Good morning all! I was hoping for some quick feedback from some experts here. I am replacing the water pump on my 2007 Tahoe. I have a friend/mechanic who did some maintenance work on it earlier this year and he pointed out that the pump was making a noise (a bearing going as he put it) and I should replace it. Knowing I am fairly handy (we both snowmobile), he suggested I could tackle the project. It is not leaking yet but I want to fix this before it goes once and for all. I understand the procedure as it is pretty straightforward...I just have a couple questions:
1. When I drain the coolant, can I simply put a catch basin under the truck and pull the three hoses at the bottom of the pump? Will this allow all the fluid to drain, even out of the radiator?
2. When filling it back up, do I need to flush the system or can I simply add a 50/50 mix of coolant and distilled water and bring the level back up to the appropriate level? He flushed and replaced the coolant for me about 24 months ago.

Any feedback or suggestions would be greatly appreciated. Thank you for reading this....
Best,
Dan

 

if the coolant has been flushed previously, just drain the system and refill.

since the coolant is not old, don't worry about the rad completely draining; the only time i would want the rad drained is if i was going to vacuum fill the system...which is the best way but you need a compressor and vacuum lift filling tool.
remove the clutch fan before you take the belt off. keep the fan upright when off the vehicle

 

When I do them I pull my hoses off at the old water pump and let it drain into a catch tub. (Don't open the petcock on the radiator to avoid breaking it or causing a leak that now involves a new radiator). Once you have things back together you will find you need to replace about 2 gallons of Dex-Cool. I suppose in a pinch you could filter the old fluid if your catch tub was clean when you started. But $30 for a couple gallons is cheap compared to what you are saving not paying a mechanic to do your labor.

Also be careful reinstalling the fan clutch back on to the new water pump. In the case of doing it on a van (same engine) it is hard to see if it threads onto the shaft properly. It may mis-align, go on part way and feel tight and feel right. Though it may not be and cause a vibration that can be wrongly interpreted as a rough idle.

If the fan/clutch is not threaded on properly the clutch and fan can fly off when the engine is revved. If you make this mistake and are lucky, only the plastic fan blade will get trashed. But in the flying off process it can take out the cowling, hoses, belts, radiator and end up costing big $.