Are you still having issues with this? I did not see a DataLogger report on the post but I'd be interested to take a look at it. It is fairly normal to see some pressure fluctuation during the cool cycle but it should not be severe. If the motor cuts out completely that would be an indication that the internal time/temp parameter controls are shutting the motor down, especially if cycling the power switch resets it and the motor comes back on. If the pressure is fluctuating severely that my be harder to troubleshoot.
One common problem is that there are some internal fittings that come loose and allow fluid to bypass which results in the machine not keeping pressure. Shoot us an e-mail at
techsupport@mcelroy.com and we can take a look at the DL reports and go over some of the possible issues. Thanks.