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Pulled a dumb one yesterday. AC system was functioning, but only blowing cool air. Bought a recharge can with hose, hooked to low side but the system would not take much product out of the can. I could see the pressure change on the guage every time the compressor cycled.

It was suggested by someone to relieve some pressure from the valve and try again, so I did from both valves. I did not realize that the high side valve was designed differently than the low side. I pushed a small screw driver in there and damaged the high side valve.

I can see how the low side valve can be removed, but how do you replace the high side valve? Do you have to remove the whole hose assembly and go at it from the back side or is that not a serviceable item? Do I have to replace the entire hose/valve assembly? Its hot down here right now and I need to get this thing fixed asap, thanks in advance for any help.
 

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The valve core itself is replaceable, or replace the the whole fitting. It should unscrew from the manifold.
 

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The valve core itself is replaceable, or replace the the whole fitting. It should unscrew from the manifold.
I did not want to get heavy handed with the fitting, I see that it is a hex shape that you could put a wrench on, but the whole fitting looks to be welded in place. The guts are unlike the low pressure side which is similar to a shrade valve that you can just unscrew. How do you just replace the valve core?
 

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You might have to replace the manifold lines that go to the compressor.

If your system is similar to the one in mine, the High Pressure valve is not a swap like the low side is.
You would need to remove the hose lines going to the compressor and replace them.
And then do a vacuum and charge on your system.

BTW-- I used to live in Milton....
Miss the P.cola beaches. :(
 

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Discussion Starter #5
You might have to replace the manifold lines that go to the compressor.

If your system is similar to the one in mine, the High Pressure valve is not a swap like the low side is.
You would need to remove the hose lines going to the compressor and replace them.
And then do a vacuum and charge on your system.That is what I was afraid of, already checked out the hose assembly on rock auto, I was surprised to see that the whole assembly was only $50. Even though I hate to do it, I might just take it to the shop down the road and have them fix it.

BTW-- I used to live in Milton....
Miss the P.cola beaches. :(
I was just out on Johnson's beach yesterday after cruising around in the boat on the inner coastal.

---------- Post added at 11:55 AM ---------- Previous post was at 11:52 AM ----------

You might have to replace the manifold lines that go to the compressor.

If your system is similar to the one in mine, the High Pressure valve is not a swap like the low side is.
You would need to remove the hose lines going to the compressor and replace them.
And then do a vacuum and charge on your system.
That is what I was afraid of, already checked out the part on Rock Auto, I was surprised to see that the whole assembly was only $50. Even though I hate to do it, I might just take it to the shop down the road and have them fix it.
 

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Well I assume your system has been evacuated, so nothing in it.....

In which case, what I would do....might save you a bit of money.
Replace the manifold assy. hoses......
Then take it down, and just have them do a recharge on it.....

I would be curious to hear how much they charge you, but I would expect between $200 - $400...but I could be very wrong.

But if your lines are only $50, then that is pretty cheap.
The one on mine, I think was around $100
 

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I just ordered the hose in question AND the dryer/accumulator (silver can on the firewall) since its purpose is to help dry any moisture in the system (as well as a holding reservoir).

Parts cost me about $60 for the hose and like $15 for the dryer (plus shipping). Figure if I have to do one, I'll do both.

I have the same issue with mine....but that 'hi pressure stem' that fits INSIDE the 'hex head stem' that's welded on....they stripped the inside threads off, and they smashed the outside part with pliers or something. I had to replace the compressor and belt when the clutch locked up. Parts should be in this week (new headlights I ordered came in today :glasses: & I ordered it all at the same time).

Good luck on your repair. I have a friend with a vac pump so I'll prolly borrow it or swap it all at his place.
 

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ok...I dunno what this is or how it plays in the system.

Please explain...I'm still learning A/C systems...
 

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Its the 99 Tahoe.

I'm getting ready to change out the headlights before church...so I'll stick my head around there looking for the dimpled pipes.

I went on ebay and ordered one for less than $3 shipped :)
 

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I tried looking for a diagram for that model truck but couldn't find one....

Maybe get a Chilton's or Haynes manual, and see where the thing is located, but it is probably coming out of one of the condenser tubes.
 

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Well, when I had the grille off and was looking around, I found NO 'dimpled' locations, but the only place that looked feasible was the lower connection on the condenser out front. The length looks right and the angle kind of seems logical.

I didn't see anything in the manual I have (Haynes)...and online it only showed a pic for a rear a/c vehicle (which is just a different hi pressure hose with an extra fitting). Still didn't have dimples.

I have the dryer in hand today....no hose or tube yet.
 

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Actually I think the orfice is a metering device that has been used to replace the TXV that was orignally used on AC systems, it is used to meter the refrigerant into the evaporater. Good luck with the system, be sure to pull a deep vacuum and check your systems oil.
 

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Well, dude I ordered parts from sent one USPS, and one UPS. The UPS part (hose) got here today.

The orifice got here today as well, via USPS.

Post office has been ROCKIN lately :)

Anyways, I'll bug my buddy to use his vac pump this weekend. Family will be gone til Sunday afternoon :party:
 

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I hear a hissing sound when I take off the plastic cap on the high pressure side. I feel like that's not supposed to happen, and perhaps the gasket has failed? But I'm not sure because it doesn't look like a replaceable value like the low pressure side.

Sorry for reviving an old thread, but this came up while I was googling.

 

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The whole valve comes off at the nut. Not like the Shrader type. You can grab a combination wrench and unscrew it.
 
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