'05 GMC 5.3L Water Pump

[fatfords]

Hey folks,
I haven't been around much lately since I sold my "parts chaser", but I need help with my '05 GMC and I know where all the smart folks hang out!

A few days ago my truck leaked a bit of anti-freeze in the garage. Turns out its the water pump (61k miles) so I bought the parts and had a couple of hours last night to change it over. I spent most of that time trying to figure out how to drain the radiator. There is no drain plug on the lower driver's side like the Haynes manual shows. It looks like there is a casting for it along with a nipple to hook a drain hose to, but no valve or hose. Stopped at the dealer this morning to get the steering shaft replaced and confirmed with the parts guy that some radiators didn't have a drain valve!?!

It looks like my best option is to remove the lower hose on the passenger side and try to catch as much of the mess that spills out as possible. Anyone ever done this on one of these radiators or have any better ideas?

thanks,
Kent

[496stroker1]

yep, whenever i need to drain the rad thats usually what i do is just pull the lower hose off and let er fly. probably why they stopped puttin a drain on the rad. can get kinda messy maybe do it outside

[fatfords]

That's what I did last night. Not too bad. I used a large flat plastic box and caught most of the mess. The good part was it only took about 3 seconds to drain the radiator! Hope this aftermarket water pump lasts longer than the GM one.
Thanks1

[DirtyLarry]

Did you find the water pump was actually leaking or just the gaskets? The Gen III’s have a bad habit of leaking coolant from the water pump gaskets. I have seen a lot of good water pumps tossed into the trash because of $15 leaking gaskets (in warranty and out of warranty jobs). Most people do not even realize it because they change the gaskets when they swap the pump…as far as they are concerned the leak stopped when they replaced the pump.

[89 crew]

The reason they got rid of the drain valve is because in the plastic tanks it doesn't work right! very often when you try to open the valve it strips the threads, and you then have to fix that too. drop the hose and mop up what you don't catch.

[Huck]

I had a leak on my 99' with 140,000 miles on it so I used some stop leak. sold it with 185,000 with no leak. cost me about $3. and 15 minutes.

[Waylon]

My '04 Z71 started leaking, so I looked around on the internet and found out it is usually the gaskets that leak so I changed the gaskets and got it all put together and filled it back up. It started leaking again, after a better search I saw it was actually leaking out of the little seep hole in the pump. So I had to get a new pump and do it all over.

[Pyrotechnic]

My dad had the gaskets go bad on his 2002. The pump was perfectly fine, but it had 60,000 miles on it so he went and got a new AC Delco pump. It came with updated gaskets. Also came with a new 186 degree thermostat and a new thermostat housing. The thermostat and housing seem to be a revised design for better sealing.

One of my dads friends has a Z71 that had a bad pump and he installed a parts store "lifetime warranty" pump. About 30,000 miles later he was taking it off and replacing it again because the shaft bearing wore out. The bearing just wore really quickly. He replaced it with an AC Delco replacement.

[WLPTMP]

its mostly the gaskets gone bad we do a lot of them

[Eyegore]

I just found a leak on my 2003 tahoe w/ the 5.3, looks as if it is the pump. My question, on a scale of 1-10, 10 being worst case, how hard a job is it to replace the water pump?