1999 QX4 Replaced radiator and now water pump leak?

[txg37x]

The QX4 started overheating. I checked the coolant and it was brown and pasty rust. I've had this problem on another car and got hosed by the mechanic, so I decided to try and take care of it myself. I flushed the system and things were great for a few days. Then the radiator started leaking, which I hadn't seen it do before. First it leaked from the bottom of the radiator, stopped for a few days and then leaked again from the top. I assume it started leaking because the system was now clear of gunk, so fluid was able to leak out. Because of this, I replaced the radiator and things were perfect for about two weeks. Now, yesterday, I've noticed a massive leak from right around the drive pulley. I assume this is the waterpump since it is located just above and to the right...?

Why would the waterpump just now start leaking? Same assumed problem, free of gunk, so now able to leak?

I try to save $ and do things myself, but from what I've seen, it looks like a tough job to replace the waterpump, and if I do replace the waterpump, I should replace the drive belt and a series of other things? Does this sound right? If I take it to a shop, what should I expect them to suggest and most importantly charge?

[Slumpert]

The waterpump has a built in weep hole. Using a inspection mirror it is possible to see if that is where your leaking from. At a minimum you should also replace the thermostat. Consider not only replacing the hoses but also the thermostat cover piece. Mine was so badly corroded it looked like the hose might just break off. It is like $15 part.

If you do replace the timing belt consider replacing.the crossover hose that is buried behind the timing belt back plate. That little hose was the hardest part of doing the whole job for me.

[Chuck Tribolet]

After you flushed the cooling system, what did you refill with?

Chuck

[txg37x]

Thanks slumpert, I'll definitely be replacing the thermostat while it's all broken down. I believe I know which hose you're referring too, and it is old and brittle, so it will need replacing.

Chuck, I flushed the system with radiator cleaner a total of three times and refilled with the standard 50/50 premixed coolant.

I called a couple shops and have gotten quotes from $500-700, but that's just for water pump and timing belt @ 4 hours of labor. I believe I should also be replacing what slumpert suggested and even the tensioner pulley and cam seals? I'm afraid the cost will be driven up. Does anyone have a DIY on all this? I don't mind an afternoon of work if it doesn't require speical tools or skill set.