Author Topic: 87 r10 a/c blows cold then warm  (Read 238 times)

Offline lehman368

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87 r10 a/c blows cold then warm
« on: July 10, 2018, 06:20:19 PM »
On my 87 a/c blows cold then after running for hour or so it will start warming up and seams the air flow through the vents slows down. When you shut it off it seams to drip a lot of condensation water.


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Offline bd

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Re: 87 r10 a/c blows cold then warm
« Reply #1 on: July 10, 2018, 06:38:41 PM »
The evaporator is freezing over.  What are the system pressures?
Rich
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In other words... if people learn by making mistakes, by now I should know just about everything!!
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Offline lehman368

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Re: 87 r10 a/c blows cold then warm
« Reply #2 on: July 10, 2018, 08:34:46 PM »
The evaporator is freezing over.  What are the system pressures?




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Offline lehman368

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Re: 87 r10 a/c blows cold then warm
« Reply #3 on: July 10, 2018, 08:37:54 PM »
The evaporator is freezing over.  What are the system pressures?
I don’t have a pressure regulator for a/c. If I can find one From a friend I will check. Upper and lower? What pressures should they read at? 


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Offline VileZambonie

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Re: 87 r10 a/c blows cold then warm
« Reply #4 on: July 11, 2018, 05:47:44 PM »
If you have access to the proper manifold gauge set, you can monitor your operating pressures and report them back. Has the system been retrofit? What refrigerant is in it?
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Offline lehman368

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Re: 87 r10 a/c blows cold then warm
« Reply #5 on: July 12, 2018, 12:45:23 AM »
If you have access to the proper manifold gauge set, you can monitor your operating pressures and report them back. Has the system been retrofit? What refrigerant is in it?
Yes it has been retrofitted before I bought it. It would blow cold last summer but really never drove it on longer than 45min trips. Now after working on the truck this past year. I have been driving it more and taking it on longer trips. Real Big headache last weekend on a 3and 1/2 hour trip in 90 + degree heat. Stoped cooling after about 50 mins.


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Offline lehman368

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87 r10 a/c blows cold then warm
« Reply #6 on: July 12, 2018, 12:47:44 AM »
If you have access to the proper manifold gauge set, you can monitor your operating pressures and report them back. Has the system been retrofit? What refrigerant is in it?
Yes it has been retrofitted before I bought it. It would blow cold last summer but really never drove it on longer than 45min trips. Now after working on the truck this past year. I have been driving it more and taking it on longer trips. Real Big headache last weekend on a 3and 1/2 hour trip in 90 + degree heat. Stoped cooling after about 50 mins.


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The new refrigerant I think. I have not been able to find any one the has proper gages yet. After it thaws out it cools the same. We stopped to eat, when I came back out to the truck there’s a big puddle under it 3x6 foot spot.


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« Last Edit: July 12, 2018, 01:06:43 AM by lehman368 »

Offline Rapid Roy

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Re: 87 r10 a/c blows cold then warm
« Reply #7 on: July 12, 2018, 06:12:29 AM »
Welcome to the site.
1974 Cheyenne 10 LWB 350/TH350/AC/4 BBL Quadrajet

Offline Irish_Alley

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Re: 87 r10 a/c blows cold then warm
« Reply #8 on: July 20, 2018, 11:40:12 PM »
welcome from maryland, low Freon can cause the core to freeze up but like vile said get a manifold gauge set and see what the readings are
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