Is the cold a/c mod bad for the heater core??
 

I searched for this mod and all the threads seem to be pretty old. I remember reading awhile back that the heater core bypass mod could be bad for the heater core because the coolant isn't running through it can cause it to leak? Anyone have any problems with this mod? would like to do this cause its getting hot in florida.... Can anyone suggest a simple way to do the mod, i don't need to run off vacum lines and electric switches, i was thinking of just using a couple of ball valves if thats possible. Was hoping to be able to run it in regular a/c as well and not just max a/c.

So long as you periodically let coolant flow through the heater core, I don't see the harm in it. I'm no expert either, so take what I say with a grain of salt. Hopefully one of the gurus will chime in.

I don't think so either and the salt applies to me too. I don't hold any certifications or degrees other than turning wrenches on my 7.3L for a decade now (where does the time and all my money go?). I have had 2 Ranger valves (both leaked) and I recently put a ball valve in the heater supply line (or maybe it's the return). I only shut it when I know it's going to be hot that day. I've not had it long and have yet to shut it for more than a couple of days at a time.

IMHO if you open it every now and then to circulate coolant so it does not become stagnant it shouldn't be a big deal. The truck isn't running but people let these things sit for months at a time with no issue.

Just my .02

did mine with the ranger valve eight years ago no problems orig heater core 373k on motor. very good fix cause it allows cool fresh air inside when in vent mode . and it really drops the temp on max ac.

I had the Diesel Site MAX A/C valve and that was a piece of crap that didn't work right from day 1.

I installed the Ranger/Excursion valve and it has been good since.

My third and final option if the Ranger valve fails will be the manual ball valve handle. Although, I like not having to open the hood to get max A/C.

In addition to this mod, you may want to clean the evaporator, which is free minus the time invested.

I wouldn't block both the inlet and outlet, that could cause pressure issues inside the core and blocking both will do nothing more for it than just blocking one. Open it once a month or so with the engine running to 'flush' it. Probably not needed, but I'd feel better doing it than not.

are you saying to just put a ball valve on the inlet? i thought i had to install a bypass hose from inlet over to the outlet line to keep it circulating but just bypassing the heater core? just cutting in one ball valve would be great, just don't see how to keep the coolant flowing

I had nothing but leaks while using the NON OEM Ranger valves. I installed an OEM Ranger valve and have had no issues for the last year or so.

As you know the Ranger valve is vacuum activated so if you start your truck prior to the vacuum pump building enough negative pressure (vacuum) to close the valve, which is not a problem in the hotter climates due to not needing to allow the glow plugs to heat, then, there is regular circulation for about 10-30 seconds after each start.

As to the ball valve, I was told to incorporate a physical bypass: think two "T's" with a short hose between, after the coolant leaves the engine and prior to the valve so that coolant could flow/return to the engine and not dead head.

The flip side of this argument is that provision does not exist on any of the factory equipped Excursion valves on Excursions that I've seen...single hose in and out of the valve....OEM Excursion valves effectively dead head for the most part.

Duplicate post......ARG!

If you go the ball valve route, you could simply leave the valve mostly closed but partially open to address the stagnant coolant concern.

Sorry to hijack this thread but whats the part numbers for the upper radiator air deflector and the side radiator deflectors? I need them but cant find exactly what im looking for.
Truck is 00 f250

https://cimg1.ibsrv.net/gimg/www.for...7534e0c59e.jpg
and why must everyone over complicate things? yes its vac opperated but no dead head here....this was a ranger/excursion valve BTW....just sayin' ;)

For clarification, actually, the above picture represents the Ranger valve which does not dead head the coolant flow prior to the heater core and does provide a return path from the head to the water pump which is why it is preferred by many.
Below is the Excursion valve which does dead head coolant flow to the heater core which is a concern for some but evidently not for FORD....hence, some installing a ball valve only. Each person has to make their own decision on their own truck at the end of the day and live with the results be they positive or negative, real or perceived. IIRC, both have a small hole that allows a very small amount of coolant to flow which would be insignificant as to cooling for the engine. The ball valve, if fully closed, would not allow for this.

Any of these approaches leads to much cooler air in the A/C vents.
https://cimg2.ibsrv.net/gimg/www.for...ed5f98c413.jpg

Again, I had the Diesel Site version of the dead head valve (hated it, never worked right from day one) and removed it for the bypass or Ranger version. My A/C cooling is significantly cooler this year from last year since cleaning the evaporator and installing the Ranger Valve. I saw moderate decreases in A/C cooling after the evaporator cleaning, but the real show stopper was the Diesel Site valve coming out (dead head) and the Ranger valve going in.

Done, I am very happy with my A/C now and that was driving through Florida humidity this past weekend.

well i wish i would have waited a little longer, i put in the ball valve last night.... did the dieselsite version not work because it didn't cut the flow completely off, or that there was not a continuous bypass loop for the coolant? in logic i would think the ball valve would work unless it would allow the hot coolant to back feed up the return line somehow