Rear leak on Trailblazer Ext
 

There is a coolant leak on the rear of my 2003 Trailblazer Ext. It appears to be coming out of a black valve on the passenger's side. Does anyone have a clue as to why this is happening? It just started when the temperatures started to get into the 90's.

I am experencing the same thing on our 2002 Trailblazer Ext LS. We have also had the rear A/C start to click on and off whenever the car is first started for about 3 mins. It sounds like the solenoid or relay is turning on and off. We are not able to ustilize the A/C anymore, it only blows hot air.