I was working on a 6-ton Water Furnace geothermal unit the other day, & diagnosed the compressor as open, so we are going to replace this part next week. The question I have is that this unit has a couple of really strange gauge ports on the high and low pressure lines. These valves are deeper than the usual Schraders, and don't open (or even move) if you try to press the top. No Schrader tool I have will work these valves. I won't be able to put my gauges on them. Is there a special tool required to work on these? I need to know before we change out the compressor next week. Thanks.