Leaking Antifreeze in the cab of my 1999 Chevy S-10

My 1995 chevy s-10 began leaking antifreeze inside the cab. The leaking is coming from the underside of the dash board on the passenger side. I was hoping some one could possibly tell me what I was looking at as to the cost and the complexity of fixing it on my own?

So your heater core is leaking.

I’ve never changed one on your specific vehicle, but I did change one on a '96 GMC Jimmy.
If your truck is anything like the Jimmy, actually replacing it can be a real pain in the neck. …but it can be done… if you’re crazy enough to try. The problem is, the heater core probably has a cover on it, and there’s not enough room up under the dash to remove the cover and remove the heater core without hitting other elements of the dash assembly.

As far as cost, if you do it yourself, all it costs is the price of the new heater core (prob. approx. $60).
Labor is extensive though. Maybe someone knows easier ways to do this, but it was my first (and last) time at this job. In my experience, this is what I had to do:
First, you’ve gotta drop the steering column, and then unbolt the entire dashboard from the vehicle- which may entail removing the speakers, glovebox, center column, radio, etc…so you can get to the screws and bolts that hold the dash on. You wind up w/ A LOT of little screws and bolts which you’ll need to keep track of and remember where they go.
Then, you’ll probably have to lift the entire dash assembly up and out- as it rests on these little hook thingies on either side of the cab. I accomplished this by using two floor jacks (one in the driver foot well, one in the passenger foot well) to raise the dash up evenly and then slowly rolling them back just a few inches until I had enough clearance under the dash to remove the heater core. Of course you’ll also have to remove the hoses from the core (access these through the engine bay- they go into the core through the firewall).
Put the new core in, then just reassemble everything.
If you go this route, I hope you have small hands and lots of patience.

Another option you have, if the winters are mild in your area and you think you can live without the heater, is to take the heater hoses (mentioned above- in the engine bay that go into the firewall), disconnect them from the heater core, and just reroute them into each other w/ a hose coupler (picked up at most any Autozone or Home Depot).

Of course your third option -and the one I’d recommend if you think heat is necessary, is to get it fixed professionally. I don’t know what the labor costs for that might be, but I imagine it’s expensive.

VelocityBoy is right on target. When I had a leaking heater core on a Taurus, the parts were really cheap and the labor was REALLY expensive. IIRC, I paid something like $650. in total for the repair, and that was in 1991!

The heater core in my S-10 has been replaced twice. The first time I had a shop do it, they charged $650 total. They broke my hazzard light switch, but that’s another story. 2nd time I did it myself, cost was $40 for an aftermarket core. It is a little daunting at first but it’s not that hard, I did it in 2 or 3 hours.

Get a Haynes manual, it shows the entire process. You have to drop the steering column and remove the dashboard. The dash is mounted on swivel posts. I was able to move the dash back just far enough to get to the heater core without removing all the wiring. I still had to disconnect a few things though. You need a torx driver for some of the dash screws. Change all the hoses if they’re old. Go for it and save $600 bucks.