Check speed selector located on the top of the drill (see image)

Slide speed selector to 1, make sure speed selector is flush. (see image)

Press trigger for 3-5 seconds.

Slide speed selector to 2, make sure speed selector is flush. (see image)

Press trigger for 3-5 seconds.

Verify if the grinding sound is still present.

Tip: Prior using the drill make sure proper torque setting is set and speed selector is properly engaged.

Check for external air leak. Identify the part that leaks using your manual's parts diagram (you may download a copy by visiting our Manuals/Documentation section). If external leak is not present the problem could be a bad reed valve.

To check your reed valves, please follow the steps below. We have provided a video here to help you navigate this inspection process.

Tools needed:

Screwdriver, Adjustable wrench, Ratchet wrench and sockets (sizes differ per model), Teflon Tape

Turn OFF and unplug the compressor.

Remove motor shroud (see image).

Disconnect high pressure tube from the cylinder head using adjustable wrench (see image).

Use ratchet wrench and socket (sizes vary) and remove head bolts (see image).

Locate valve plate (it's located in between the cylinder head and cylinder approx. 1/8" thick - see image).

Remove 2 Phillips-head set screws (see image)

Inspect Intake Reed Valve (U-shaped - see image) and Exhaust Reed Valve (Tongue-shaped - see image) to see if it's cracked, broken, bent, or it if has heat marks. If so, replace with new reeds (When replacing reed valves it's suggested to replace both intake and exhaust reed valves at the same time as well as necessary head gaskets). You can purchase replacement parts by visiting our parts e-store here.

Reassemble your unit in the reverse order. To avoid an air leak, use Teflon tape when connecting the high pressure back to the cylinder head.

Plug the compressor back in and turn ON, check for leaks.

Let the compressor build air to its maximum pressure. Leave switch to the AUTO/ON position, it should automatically turn OFF once it reaches the max pressure (approx. 90-115 PSI).

Relieve some of the air from the tank (either by draining it using a drain valve located either on the bottom of the tank or on the manifold or by using an air tool). The compressor should automatically turn back on once it reaches cut-in pressure.

Tip: You may have dirty water release when you relieve the air from the tank. Use a bowl on top of a large piece of cardboard or towel to collect the water and protect your floor.

Batteries have shelf life regardless if it's used or not. A typical shelf life of a battery is approximately 3-4 years. You may conveniently order replacement batteries through our e-store.