Automotive Air Conditioning Information Forum (Archives)

Provided by www.ACkits.com

We've updated our forums!
Click here to visit the new forum

Archive Home

Search Auto AC Forum Archives

New to this, need help

tommyb50 on Wed July 18, 2012 8:14 AM User is offline

Year: 1997
Make: Volvo
Model: 850
Refrigerant Type: R134
Country of Origin: United States

Hi, need some basic help. Basic bungling do-it-your-selfer here. For a few years I have been putting in two cans of R134 every once in a while. Bought a simple gauge set at Advance and eventually got some cans in bulk at Sam's Club. Did fine and should have left well enough alone. Never really looked for the leak just topped the system up as needed. Then I got 'smart' and picked up a set of real gauges from From Harbor Freight and bought a 60 pound tank of refrigerant (figured this would last me for years). Well... now I can's seem get the system properly charged. I hook up the blue line to the low pressure input, open the gauges, open the can and it seems that not too much happens. The system stays right around 25 PSI. Shake the can a little and it pops up a bit and goes back down. When I was using the old system I usually got it to charge around 35 psi and the car cooled real well. I've read online stuff about pulling a vacuum and putting in 2 lbs of refrigerant but all of that means nothing to me.

What am I missing? All help is welcome. Especially a simple set of directions for how to use this new equipment (for real dummies) would be appreciated.

Thanks,

Tom

Cussboy on Wed July 18, 2012 10:39 AM User is offline

First: you have a leak which should be fixed.

Second: see above.

mk378 on Wed July 18, 2012 12:20 PM User is offline

Like the other guy said, find the leak first. Topping up a leaky system is costly and eventually you lose enough oil to cause problems.

You need a scale when using a big tank so you can keep track of how much has been put in. While charging by pressure (generally not recommended) it is more informative to watch the high side. When using a manifold gauge you have to close the charging valve wheel to see the actual pressure in the car.

tommyb50 on Wed July 18, 2012 2:37 PM User is offline

Quote
Originally posted by: mk378
Like the other guy said, find the leak first. Topping up a leaky system is costly and eventually you lose enough oil to cause problems.



You need a scale when using a big tank so you can keep track of how much has been put in. While charging by pressure (generally not recommended) it is more informative to watch the high side. When using a manifold gauge you have to close the charging valve wheel to see the actual pressure in the car.

First, thanks for responding!! This is helpful. I need a scale, should have guessed that. But what is the charging valve? I only connected the low side, so that was clearly an error. Am I supposed to put on both high and low side and close the connection going into the low side? Thanks again.

mk378 on Wed July 18, 2012 10:59 PM User is offline

Confirm both hand valves on the manifold are closed. Couple onto both high and low side. If there is pressure left in the car (not a total leak out), start up system and measure operating pressures.

To charge, connect refrigerant supply to the center (yellow) hose. Purge the air out of the hose by loosening the connection at the manifold while you crack open the valve on the cylinder. Then tighten the connection and open cylinder valve fully. Zero the scale. When you open the low side hand valve on the manifold, refrigerant will flow into the car. The scale will read negative readings according to the amount of refrigerant removed from the cylinder.

Never open the high side hand valve except to pull vacuum with the engine off.

Edited: Wed July 18, 2012 at 11:02 PM by mk378

tommyb50 on Mon July 23, 2012 8:56 PM User is offline

Quote
Originally posted by: mk378
Confirm both hand valves on the manifold are closed. Couple onto both high and low side. If there is pressure left in the car (not a total leak out), start up system and measure operating pressures.



To charge, connect refrigerant supply to the center (yellow) hose. Purge the air out of the hose by loosening the connection at the manifold while you crack open the valve on the cylinder. Then tighten the connection and open cylinder valve fully. Zero the scale. When you open the low side hand valve on the manifold, refrigerant will flow into the car. The scale will read negative readings according to the amount of refrigerant removed from the cylinder.



Never open the high side hand valve except to pull vacuum with the engine off.

tommyb50 on Mon July 23, 2012 8:59 PM User is offline

Quote
Originally posted by: tommyb50
Quote
Originally posted by: mk378
Confirm both hand valves on the manifold are closed. Couple onto both high and low side. If there is pressure left in the car (not a total leak out), start up system and measure operating pressures.



To charge, connect refrigerant supply to the center (yellow) hose. Purge the air out of the hose by loosening the connection at the manifold while you crack open the valve on the cylinder. Then tighten the connection and open cylinder valve fully. Zero the scale. When you open the low side hand valve on the manifold, refrigerant will flow into the car. The scale will read negative readings according to the amount of refrigerant removed from the cylinder.





Never open the high side hand valve except to pull vacuum with the engine off.


I have to think this through some, this is all new to me. I am even dumber than I seem, but I think I'm getting the idea.

joe_mn on Tue July 24, 2012 8:44 AM User is offline

you bought a #30 cylinder for future use? wow, either you have a huge leak or dozens of cars. i am in favor of learning new skills and understanding how a/c works is good but usually the car is fixed and never needs additional service. you usually forget what little you learn in a year or two. too be constantly working on a/c means something is wrong with car. i shop at sams and have never seen #30 tanks of freon? is it next to the gas grills or trampolines?

chuckwp on Tue July 24, 2012 7:29 PM User is offline

Quote
Originally posted by: joe_mn
you bought a #30 cylinder for future use? wow, either you have a huge leak or dozens of cars. i am in favor of learning new skills and understanding how a/c works is good but usually the car is fixed and never needs additional service. you usually forget what little you learn in a year or two. too be constantly working on a/c means something is wrong with car. i shop at sams and have never seen #30 tanks of freon? is it next to the gas grills or trampolines?

Sams used to sell R134 in 30# cylinders. Not sure if they still do. Haven't sold freon (R12) for a long time. I bet a 30# cylinder of freon would be well over a grand these days, if you cold find one.

fonebone on Sat July 28, 2012 12:26 AM User is offline

Hi Joe-mn-- You read the first post too fast- He said he bought a 60 pound!!!! container. That's really ready for any leak!

fonebone on Sat July 28, 2012 12:40 AM User is offline

Hi Tommyb50- Go to tips and FAQ's at the main page to A/c forums-lots of good help there. One very important point when using gages. Hook them both up, but do NOT open hi side-leave it closed. It will give you readings when closed, but keeps the compressor from pumping pressure back up through the line and over pressuring (as in exploding) the tank! Remember that and take it from there. Unsure of something? Keep asking! We were all new to this at one time.

Edited: Sat July 28, 2012 at 3:15 PM by fonebone

Back to Automotive Air Conditioning Forum

We've updated our forums!
Click here to visit the new forum

Archive Home

Copyright © 2016 Arizona Mobile Air Inc.