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1985 international truck air problem
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john510
New User
Jul 14, 2012, 4:15 PM
Post #1 of 7
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1985 international truck air problem
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OK here is what I am dealing with and maybe someone can give some insight on what to look for or what to do with this air conditioner system
Older 1985 International Truck, was a r-12 system that someone supposedly removed the older oil and changed over to newer R-134a
so here is what I did, when I started this the truck air conditioner compressor would cycle but no cold air, at one time there was cold air but that was last year.
Now to today, I removed the old rusted out receiver /dryer and replaced it with a new one and replaced 1 new line that was bad and rusted. Before installing the new line and receiver/ dryer I removed the lines off the compressor and flushed the condenser and and the evaporator with a flushing agent for air conditioner systems, the blew all lines out with air until nothing was coming out . installed the new line, receiver/dryer, new o rings, and re-installed the lines on the air conditioner pump with new o rings. then vacuumed the entire system, low and high side for 45 minutes. Watched it for 5 minutes after to insure it maintained negative pressure before starting to load it.
I started with a 6 oz can of ester oil and r-134a and noticed the pressure with the unit running shot right up low side 35 psi ,high side stayed low , pump would not engage. Added another 6 oz can of the ester oil with 134a and unit running but pump still would not engage, for some reason I was not getting power to the compressor unit? so I added 12 volt power to engage the pump manually while running to see if the unit would load any r-134a, the low side seemed as if it did not want to take the 134a, and noticed the pressure on the low side going to 80 lbs while the high side stayed all the way down to about 20 lbs?
What would stop the power from getting to the compressor ? why is the pressure not correct? what turns the pump power on and off? I didn't see a expansion valve or orifice tube where is that hiding and could these cause the problems? I dont knwo why it would cycle before I did this stuff? and ideas I m showing some pictures , may be I can get a little help, thanks
http://www.j7l.com/air/air001.jpg
http://www.j7l.com/air/air003.jpg
http://www.j7l.com/air/air006.jpg
http://www.j7l.com/air/air008.jpg
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Hammer Time
Ultimate Carjunky
/ Moderator
Jul 14, 2012, 4:34 PM
Post #2 of 7
(3465 views)
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Re: 1985 international truck air problem
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You have an expansion valve system and the valve will be at the evaporator.
There has to be something wrong with your gauges or hookup because if the compressor isn't running, the pressure has to be equal on both gauges. The 80PSI should be sufficient to engage the compressor if that is actually the pressure inside the system and not just at your gauge. Those York compressors used to have a backseat shutoff valve at each service port that had to be opened.
Here's what the shutoff valve looked like
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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.
(This post was edited by Hammer Time on Jul 14, 2012, 4:39 PM)
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john510
New User
Jul 14, 2012, 5:10 PM
Post #3 of 7
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Re: 1985 international truck air problem
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NO mine does not have a shut off valve like you show, but I will look under the dash at the firewall for a expansion valve, I didn't see anything outside for one sure it has one, and the gauge es are working fine, that's what bother me.. I want to see if the expansion valve is the problem I will have to locate it.
Funny how no power gets to the system I checked the wire at the compressor with a test light and no power with everything running?
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Hammer Time
Ultimate Carjunky
/ Moderator
Jul 14, 2012, 5:13 PM
Post #4 of 7
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Re: 1985 international truck air problem
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The expansion valve is not your problem and your gauges are not working right. As i stated, if you are not seeing the same pressure after 5 minutes, your gauges are wrong. It's all one storage tank when the compressor is not running.
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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.
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Discretesignals
Ultimate Carjunky
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Jul 14, 2012, 5:19 PM
Post #5 of 7
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Re: 1985 international truck air problem
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You must of had a fun time flushing the evaporator with the expansion valve in the way.
Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.
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Hammer Time
Ultimate Carjunky
/ Moderator
Jul 14, 2012, 6:31 PM
Post #7 of 7
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Re: 1985 international truck air problem
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It's nearly impossible to flush an evaporator to start with but it absolutely can't be done with an expansion valve in place. If you did force some fluid through the valve, it's likely still sitting in the evaporator which will be a big problem, depending what you used.
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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.
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