A/C Diagnostic help

[Mogman]

Chart

 

[Pstyckiewicz]

I’ll put some more R134A in. Got a new toggle switch today from Advanced Auto parts. It is pretty close to what was in there without spending $100 on an exact new one.

 

[Pstyckiewicz]

I looked at the water valve today looks like it’s working. Although the heater core still gets pretty hot.

 

[Pstyckiewicz]

Took out the water valve and replaced it with a normally open ball valve. Toggled to A/C on valve closes. Turn off/heat on valve automatically opens. Works great, no more hot water getting in while AC is on.

 

[thoner7]

Glad you found the bad switch, that was starting to look suspect, yes the valve is closed (powered) in AC mode, failure of this valve is very common, you can force it closed, many replace it with a manually controlled valve and just switch it depending on the season.
Yes there is a drain hose that connects to a nipple on the bottom of the evap unit, unfortunately these are sometimes broken off

Any advice on how to "force it closed" while I wait to swap it for a manual valve?

Noob question - how much coolant will leak out when I do eventually remove the valve for the manual style?

 

[REF]

Pop The servo out of the holder ( has 2 metal fingers holding it in place) push the unit forward to close the valve and snap it back into the holder in that forward position. That will hold the valve closed so you have AC . no coolant loss at all.

 

[thoner7]

Just to confirm I’m doing this right - the little C shaped piece turns the valve? Forward is AC and back is heat? My truck has heat but the C lever was mid way between open and closed.

The last pic is how I left it….AC??

thanks to everyone for your help

 

[REF]

When the servo heats up it extends out pushing the C forward to close the valve, as long as the C is pushed as far forward as it will go and you snap the servo back into the holder to hold forward pressure on the C you should be great.

 

[Tiwaz]

I am having the same problem (Hot air in the A/C vent) and my question is:
If you just unhook the servo from the "C" looking hook and push it forward and DO NOT hook the servo back, doesn't that close any flow of hot water into the heater and therefore into the A/C duct forever....?
(Or at least until you push the "C" thing back manually or hook the servo again)

 

[REF]

Yes, pop it out of the C push it forward and then snap back into the C to hold it forward.

 

[Tiwaz]

Yes, pop it out of the C push it forward and then snap back into the C to hold it forward.

But if I hook up the servo again, isn't that going to drag the "C" forward and backwards just like it should...?

 

[REF]

No the servo is bad and doesn't push out anymore to turn off the water. So pop it out of the clip, push it forward and snap the servo back into the holder in the forward position to hold the valve closed. If you decide you want heat pop the servo out of the holder pull it back and snap it back into the holder in it's original position.

 

[REF]

I am sorry I think the confusion is what I am calling the C, What I am calling the C is the black spring steel clip that holds the servo itself. I think you were calling the C the lever coming out of the valve. So you pop the servo out of its mount push the servo forward while its still connected to the valve, it will close the valve, Then pop the servo back into the mount and it will hold the valve closed.

Look at the body of the servo and you should see the black spring steel c clips that hold the silver body of the servo to its mount, that's where you want to be working.
hope this clears up the confusion.

 

[Tiwaz]

So based on this new picture/names: Shouldn't I just disconnect the Servo from the Valve Actuator, push the Valve Actuator forward and leave it like that....? If I reconnect the servo isn't that going to push/pull the Valve Actuator...? and if it does not, what is the purpose of re-hooking the Servo....?

 

[REF]

Thanks for the picture, That servo heats up and expands out the front pushing the valve closed slowly. The units I have seen fail stop pushing out and just sit in the retracted position. If your servo is still expanding when on and contracting when off, (Note: that it expands slowly and closes the valve slowly so if your engine is warm and you turn the AC on the front will blow hot for a while until the valve slowly closes.) But to answer your question, yes if you close the valve with the servo disconnected it will work.

 

[Tiwaz]

The Actuator is as forward as it goes now and i have been driving for 30 minutes and nothing, still warm air from the front vents. I have to say thoug that after 30 min it chills somewhat, definitely more than it does for the first 20 min but that is something that consistently happened even before disconnecting the servo

 

[mrfarb]

View attachment 946151

The Actuator is as forward as it goes now and i have been driving for 30 minutes and nothing, still warm air from the front vents. I have to say thoug that after 30 min it chills somewhat, definitely more than it does for the first 20 min but that is something that consistently happened even before disconnecting the servo

I tried this and had the same result. In the end I pulled it off and the rubber flapper seal inside was deteriorated and allowed hot water by regardless. Pull it off and replace it.

 

[Tiwaz]

or maybe just put this valve inline and shut the valve off.

 

[Mogman]

or maybe just put this valve inline and shut the valve off.

View attachment 946195

That is what most folks do.

 

[Tiwaz]

do you happen to know the tube diameter so I can buy some clamps...?