What is the purpose of having this hose in the cooling system? Can I use these ports for my coolant filter? Currently I have the filter running off a T in the heater core lines.

 

Thermostat Bypass hose

Used to bleed air past the thermostat when closed. Also allows slight coolant flow when thermostat is closed.

I guess you could put a filter there. Coolant would flow when the thermostat is closed and that should be good enough. The filter does not do much anyway. However it does have coolant treatment in it and that should still protect the engine just as good as if it was flowing all the time.

 

Ah, thanks for the info. I've always wondered that. I got the smallest filter with 4 units of DCA2. The filter is heating up right now so I assume there is coolant flowing through it, but I'm not sure how much. I don't know if the heater core (brand new) offers enough restriction to force coolant thru the 90 degree T to the filter. I might just take the filter out later on down the road, but I figure I'd let it clean up the cooling system a little since I replaced the heater core.

 

And that little darn hose is $50!!! Don't cut it..

 

Holly crap, $50!!! When I had to replace mine 2 yrs ago because of cracks in it, I thought I was getting screwed when I paid $28 + change from the dealer. I almost just made my own at the time with some 90 deg fittings and short sections of hose.

 

I just used a generic straight silicone hose way back when.Just loop it up and back down.No need to get fancy.although now I have the full Mr Bob's silicone hose kit

 

I picked one up at Napa....$50 must be from dealer...Napa charged me $12 and I thought that was too much...

 

Well I guess I should have grabbed the rail.. I got it through Frieghtliner/Cummins..

 

Cummings isnt always the cheapest place to find things.

 

I'm glad I went to NAPA. I replaced ALL hoses for not much more than $50.

 

So if I remove the bolt in the yellow circle, does the water pump push water out of that hole at all times (thermostat open and closed)? Or is that an inlet back to the water pump? Thanks.

 

That's a head bolt do not remove that bolt.

 

Ya.. Don't touch that one..

 

Oh haha.. Alright. Glad I asked. I was almost sure it went to the water pump. Is there any other water pump outlet (or inlet) port on the engine?

 

Follow the other coolant line that runs along the manifold. It goes down to the coolant inlet down on the side of the block.