'98 Jimmy leaking coolant (dumping, really)

I just sold my brother my '98 Jimmy 4.3L 4x4 and of course it begins to disintegrate immediately...

One day the heat didn't work so he took it in to a mechanic. They told him (among other things) that it was the water pump and it would be $500 CDN. He got them to do some other stuff to it but could not afford the pump until the following month. They topped up the rad and put in stop-leak. I see from some of the hits to my search that stop-leak may not be a great idea.

In any event, two days after they did that, he drove for about 40 KM's and the rad let the antifreeze go all over the parking lot.

He is driving my van for the weekend and I need to know if the water pump solution holds water (pun intended). If so, I am going to go buy the part and the gasket kit but need to know if this is something I can do in my garage myself. I see one post that says anything but the heater core is do-able. I used to do all my own work on my older vehicles but other than changing pads on the disc breaks, I haven't done anything to the Jimmy. Are there any suggestions or caveats?
Thx.

Can you tell where the anti-freeze is coming from? If it is leaking from the water pump's weep hole, that is a sign that it is time to change the water pump. The water pumps on the 96+ are not hard to replace.

Here's a walkthrough:
http://www.automotiveforums.com/vbulletin/showthread.php?t=431110

If you don't mind waiting for the page to load, devilman13xx took some great pics and added them to my walkthrough here:
http://www.s10forum.com/forum/showthread.php?t=198215

The heater not working could be a result of a few things. The two most common causes are a thermostat that is stuck open and a clogged heater core.

If the engine is warming up completely (the gauge should read one click left of 210) and the heater's blowing cold, that's a sign that the heater core is clogged, usually a good flush will get it back in working order. If your coolant is old or dirty, I suggest that you flush it anyway. This is the flushing method that I recommend:

For normal maintenance:

Buy the following:
2 gallons of distilled water $1
2 gallons of antifreeze $20
Prestone Flush 'N Fill kit $3
Prestone Radiator "Flush" $3

Turn your heater on and leave it on for the entire process

Drain the antifreeze from the system.

Install the "T" from the Flush 'N Fill kit and follow the directions that came with it.

Disconnect the water hose, close all the drains, add the Prestone Flush, fill with water, get engine up to operating temperature and run for 20 minutes, allow to cool then, drain the system.

Connect your water hose to the Flush 'N Fill "T" and flush one more time. Drain.

Fill the system with a 50/50 mix* of antifreeze and distilled water. Continue to fill the system over the next few days as the air is worked out of the system.




For clogged, neglicted, or extremely dirty systems:

Buy the following:

2 gallons of distilled water $1
2 gallons of antifreeze $20
Prestone Flush 'N Fill kit $3
Prestone Radiator "cleaner" not "flush" $4

Turn your heater on and leave it on for the entire process

Drain the antifreeze from the system.

Install the "T" from the Flush 'N Fill kit and follow the directions that came with it.

Disconnect the water hose, close all the drains, add the Prestone Cleaner, fill with water, run the engine 3-6 hours (you can leave it in for a few days if neccessary), drain the system.

Connect your water hose to the Flush 'N Fill "T" and flush one more time. Drain.

Fill the system with a 50/50 mix* of antifreeze and distilled water. Continue to fill the system over the next few days as the air is worked out of the system.


*When you do your final drain and fill....not all the water will come out so to get the proper 50/50 mix you should add the right amount of straight antifreeze then top off with the distilled water.

If your temperature gauge is reading less than one line left of 210, then the lack of heat is most likely due to a stuck thermostat, they are pretty simple to replace. The thermostat is located in the housing where the upper radiator hose enters the top of the engine. Make sure that you drain about a gallon of antifreeze before you start and it won't be as messy. You just remove the bolts and pull the housing (goose neck) and the thermostat is right there. Pull out the old one a drop in the new one. (make sure that the new one comes with a new gasket, if not, you will need to purchase it seperately.) Close it up, refill the antifreeze and you're done.

I forgot to mention.... due to defects with the original AC DELCO radiator cap, it is recommended to get a new 16psi "Stant" radiator cap. Advance Auto sells them for $5 - $6.

I just pulled the plastic piece off from under the rad. I cannot see a leak from the water pump at all but nor can I see any other leaks in the hoses, etc.

I can't see under the pump due to the crank shaft pulley so it must be coming from there.

I will look through your links and perhaps it will all make sense.

I will go get a water pump, thermostat and cap right away before the parts store closes and will give it all a go.

Thanks a bunch for your quick reply.

Kent

Odd. I just drove it across town and back to get the parts and it blew heat the whole time, didn't exceed 85 degrees C and not a drop of antifreeze coming out any time I stopped.

That skid plate (?) being removed is the only change I have made.

Is it possible that the mechanic topped the coolant too high and when it reached highway temps, it just blew the excess out? I know the reservoir is supposed to have something to say in that but I am grasping at straws. I suppose checking the coolant level as soon as it cools off would tell me that. I will do that but any other ideas are welcome.

Kent