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Topic: R134A amount in 2003 U320 40' (Read 585 times) previous topic - next topic

R134A amount in 2003 U320 40'

What is the total weight of 134A in the dash ac system for a 40' U320 2003?

A friend of mine is coming over tomorrow and will vacuum out the system and refill.

I read one post that indicated 5 to 5.2 lb.

Thank you
2003 U320 4010 - SOLD
2014 RAM 1500 Ecodiesel

Re: R134A amount in 2003 U320 40'

Reply #1 –
Can you give FOT a call? It might be on a label somewhere on the system components.
Richard & Betty Bark & Keiko our Golden Doodle
2003 U320T 3820 PBDS
Build # 6215
MC # 16926
2016 Chevrolet Colorado 4X4 diesel

Re: R134A amount in 2003 U320 40'

Reply #2 –
Fill by PSI/gauge readings.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: R134A amount in 2003 U320 40'

Reply #3 –
Do what Brett says.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: R134A amount in 2003 U320 40'

Reply #4 –
I couldn't get the pressures to match what r-134 should be on both the high and low side. Put a thermometer in the register in the dash and charged until temp dropped to 40 deg. and ignored pressures. I know something isn't right but cannot find a restriction so went with if it works leave it alone.
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: R134A amount in 2003 U320 40'

Reply #5 –
We have a gauge set, but find the best way is to add refrigerant until dash feels cold and/or have thermometer in dash outlet.

Have a permanent dash thermometer with a wired sensor probe that is placed inside dash plenum, a few inches from evaporator coil.

We see temps about 38 degrees at the evap coil.

Re: R134A amount in 2003 U320 40'

Reply #6 –
38 deg is incredible. Outside air temperatures, inside temperature affect everything. If you are seeing 40 deg drop from inlet to evaporators to outlet you are doing real good. 134 can be easily overcharged and perform poorly. I charge by temperature drop and seek to stop at the peak. Many factors affect performance.
Scott

Re: R134A amount in 2003 U320 40'

Reply #7 –
Quote from: dsd –
38 deg is incredible. Outside air temperatures, inside temperature affect everything. If you are seeing 40 deg drop from inlet to evaporators to outlet you are doing real good. 134 can be easily overcharged and perform poorly. I charge by temperature drop and seek to stop at the peak. Many factors affect performance.
Scott
The air inside is the factor as it is on recirc usually. Works like a big refrigerator keeps getting the output returned. If you put the dial on fresh air you would be trying to cool the outside air and never get to the 40 deg. I get.
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: R134A amount in 2003 U320 40'

Reply #8 –
You can also look at the sight glass on the dyer. Most have black tape over the sight glass that you will have to remove. Add till no bubbles are seen, wait a week and re check if you are losing 134a 


John Patrick
2002 U270

Re: R134A amount in 2003 U320 40'

Reply #9 –
Our experience is sight glass is not useful for R134A and not included in new filter-dryer.

Re: R134A amount in 2003 U320 40'

Reply #10 –
Should be able to call FT and get the exact charge weight. 134A doesn't like to be over charged head pressures will go sky high, to low the system will go into a vacuum. Also if you replace components like the dryer you will need to add PAG OIL.
Bruce, Linda, and Macy
Zoey RIP 1/20/19
1999 U295 40' build #5400
2017 silver Jeep Wrangler, 1260 watts of solar on top
Moving around the country
 

Re: R134A amount in 2003 U320 40'

Reply #11 –
5 pounds was std
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4