Author Topic: 87 r10 a/c blows cold then warm  (Read 133 times)

Offline lehman368

  • Newbie
  • Posts: 5
  • Newbie
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.


Sent from my iPhone using Tapatalk

Online bd

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 4790
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
It's difficult to know just how much you don't know, until you know it....
In other words... if people learn by making mistakes, by now I should know just about everything!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline lehman368

  • Newbie
  • Posts: 5
  • Newbie
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?




Sent from my iPhone using Tapatalk

Offline lehman368

  • Newbie
  • Posts: 5
  • Newbie
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? 


Sent from my iPhone using Tapatalk

Offline VileZambonie

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 16839
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?
,                           ___ 
                         /  _ _ _\_
              ⌠¯¯¯¯¯'   [☼===☼]
              `()_);-;()_)--o--)_)

Offline lehman368

  • Newbie
  • Posts: 5
  • Newbie
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.


Sent from my iPhone using Tapatalk

Offline lehman368

  • Newbie
  • Posts: 5
  • Newbie
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.


Sent from my iPhone using Tapatalk
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.


Sent from my iPhone using Tapatalk
« Last Edit: July 12, 2018, 01:06:43 AM by lehman368 »

Online Rapid Roy

  • Frequent Member
  • **
  • Posts: 262
  • Euless, Texas
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