89 a/c low pressure line freezing up - CorvetteForum - Chevrolet Corvette Forum Discussion

Go Back   >
Log In 
Register FAQ Search Today's Posts Mark Forums Read Vendor Directory

C4 Tech/Performance
L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

89 a/c low pressure line freezing up

Reply
 
 
 
Thread Tools Search this Thread
Old 04-25-2011, 11:26 AM   #1
corvette95
CF Senior Member
Thread Starter
 
Member Since: Jul 1999
Location: Huntsville AL
Posts: 2,098
Thanks: 0
Thanked 0 Times in 0 Posts
Default 89 a/c low pressure line freezing up

My low side is freezing up. I did replace compressor couple months ago. Changed orifice tube and pulled a vacuum. What causes line freezing?
corvette95 is offline   Reply With Quote
Old 04-25-2011, 12:26 PM   #2
SunCr
CF Senior Member
 
Member Since: Dec 2000
Location: San Diego, Ca
Posts: 7,839
Thanks: 0
Thanked 1 Time in 1 Post
Default

Low Pressure Switch should open at 25 psi to prevent the ice (assuming it's still R12). It's either defective or needs to be adjusted. There's a screw between the terminals of the switch. Turn it clockwise to raise the cutoff threshold. To check it out, hook up your Manifold Gage set and put the a/c on Max. Pull the Blower Motor connector and the pressure should drop. Note the low side pressure when the compressor cycles off. Remove the Low Pressure harness from the switch and turn the screw a 1/2 turn and recheck. If it doesn't change anything, get a new one. Note: the new Switch may be set for R134 which is a 22.5 psi threshold. That's too low and it will have to be adjusted to 25 psi to prevent the icing.
SunCr is offline   Reply With Quote
Old 04-25-2011, 12:37 PM   #3
corvette95
CF Senior Member
Thread Starter
 
Member Since: Jul 1999
Location: Huntsville AL
Posts: 2,098
Thanks: 0
Thanked 0 Times in 0 Posts
Default

Its still r12. I will check the #'s and that switch and post findings! Thxs!
corvette95 is offline   Reply With Quote
Go Back   CorvetteForum - Chevrolet Corvette Forum Discussion >
Reload this Page
  • 89 a/c low pressure line freezing up
  •  
     
    Reply

    Related Topics
    Thread Thread Starter Forum Replies Last Post
    Servicing A/C that has R12 colter C4 Tech/Performance 44 07-30-2015 07:33 PM
    Is It True That If You Put Automatic Transmission Fluid In... Builderrick Off Topic 14 05-11-2014 01:01 AM
    freeze plug size LT1driver C3 Tech/Performance 2 04-04-2014 11:50 PM
    59 cove trim help freez C1 & C2 Corvettes 13 03-19-2008 12:32 PM
    Plasma TV in garage vette1963 Off Topic 16 01-04-2008 09:41 AM


    Tags
    ac, freeze, freezes, freezing, frosting, icing, line, lines, low, mobil, orifice, preesure, pressure, side, tube

    Thread Tools Search this Thread
    Search this Thread:

    Click for Advanced Search

    Posting Rules
    You may not post new threads
    You may not post replies
    You may not post attachments
    You may not edit your posts

    BB code is On
    Smilies are On
    [IMG] code is On
    HTML code is Off
    Trackbacks are Off
    Pingbacks are Off
    Refbacks are Off

    Forum Jump


    All times are GMT -4. The time now is 01:25 AM.