After having 2 = coolant leaks, rear heater and a oil cooler hose, I decided to monitor my coolant = systems pressure. I installed a couple of extra senders for the electric oil pressure gauge and a switch so I can now = monitor my oil, fuel or coolant pressure. The coolant pressure is 0 when cold and = slowly rises along with the coolant temperature to around 10 psi, I assumed it = would sit around 10 psi while the engine is hot. Yesterday was the first = time I have taken a long trip, about 3hrs since installing the sender. = After climbing to 10 psi it started dropping off gradually after 30 minutes of driving to 2-4 psi and stayed there the rest of = the trip, it did the same thing on the way home. I appeal to the wisdom of = the list, do I have a problem? I can find no coolant leaks, drips or drops. Temperature here has been in the 20- 40 degree F range. Any ideas = sought and appreciated.