Former VN4MC) and VN42

shop.fletcher-terry.com

We also had a (different) problem with the main piston getting stuck returning to the home (high) position, with our VN42, after a cycle. This has happened 2 or 3 times over the years, and the solution was to disconnect the air, drop the piston out from the bottom (2 bolts), wipe it down, and put it back in. There was some residue on the piston that was causing friction, and the valves were stuck between cycles because of it (and exhausting air out one of the muffler ports). Fortunately, this hasn't happened again in about 10 years. I'm only mentioning it in case you see this behavior in the future, too.

Welcome to the G, John!

Mike