ok. what ever.
mine, "up side down" one. must be an exception then ...

 

Leave it then. Was just trying to help u out. Will still work but heat won`t work as good. Why u on here if u don`t want help. Look at any cherokee and u`ll c that u have it upside down.

 

oh, boy
ok, I thank you very much for "trying to help".

You've stated that the valve would work only "one way", and you were wrong. Now you say it will work but "heat won`t work as good" , and you are wrong again.
And this is all fine with me, btw...

As for your "question" why I am here - it's off topic really.
But if you really want to know, for what ever reason, I am here basically for two reasons:
1. To have conversations with other XJ owners about technical issues, so I hopefully ACTUALLY!!!! understand what "things" are, how things actually work, how to fix them etc...
2. To share my experiences (good ones and bad ones) with other XJ owners.

that's it.

/best regards

 

Just pop the hood of an Xj with the same radiator setup as we have and look to c how ther HCV is hooked up.

 

Interesting https://www.cherokeeforum.com/f2/hea...l-valve-32971/

 

ok, Cherokeefever ,
I have an "advice" for you too.
Take that valve out and take a real close look at it. Open it up too.
Then get yourself few cuts of rubber hoses and take it to your bathtub facility and do some "experiments". Run water through it, connect it in various ways, open/close valve, see how it works.
It's fun to do and you will get a chance to actually understand what it is and how it works.

have a good time having fun

/best regards

 

Geez! Dr Zee... You need to get this repair completed so we can have that Beer! I'm getting thirsty!
Mike

 

heh heh,
It was completed - page2 / post#25
I have no problems with the valve since then.
As I've mentioned, if it will fail again, I will drop a note. If I don't post an "update" - this would mean one of two: either the valve works fine and no leak, either I'm gone to the void with no trace (well, could be both...)

now,
BEEEEEEEEEEEEER!!!!! , please

************
p.s.
there are many posts and replies here that are just - unintended consequences....which is fine with me -

 

I would like to provide my unsolicited $.02:

1) The valve functions the same either upside-down or right side-up as long as you have in the ins connected to ins and the outs connected to outs.

2) If you install the valve upside-down, then where the 2 pieces of plastic are molded together is constantly exposed to the pressure of the cooling system (when the thermostat is open of course). If you install it right side-up, then the interface is only exposed to the pressure when the heater is on. I had one of these fail at the interface and it was installed upside-down. My replacement is now right side-up. We'll see if I get the same failure. Both valves were Mopar parts.

As a side note, I have mine installed on an '87 (a closed to open conversion), and I currently have a 16lb. radiator cap. Can one of you guys with this factory plumbing tell me what your radiator caps are rated for? I could very well have just over-pressured the heater control valve.

 

I have 16lb rad cap.
Also I may be wrong, but I think that coolant always "runs" to the heater valve (and through the core, when the valv is open) regardlessly of whether or not the t-stat is open. Correct me if I am wrong.
************
when you say: "If you install it right side-up, then the interface is only exposed to the pressure when the heater is on."
what do you mean by "interface"? What exactly "inteface" is? I am just trying to understand what do you mean exactly
This valve is really nothing more than plastic cylinder with four holes/fittings, call them 1,2,3 and 4. The "valve" inside is a metal plate, that either opens flow between 1&2 and 3&4, while blocking the flow between 2&3 and 1&4; either blocking flow between 1&2 and 3&4, while opens the flow between 2&3 and 1&4.
As I understand, The engineering challenge here is all about the "problem" that to turn that metal plate inside the "cylinder" from one state to the other by the vac. actuator outside the cylinder - you need another "hole" (the lever hole, that is).
So there you have it - you must have a hole and you must not let the coolant leak through that hole - that's a challenge

 

On mine, the portion of the valve where the vacuum actuator is contains what appears to be a junction between 2 molded pieces of plastic (where the one out-of-plane port connects to the other 3 in-plane ports). THAT is where mine leaked (not where the vacuum actuator goes through the plastic housing).

My intent was not so much to address your engineering challenge as it was to address the statements regarding the "upside down" installation. My point was:

A) There is an ideal up direction for valve installation.

&

B) Up-side down installation will have zero effect on the operation of the valve. The only potential problem with an upside-down installation is the constant exposure of the plastic joint to the cooling system pressure. If you aren't getting leaks there... then there is no problem. Me: I leaked from that joint, so for all future installations, I will be ensuring that the joint is only exposed to cooling system pressures when coolant is flowing through the heater core.

As for your seal packing upgrade: I think its $$$

Edit: Here is the part I am talking about (from a picture posted earlier in this thread)

 

Uh, thank you for explanation...I get what you are saying now. I was not sure before. It makes sense and maybe you 've got a point there.

The only thing I must add here is that , I would guess, that "the joint" should be able to handle the coolant pressure regardlessly and maybe it should be able to handle even somewhat higher pressure than "expected" to be there ...don't you think? I mean, say, you always have the heater "ON"....then what the difference? See what I mean. Or maybe there's a difference. Maybe I'm missing something.
One thing is clear though - the valve isn't symmetrical ..heh heh, so the designer must of think of something when he was designing it.

 

Agreed, and so should the seal for the actuator valve. Point is, those are both the weakest links and sources of leaks. The actuator hole you can't minimize the exposure to, however, "the joint" you can. Do I think it is worth the 2 minutes of your time to switch? No. But perhaps if you need to install another one again in the future, you can minimize your leak potential and put "the joint" at the bottom.

Again, the only reason that I even bring the subject up is because "the joint" is where I had a 1-year old Mopar heater control valve leak from.

 

The heater control valve in my jeep and is leaking coolant bad but im not sure where from I did a pressure test on the cooling system and it was leaking around the control valve so I replaced it and also cut the ends of the hoses off and put new clamps on them (the screw kind)...The heater control valve in my cherokee is upside down compared to the picture you have posted I would really appreciate any help I could get on this guys

 

are you saying that you've replaced the old valve with a new one and now the new one still leaking coolant?
Or is your question just about the "right" position of the valve.?
When you say: "The heater control valve in my cherokee is upside down compared to the picture you have posted" , which picture do you refer to?
Do you refer to the picture I've posted or to the picture posted by Cherokeefever?
I personally have no idea which way is "right". The way it is in mine jeep is the way it was as I've got it... I've replaced mine (the old valve that was leaking, that is) and installed the new one exactly the same way as it was... so if it's upside down, then someone before me installed it that way.
All I know is that it works either way.
***********
After I've installed the new valve it was still leaking through the lever hole, as described at the begining of the thread.
So....As for leaking valve issue - all described above still stands
I just can add this. As of today, since the last update (see post #34), I had no problem with the valve. Made it throught the winter and not a single drop ever since, bang-bang-bang ...