I believe I have to replace the v water pump, Cummins 435 water leaking out fast

Possibly possibly just the cold weather. I see you from Indiana so it gets cold there...? Seems like as soon as the cold comes on the o-ring that is at the back of the pump housing shrinks and you can lose a solid jug of coolant or two by morning..



that plastic ring thing goes on the back of the pump housing.. and the big o-ring wraps around it. And they tend to leak in cold weather only once the truck has cooled off.

 

Chances are the water pump is toast. Usually the bearings fail and it just pukes out the weep hole on the front when the truck's off. I've changed a few on ISC's (I think the ISX is similar, been a very long time since I've looked at an ISX though). If you can, take the belt off and give the pulley a wiggle side to side. If it has slop in it, the pump is toast for sure. If you can confirm its coming from the weep hole/pulley area of the pump, the seal inside has failed.

Its a pretty easy job to change out in most cases. Drain coolant, take the belt off. IIRC there are 3 bolts holding it to the block. Take the bolts out and the pump should pop right out. Just clean up the mounting face on the engine and install the new pump with a new o-ring. Belt on and fill up the coolant.

 

I'm not exactly 100% certain the ISX and ISC water pumps are the same/similar replacement procedure. Like I said its been a couple years since I've touched an ISX.

Edit: Just googled a picture of an ISX water pump. Quite a bit different than an ISC. More bolts and looks like it uses a gasket since its a different shape than the ISC. What I posted above in regards to replacing it may not apply.

 

It doesn't unfortunately. The ISX water pump is jack-the-bear to replace. There's an o-ring on the pump and three more on the housing behind it.

To verify where the leak is, climb up where you can look straight down between the housing and the block. If there's coolant there its a housing o-ring. Its probably better to replace the housing o-rings when you do the pump and you might have to unbolt the housing anyway. One of the water pump bolts is behind the crank dampener and its simpler to pull that than fight with it.

Frank

 

You won't need to remove the hood and radiator. You might want to check out @TruckerPete1990 here on TTR in the Mercer thread. He recently replaced his and might be able to give you some tips.

Frank

 

I attached instructions from Quickserve. Like others have stated, they one behind the damper is a pain to get to. On the other hand, the damper can be a pain to get off too! If you have to pry on damper, might as well replace. Has a dowel in it, so much sure you line it up if you do pull it off. Have taken them off that the dowel was shoved in crank. Makes an overhead a head scratcher. Being a 2006, yours should be a CM870. Go ahead a get some beer for this job!

 

I think TA will do it for like $500. And they probably have beer in the store.