Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum banner

1 - 9 of 9 Posts

·
Registered
2004 chevy trailblazer_ls
Joined
·
207 Posts
Discussion Starter #1
So I replaced the water pump in my truck today and was looking around and couldn't find any torque specs for the water pump. But in the process I found more then one person has broken a bolt off into the block. Roadie gave me the info so I thought Id share.

fan clutch to fan ---- 20 lb/ft
pulley to water pump -----18 lb/ft
water pump to block -------89 lb/IN<---take note of the IN thats inch not foot very very low!!!

If any body else can think of a torque spec that might be over looked post it up. Lug nuts, throttle body ect. (we all clean them, but they dont do any good if there so loose air is passing behind the butterflies or you strip the bolts so it can never be cleaned again.... :duh:)

With all the aluminum on are trucks you should be very careful as to how much to torque stuff. The old 2 grunts doesn't work to good anymore:bonk:
 

·
Registered
2005 isuzu ascender
Joined
·
319 Posts
No certain order. There are 5 bolts. Just start by hand so no crossthreading.

I'd hand tighten then torque using a star pattern like your lug nuts on tire.
 

·
Registered
2002 gmc envoy_sle
Joined
·
2 Posts
Torque for clutch nut...

Just to add FYI, the generalized instructions that came with my radiator fan clutch (HAYDEN 3200 Electronic - Viscous EV Fan Clutch Operation, ~$123) specified 37-45 ft-lbs for the clutch nut on the water pump shaft.

Although, I have yet to figure out how measure this when tightening the fan clutch nut during reassembly....is there a special technique or tool--I am only familiar with torque wrenches which use sockets. :-/
 

·
Registered
2004 chevy trailblazer_ls
Joined
·
77 Posts
A trustful mechanic told me it'll tighten itself on, so to just bump it a few times with the special pneumatic tool he let me borrow. :cool: https://www.amazon.com/Lisle-LI43300-Pneumatic-Clutch-Wrench/dp/B000JFJLTC

FYI I just installed a new fan clutch, water pump, thermostat, and hoses. Now it gets up to temp quick without the jet engine startup. Took seconds to get the fan clutch off and forever to get the fan shroud on/off.
 

·
Registered
2002 gmc envoy_sle
Joined
·
2 Posts
A trustful mechanic told me it'll tighten itself on
That's what I thought, but the instructions claimed "Proper torque is critical to avoid the fan clutch from detaching from the water pump when the engine is turned off.", so I just did the best I could by hand with a thin (cone/ tappet) wrench.

just bump it a few times with the special pneumatic tool he let me borrow
I bought that exact set for the removal process...worked great in the tight quarters...best to leave the serpentine belt on, though. :bonk: I didn't think to use it for the installation. I'll go back and do that, thank you!
 

·
Registered
2009 gmc envoy_slt
Joined
·
153 Posts
Thanks for the torque numbers. I changed my water pump today at 140K (no leaks yet but the drain on the WP was grubby) and it was good getting those numbers. You are right - the 89 In lbs is very little and it is tempting to over tighten - and no leaks either!
I had a b!tch of a time getting the fan clutch spun back on the new water pump and did a bit of cross threading! Fortunately I didn't have it too far on and was able to clean up the threads on the fan clutch with my dremel and with a bit of fussing, was able to get it aligned and threaded back on successfully. I used the old wp to help clean up the threads on the fan clutch. Again as suggested above - this is something that should be gently hand installed so you know the threads are correct before tightening it up. My Envoy is a 2009 with no electric fan clutch - it seems to be only a thermal type. Was still a bugger getting all that stuff off though.
 
1 - 9 of 9 Posts
Top