I've got a 95 blazer, v-6 vortech, 4x4 that started leaking coolant excessively a couple weeks ago. i just parked it for the time being and stopped driving it. Recently i went out and started it and noticed it's not only leaking, but it idols very low now, to the point where it almost shuts off, And the temp gauge constantly is going up and down resulting in little heat to the cabin. When the car temp rises the heat doesn't work. I also moved it out of it's parking spot and as I applied the brake, it was very stiff with little play and didn't really work. Any ideas on what this could be? Any help is much appreciated, thanks, Tony

 

Based on the stiff brake feel and low idle I'd guess you have a large vacuum leak somewhere.

You mention that it began heavily leaking coolant and now you don't have heat. Where is it leaking from? My 99 blew the lower intake manifold gaskets causing a similar problem. Once the leak is fixed, top off the radiator and burp the air out of the system. I used a Prestone coolant flush adapter to remove the air from mine. This should bring the heat back.