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Fun Size Too · 06-04-2023, 08:34 AM

Hello everyone.
I have a 2004 Tropical and I needed to change a damage AC line. I now need to know how much the freon to charge the system. Can anyone help me?
I have exhausted all local AC service centers and all of National RV centers.

shootist · 06-04-2023, 08:52 AM

Change the line quickly, the least amount of time the system is open the better. If you feel the need to dry out the dryer (not a bad idea when a line has ruptured and been open) do your pull down for the leak check then turn the vacuum pump back on for several hours. Hot days are better or a heat gun on the dryer. You want all the moisture boiled out of the system.
As far as fill amounts, keep the condenser cooled with a spray nozzle on your garden hose and watch your gauges. Without cooling the condenser you'll get false readings on the high side. Assuming you have an r134 system just google the charts for the pressures to match your current weather.

https://www.google.com/search?q=r134...ri&safe=active

https://jamcoautoparts.com/systempre...shootingchart/

I know it's not the simple answer you were looking for but it's
The way it's done when you don't have fill amounts and/or there's problems

RichKimball · 06-04-2023, 10:35 AM

Quote:

Originally Posted by Fun Size Too

Hello everyone.
I have a 2004 Tropical and I needed to change a damage AC line. I now need to know how much the freon to charge the system. Can anyone help me?
I have exhausted all local AC service centers and all of National RV centers.

My Freightliner takes 3.5#. I grabbed this document once. It may help you or maybe not. Sorry if not. Good luck. Uses gauges you should be able to figure out and not overcharge.

2004Horizon · 06-04-2023, 10:58 AM

Look on your firewall for a sticker that will state how many lbs of 134a to use. (I added another 4 oz for extra life between re-charges. Do NOT add more!)

If you open your lines for even a second, you need to vacuum them out before you recharge. I hear Auto Zone or Napa will loan you a vacuum pump for free, but if this is not the case you can buy one at Harbor Freight for ~$90 I think.

The other purpose of vacuuming your lines is so you can verify you don't have any leaks after letting your system rest for 12+ hours. (24+ hours is better.)

Definitely replace your receiver-dryer. It's cheap. I also think it's a good idea to replace your TxV if you can get to it easily.

And definitely use Electric Contact Cleaner spray on any relay or connector to your AC system sensors. These things are usually visible on the firewall and then to rust.

When it comes to dealing with your oil in the lines that's a bit more tricky. If your oil is brown that's another problem you need to consider.

Note: My receiver-dryer had stuck check valves and cleaning these made all the difference in the world! Good luck.

Fun Size Too · 06-06-2023, 06:20 PM

Thanks everyone for your help

10EC · 06-12-2023, 07:19 AM

Quote:

Originally Posted by Fun Size Too

Thanks everyone for your help

What finally worked for me--- while system is open,
change the dryer,

vac the system,

throw the guages away,
scale in 3 1/2 lb of 134a,
enjoy cold dash air.

good luck

FredV · 06-15-2023, 12:04 PM

My 2000 Tropical has a sight glass on top of the receiver/Dryer. I don't know if yours has a sight glass but if it does, after using the vacuum pump, start filling the system with R134a and continue until you can no longer see bubbles in the sight glass with the A/C on max and engine running. Make sure you have enough refrigerant on hand about 3-5 lbs.