Water pump play/wobble

wormwood1978

Original poster
Member
Jan 3, 2015
75
2008 Trailblazer, 4.2. 105K.

How much if any play or wobble should there be with the water pump pulley? Should I look at replacing the water pump? Do I replace just the water pump or the pulley as well? Fan clutch is original, should I replace it as well since I'll have to pull it out to get to the water pump?

 

flyboy2610

Member
Aug 24, 2021
460
Lincoln, Ne.
Yep, she's all done! You shouldn't have to replace the pulley, though.
Replacing the fan clutch is a judgment call. A good one (AC/Delco) is kind of pricey, and if yours is working fine there's really no need. If you have any doubts about it, this would be a good time to do it though.
 

TollKeeper

Supporting Donor
Member
Dec 3, 2011
8,047
Brighton, CO
Since he has a 2008, isn't it going to be the old style thermal clutch? On those, if it ain't broke don't fix it!
 

flyboy2610

Member
Aug 24, 2021
460
Lincoln, Ne.
A tip for making it easier to change the water pump:
Remove two of the bolts (on opposing sides) holding the fan clutch to the fan blade. Replace them with 8mm X 40mm bolts, but only screw them in about 5mm or so. Then remove the other two fan clutch bolts. This will allow the fan clutch to slide forward far enough to make it easy to clear the water pump, but the bolts won't allow the fan clutch to drop out of the fan blade into the bottom of the radiator.
 

wormwood1978

Original poster
Member
Jan 3, 2015
75
I changed the water pump last week. It took a few hours but I'm a slow worker and did two flushes as well. I thought undoing the fan clutch nut would more difficult than it was. I did apply mouse milk twice beforehand and hit the nut with an air hammer. After that, attached a chain to the water pump to hold it in place and a wrench with moderate force on the nut turned it free. I replaced the water pump with an OE AcDelco pump.
 

2001ZR2

Member
Jul 16, 2019
93
Kansas
I just did the water pump and fan clutch on my son's TB. Wasn't too bad had enough time to do the demo yesterday and put it back together today.

That waterpump is done and had to pull the belt on my son's truck as it got stuck behind the water put pulley
 
  • Like
Reactions: Mooseman

Forum Statistics

Threads
23,273
Posts
637,499
Members
18,472
Latest member
MissCrutcher

Members Online