Thanks for the post!

So, you ordered the AB-9040019 Piston Ring and the AB-9429999 Valve Plate Assembly? If so, these parts certainly should have restored compression (unless they were installed incorrectly).

What version of this model do you have, Type 1 or Type 2?

You can see the differences by clicking here:
www.mastertoolrepair.com/search.php?keywords=H1506F+

The Type 1 units were typically manufacturered before May of 2008 and had a single valve plate with a "3-fingered" reed valve on top. The Type 2 unit has the newer twin-valve plate design.

- MTR

That would be the correct kit, yes. Is your compression ring in good shape? Any small fold or tear on the perimeter of the ring can cause low compression as it won't provide a good seal in the cylinder.

Otherwise, make sure the valve plate isn't installed 180 degrees the wrong way. It seems you installed it correctly but just to be sure you'll want to contact the manufacturer directly at 800-556-6696. This is Stanley Black & Decker (DeWalt/Bostitch).

Just tell them you have an "OL195 oil-free pump" and you ordered the AB-9429999 kit and relate to them the problem. It's a bit difficult to say being I don't have it here in front of me to inspect.

For reference, we have a video and tech doc that may help, just click on the below links:

www.mastertoolrepair.com/images/Bostitch...change_OL195_new.pdf



- MTR