Alright, 1998 blazer

The other day after I got out of my truck from a short trip to town I parked in my shop, and noticed a good sized puddle of fluid, so i felt it and it looked like water but was a little thicker and smelt some what like anti freeze. Been fine for a couple days but today coming home from work the heater wouldnt work. The fan was cranked and and blowing cool air. Then I turned it off for a few mins and turned it back on and all the sudden blowing hot air again, but only laster like a minute. Now I noticed this before that when I turn it to floor defrost, the fan turns off and nothing happens but when defrost on the window the fan runs. So as of now I have no heat and the floor setting dont work.............What you think is wrong.

paxfam

If the coolant dropped low then the core maybe full of crap now so flush it and hope it doesn't leak. Also check the vac lines under hood on drivers side as the final connection is to the plastic line to the heater controls. Find the leak now so you don't destroy the engine - core, hose, waterpump, lower intake gasket or radiator.

alrighty.............Checked coolant lvl today and found it to be way low............ So chances are this is my problem. Would it be a good idea to flush the core anyways? I dont want it to start leaking though, do you just pull the lines off of the core and run water threw them? How do I even start looking for a vacume leak????

Now you must locate the leak. I put a large enough piece of cardboard under the front of the car to catch anything from the motor after driving it around enough to fully warm up.

alright found the leak, its coming from the water pump...............I was able to touch that seal thats between the pump and the plate thats on the back of it, and I think its leaking there. The seal is wet/soggy, and where that seal is dry its very brittle. So I guess I will have to tear this beast down, and I will just throw a new pump in, autozone has remans for 35 bucks. How do I go about removing the old pump, remove radiator ect............

How do I go about removing the old pump, remove radiator ect............

The anwer's in the How-to (http://www.automotiveforums.com/vbulletin/forumdisplay.php?f=2069) section:
96+ Water Pump Replacement (http://www.automotiveforums.com/vbulletin/showthread.php?t=498467)

Is that a common place for them to start leaking?????? Just woundering why that back plate is even on there?????

Actually, there's a weep hole under the water pump that normally leaks. The coolant then runs back and makes it appear as though the plate is leaking. When you get the pump off, you'll be able to see the trail of coolant from the weep hole to the plate.

So what your saying is that the pump is actually internally damaged.........Why would they put a weep hole there?

paxfam

It's there as an early indicator of problems. It tells you that the seal inside is bad and the bearings are compromised.

Replaced water pump today, leaks gone and heater is working excellent!!!!!!!!!! Thanks boys!