I have a 99 S-10 4x4. I am beginning to loose coolent. I am not sure exactly where it is leaking from. It looks like the vecinity of the water pump. I noticed a little bit of rustiness on top of the pump. My engine is clean so it looks like water had to be there. I haven't known them to leak on top only through the hole on the bottom. Any ideas if it could be something else? It is not leaking a lot. I have to top it off every 2 or 3 days.

It could be your radiator cap. they are known for being bad.

Could be the infamous intake gasket as well.

If the water pump look at the bottom hole from underneath while its running. If the intake check the front between the block and intake right above the water pump and also it may leak into the "V" between the valve cover and intake so use a light and look there too. If its the V and you park on a grade it runs down front or rear (front down hill then runs down the front). Also, there is the famous leaking heater core but you will smell that one in the cab. Any hose could also spring a leak but so far never had one leak in my 4 blazers 98 up.

Go to AutoZone and rent or borrow the pressure tester. Pump it up to the pressure rating of the cap. You shoulld be able to find the leak real quick.

Could be the infamous intake gasket as well.
I agree. Also if ur pump was leakin u would prolly have heard it b4 u saw it.

its either the water pump, doubtful, never seen one leak from the top, could be a hose, could be the intake, if its the intake feel lucky, i checked the oil in my show truck today, and it was chocolate milk colored, my moter is now a boat anchor, when it goes outside like yours did if its bad, nothing bad happens, gaskets need changed, the bad news is if you dont want to do major engin work, its going to cost you between 650 and 1200 usd

It "only" cost me $387 to get my intake gaskets changed at the dealer. Couldn't believe it. Dealer was cheaper than the independent shops.

I also had a coolant leak when I 1st got my 98 Blazer 4x4 (around 100k miles). Mine was leaking from the hose (top one, I think) and the waterpump. It probably would have been fine if I would have just changed the waterpump gasket, but while it was apart, I just changed the pump. Easy job.

My 1996 has the "weep hole" on top of the water pump it was leaking out of there and then running down the sides.

a new water pump is cheep enough to just change it, not worth doin just the gasket

I changed the radiator cap a few months ago when I read the post about it. If the intake were leaking wouldn't there be water in the oil? It is supposed to warm up in the next couple of day and I'll take a look at the hoses and look a the water pump real good and we'll see.

depends, the jacket can split two different ways, one is yes into the oil, that happend to me, but, by pure luck i watched it happen, checked my oil, changed it, ran it for filter fillup and then a final check and the intake had popped, couldn't be any luckyer... the other way is the jacket can pop to the outside and seep out quite good from the base of the intake and the heads