I am going to change the water pump on my 98 dak w/3.9
On the napa website they list a few some have pressed on pulley, some have bolt on, and then there is a severe duty pump that shows another cylindrical type gizmo with an additional gasket. Does anybody know what that thing is ? Is it a stock component ? Is it an upgrade ? Where does it go?
The price difference is about 35 dollars, I don't mind spending the money, i just don't want to be left with a spare part that is useless

 

Yours is probably just the regular water pump, not a severe duty. The new pump should come with the new pulley already installed. It's a good idea to remove the old pump and take it with you to the parts store and compare it to the new pump to be sure you get the right one. Be cautious and check the new pump very carefully if you buy a Napa pump:

https://dodgeforum.com/forum/2nd-gen...i-for-diy.html

I recommend the Duralast Pump from Autozone. They cost less, are made very well, have a lifetime warranty and are made here in the USA. The one I put on my truck a few months ago is doing great.

I am no water pump expert but I looked at the severe duty pump for your truck on the Napa website and I don't see any cylindrical gizmo. What I think you might be seeing is the threaded end where the fan clutch screws back on to the new water pump. Any water pump you buy should have that threaded end on the front of it. You need to remove the fan clutch from your old pump and put it on the new pump.

It's also a good idea to replace your bypass hose while you have the water pump removed, and replace the radiator hoses too if they are old or have a lot of wear. My radiator and bypass hoses were original and I had to cut them off to remove them, yours may be the same. Napa does have a good deal on the upper and lower hoses, the upper hose is sold as a complete assembly and even includes a new radiator cap.

Jimmy

 

Originally I planned on just changing hoses but I have leak and it makes the harmonic balance wet, according to the threads this is indicative of a water pump gasket. The truck has 137,000 on the clock so i figured if i am going thru all that trouble to change hoses and a gasket get the pump now and be done with it.

napa lists 2 severe duty pumps, the one that shows the gizmo is the one with the bolt on pulley. I think a bolt on, may be a little more durable than a pressed on pulley. Their standard duty pump with the bolt on pulley is $52 and the severe duty is like $89
there are no auto zone's locally we have napa and advance auto, around here

 

The small leak may be from the weep hole in the pump. When your bearings start to to bad, it allows the coolant to leak through those holes.

 

The GMB water pump from Advance looks to be good quality. I checked one out when I went through all the problems with that Napa pump. Do a Google search for Advance Auto Parts discount codes, buy online and apply the code and and you could save even more money.

Jimmy