Help with cab coolant heater & coolant filter install for M35A2

[tcruwithme]

In the summer of 2014, I relocated my coolant cab heater into the cab under the map compartment in my A2 like they have them in the A3 trucks. Here are a couple of pictures of what that looks like: Picture #2 is where the lines come into the cab, from inside the cab. Picture #2 is where the lines go into the cab, from the engine side.



Later that same summer, I installed a Cummins Fleetguard heavy-duty coolant filter housing, bracket, and filter above the passenger side headlight. I have the coolant coming out of the top of the block and going into the coolant filter. It comes out of the coolant filter and goes back to the heater in the cab. It then returns to the bottom of the block. I've driven the truck a few times for a couple hours at a time, and the silicon heater hoses are doing fine where there are. Here are a couple of pictures of what that looks like:



I didn't drive my truck during the winter of 2015-2015, but I have driven it a couple times this December. I noticed that even when the truck warms up, the heater doesn't heat. The fan works fine (both high and low), but there is no heat output. My first thought is to bypass the coolant filter next weekend and take the truck for a drive. I wonder if the coolant filter introduces too much resistance against the flow of coolant fluid. Here's where I could use your experience and opinions.

I think I am using the correct ports on the block for the heater, but if you can confirm, that would be great.

If I can't put a coolant filter in series with the cab heater, where else can I plum the coolant heater into the system?

I'm not sure if I even know the right questions to ask here, so any thoughts you would like to share are greatly appreciated.

Thanks for your help.

 

[sandcobra164]

In picture number 5, the top hose is located above the thermostat. Remove the pipe plug just adjacent to the valve and plumb it below the thermostat. I wish I was a better searcher, there was a PS article that discussed this exact issue. Maybe Clinto or Doghead will come along, they do a great job linking stuff together.

 

[tcruwithme]

PS #461 Coolant Heater Instructions

Thanks for your quick response. Attached is the photo I found here on SS for the PS article that talked about this. It looks like I got the correct port, but I'm not sure ...

In picture number 5, the top hose is located above the thermostat. Remove the pipe plug just adjacent to the valve and plumb it below the thermostat. I wish I was a better searcher, there was a PS article that discussed this exact issue. Maybe Clinto or Doghead will come along, they do a great job linking stuff together.

 

[gimpyrobb]

Air trapped in the heater? They have a bleed screw for this issue.

 

[Jeepsinker]

Yes you have the correct ports. There is a very small metered orifice in the coolant filter base that doesn't allow much flow. That may be your problem. I have mine run separately. Hard to explain how, better with pics. I'll try later, but I feel awful lazy today...

 

[tcruwithme]

Sometimes the SS search doesn't do as well as Google. I did a Google search of SS and found a couple other threads. Bjorn from Crane Truck had success with a similar system, but he treated the filter as a bypass instead of running it inline with the heater. Here are a couple of the photos he posted in a different thread, and I'll rework mine like this next weekend. Thanks for your input everyone.