The diaphragm may be sitting in the body or captured in the bonnet. Remove the bonnet, diaphragm, spring, and support ring. Note the orientation of the individual parts so you can properly reassemble them. Examine the diaphragm and spring. The diaphragm should be clean and free of wrinkles, tears, and perforations. The seal should be clean and free of nicks, dents, and abrasions. Wash the diaphragm with clean, fresh water to remove any debris that may have been deposited there. The diaphragm spring should be intact and bounce back when compressed.