Recharging OTR Air Easy or Not ??

[scanzel]

Four years ago I had my over the road air redone, they replaced the 05G compressor and some other items and recharged the system 134 Freon. This past August while coming back from Ohio hit the ac switch and the check system light came on probably meaning no ac, so it was very uncomfortable coming home. Haven't had the system rechecked yet but how hard would it be to buy the gauges and 134 Freon and check and recharge it every year myself. I have a Carrier Transcold service center close by but that will cost $$$ to have it checked every spring and recharge. 

[Gary Hatt - Publisher BCM]

I checked with MCI a couple of years ago and they wanted about $1200 to recharge the system and go through it to ensure there were no leeks but guaranteed it would work.  So I paid a friend of mine to charge it for about $100 and it worked for about a year before needing to be recharged again. 

[richard5933]

Cost me about $1k to have ours checked and charged on the 4106 as well. They ran dye through the system first looking for leaks but found none. From what I've read, it's pretty common for these systems to need recharging. Don't know all the details, but the place that normally works on our bus couldn't do it themselves and had to send it out because of the volume of refrigerant needed. You might want to check out if the DIY equipment can handle the volume in your system before investing in it.

[gumpy]

These are sealed systems. If they are low on freon then you have a somewhere. Recharging will only put more freon in that will leak out.

You need to pressurize the system, preferable with dry nitrogen to locate leaks, or use dye as indicated above. Then, you need to vacuum the system down to recharge it.
You should also replace the moisture filter. The MCI takes 24 lbs of freon.

[Geoff]

The buses built in the eighties used R-22 freon.  You can buy a 30 lb cannister of R-22, but you are supposed to be licensed to buy it and install it.  An alternative is to go with a retro fit to upgrade it to R134a.  No license required, and you can buy R134a system leak sealer.  I've done it with R12 in cars but you'll have to see if the R22 systems will take R134a.  For DIY, you will have to get a set of gauges and find out what the pressures are, high and low.

[ol713]

  Hi;
    Good rule of thumb,  "if it works fine, If it is broke, don't fix it".
    Too many leaks and too many old parts to make it worth while.
                                                      Merle.

[sledhead]

I went to harbor freight for the gauges and got a 10 lb bottle of 134a  from my auto parts supplier to top up the featherlite .It only needed 1.1 lbs and it is really cold now

had a a/c buddy show me how it is done and you tubed it as well


so now I can recharge it my self  





https://www.harborfreight.com/ac-r134a-manifold-gauge-set-62707.html


Dave

[chessie4905]

Anybody that intends to keep the onboard factory ac system needs to learn how to service system themselves, take the certification test to buy the refrigerant, get a set of gauges, and buy a propane tank size of refrigerant. These systems will drain your wallet if you have to take it to a service center. Especially the older systems before govt. regs dictated improved sealing systems. Probably after middle 90's. The old systems commonly leaked, especially if vehicle sits frequently for days or weeks. Go to a transit company and ask about their experiences.

[luvrbus]

It takes a real good vacuum to pull a MCI system down the H/F vacuum pump won't do it so don't waste money on 1  

[bigred]

These are sealed systems. If they are low on freon then you have a somewhere. Recharging will only put more freon in that will leak out.

You need to pressurize the system, preferable with dry nitrogen to locate leaks, or use dye as indicated above. Then, you need to vacuum the system down to recharge it.
You should also replace the moisture filter. The MCI takes 24 lbs of freon.

What he said!!!!!!