1998 Chevy Blazer Trans and coolant leaks HELP!

1st thing is 1st. Lets start with one leak-coolant. Check the passenger floor for dampness. If its wet, then the heater core is no good. If its dry, then it may be the lower intake gasket which is common. Dont rule out something simple like a radiator hose, or radiator. Those components will usually leave a residue around the leak, and drip enough to puddle on the ground. If you cant find any leaks, I suggest buying a coolant pressure tester available at any parts store (usually between 80-120$) and you hook it up to your radiator as you would any radiator cap. This puts pressure in the system, and helps when locating coolant leaks.

If its only a little over filled, dont sweat it, if its quite a bit over, then remove your tranny cooler line, and drain some fluid out. (Passenger side of radiator)

as far as the intake goes. You make the gasket for the front and rear. The tube of rtv they gave you throw out! I use this stuff called "the right stuff" gasket maker. Its a very good silicone. Not sure who makes it, but im sure if you google it you can find out. Get it in the cheese can. You press the end of it, and it comes out like that cheap cheese in the supermarket. Make a thick bead about 1/4"tall and as wide as the block. Also push it right into the corners of your new gaskets.

Make sure all surfaces are down to bare metal. Spray brake clean on a rag, and wipe clean before you do anything. I never put anything on a gasket, unless I absolutely need to. If I do, I use a small about of "the right stuff" and smear it with my finger so its as flat as possible. Its only purpose is to keep the gasket from sliding, not to seal it. When your ready to put the lower intake on, be careful. It has to be put on almost with a surgeons accuracy. Once in place start all bolts by hand. Then proceed to torque specs.

Glad everything went well for you. I would run the truck with the cap off at idle for a while, keeping an eye on the coolant level, and adding as necessary. Also, if you havnt already, I recommend throwing in a thermostat. They are easy, and cheap. And a VERY important part of your cooling system. Let me know the results.

Ive seen really wild things happen with s-10s. For example, a 1994 (old body style) has 2 knock sensors, one on the back of each cylinder. They have 2 coolant temp sensors. 1 for the computer (the little one on the lower intake manifold) and another for the gauge that is on the driverside of the engine, between the exaust manifold. Looks identical to a knock sensor. I did an engine swap in one of these, and everything was fine. Except the temp gauge said it ran 30 degrees cooler than it actually was. Sure enough, when transfering the sensors from the old engine to the new engine, they had a plug where the temp sensor (for the gauge) would go, on the driver side of the engine. I put the knock sensor in that spot, and the coolant sensor in the back of the head-where the knock sensor would go. Keep in mind the knock sensors, and the coolant sensor for the gauge are IDENTICAL! That was also on a 1994, it has changed since then. But that goes to show that these things arent as simple as everyone thinks.

Back to the subject, your truck doesnt have any air-bleeders on the upper coolant tube like a 3.1, 3.4, 3.8 liter engine. The air will be pushed out by the waterpump. You said your air is only warm, not hot. It should be hot. Change the thermostat, and while your in there, use a garden hose, and flush out the system. Use a drain pan of course. 1st flush the radiator, remove the lower radiator hose from the water pump, and remove the upper radiator hose, blast water through the radiator through the upper radiator hose. Make sure you have adequate flow out of the lower hose. The block usually never clogs up, but its a good idea to flush that out as well. After that, undue both hoses that goe to your heater core (they are located on the firewall one above the other) make sure u have adequate flow through that. At this point, make sure you change your thermostat. Should have no more problems. This process, along with replacing the thermostat should take no more than 1 hr. I feel as I am writing a book, hahaha. Let me know if this solves your problem. Good luck!

Im glad to help, and im very happy everything worked out well for ya. Thanks for the appreciation, a thankyou goes along way!