I see what you're saying. It's just an 'additional' flow path for the coolant return once the thermostat is open. To me it would be better for the port was located at the rear of the block where it can do the most good. Like the bypass kits. In its present location I don't see much in helping with cylinder 5 and 6. For some reason I don't remember the older 12v even having this??

I'll go back and study this more.

MikeyB

 

Cummins has supplied bypass kits to increase coolant flow for this issue for quite awhile. I believe some of the earlier setups used a freeze plug on the backside of the block. Later ones for the 24v's simply tap an addition plug out of the head. Lots of reasons to increase coolant flow. I can not think of any good reason to reduce it.

 

UPDATE --

Leak located under dash. Had the dryer and evap. reaplaced. Was over 1/3 low on freon. Techs showed me the old evap and the place where the red dye was leaking from. Blowing colder now, BUT still a little warmer on the passenger side, but much better than it was... 1300.00 for the repair.

 

I believe i have the same leak. . . NOT LOOKING forward to footing that bill, I do not have that kinda coin

Come on after market warranty. . . .

 

yes. Dodge wanted a lot more -- checked three dealers... also, this is under warranty now for a year... so, better than expected... glad to make some progress...

 

I run a ball valve on my 96 jeep. Without it you'll get cooked out of the thing. Also makes the AC work MUCH better.

I've read through this thread and the one thing I've not seen mentioned is the fact that it's a valve being installed, not an on off switch. :-) You can crack open the valve slightly and regulate the core temp. Having a very slow flow of water through the core will still allow you to regulate the AC temp with the controls. This way there can be warm water in the core, instead of hot, and regulated by the valve and air moving through it. Works great in the Jeep with the digital climate controls. No hot water at all and it displays errors.

Just a thought

I recently purchased my 06 3500 (only 11.9k on it :-) ) and in south Florida i'm having the passenger side blows warmer problem. I'm going to do the valve mod once again. But I'll prolly run it cracked open a bit.

Den

 

Yep. That's to address the stagnant coolant/high pressure issue on the #6. Opie and Wicked Diesel has a kit that taps the rear most coolant port on the head (which Dodge should have used for the heater port). The 600's are prone to blowing out the rear freeze plug. Even when stock.

MikeyB

 

That's the same port my coolant bypass filter taps:

http://stuff.is-a-geek.net/PhotoAlbu...ics/CRD_30.JPG
http://stuff.is-a-geek.net/PhotoAlbu...ics/CRD_31.JPG

I am hoping 2 ports out the back of the head is enough to avert any coolant flow issues that might affect the rearmost cylinders. Which plug the coolant comes from is secondary to the requirement to maximize flow in the rear portion of the engine. I will be reinstalling the stock heater fitting on the head at my next opportunity.

 

So I was doing a little searching on the net and came across a tech article for a similar setup on a Ford that use this heater control valve from NAPA.

It's a vacuum operated valve with a built-in bypass. In the article, they were tapping into the vacuum used to operate the recirculation door to close the valve. So if you went into the Max A/C position, the valve closed when the door opened.

Might be a possibility for automating this so you don't have to open/close valves as well as getting a single part that includes the bypass.

 

That sounds like an excellent idea. You should post a part# or fix the link.

 

Oops...didn't realize that my link was tied to a catalog session.

The NAPA part number is: BK 6601294
NAPA BK 6601294

And here is a link to the tech article from dieselwarden.net.
Tech Article

 

Cool find Aggie.

We have to figure a way of manually controlling the valve due to the lack of vacuum switches on our trucks.

MikeyB

 

I was looking for a similar valve that had a manual control, but couldn't find one.

My other options were:

1) Tie into the vacuum line that controls the Recirc door so that when the door opens, the valve closes. This would cut off the heater core whenever you were on Max A/C.

2) Find another vacuum solenoid like I use for my 2WD Low setup. An electric solenoid to control vacuum to the valve, then I can just tie into the main vacuum line and use a switch to control when the valve is open and when it is closed.

3) Just tie into the vacuum line directly during the summer so the valve closes whenever the truck is running. In the winter, just pull the line and cap everything so it stays open. This would be easiest to hook up, just more work to switch over when you wanted to change.

 

Wasn't there an electronically controlled valve available somewhere at some point in time? Is it possible to get one of these and just wire in a toggle switch in the cab?

Oh and my ac mod has been done for 6months now, absolutely loving it, don't know how cold it gets but we added a can and a half for the first time awhile back and that in conjunction with the mod has really got it blowing cold. Even now that its 105* here my ac still kicks butt. Only thing that bothers me is when I engage my ac after a cold start (general every morning first start) the clutch kicks in very noisily, almost like its catching something. After that I never hear it.

 

You don't have to do all of this to get your A/C to work like a champ. Just get a condenser fan and relay. Problem solved. It also quits boiling out the R134 due to excessive high pressures on the high side.