A/C question

[Busnut83]

Is the valve on the coach air compressor 3 positions or 2,,,  Where the 134 guage connects,,, there is a valve that screws all the way in and was already screwed out,,, When i put my guages on it did not read,,, then i screwed it half way down and the guages read,,, Question 1,,, where should the valve be when adding 134 and where should it be when finished,,,   added  about 15lbs compressor now works,,, will check for leaks with soapy water and watch guages... 20 on low side and 200 on high at present time... First time using coach air on Prevost...

[stevet903]

Sounds like it is a rotolock valve - does it look like this - http://www.emersonnetworkpower.com/en-US/Brands/Liebert/Documents/Discontinued%20Product%20Documents/SL-17511.pdf

It's a good system - backseating (screwing all the way out) is the normal position and seals the port so it doesn't leak.  Screwing in a couple turns opens the port and allows you to check the pressures and fill the system with freon.  Completely closing the valve seals the system so it can be disconnected at the valve - allowing you to change the compressor or whatever is connected at the valve without losing all of the freon

[Busnut83]

Thanks,,, just what needed to know..... Are the pressures good? 20low   200 hi

[stevet903]

The pressures will depend on the temperature.  A full charge is 24 lbs according to the manual - http://prevostparts.volvo.com/technicalpublications/pdf/pa1082-22.pdf
Here's a manual with how to check the charge and the temperatures/pressures for an MCI - look on page 40 and 41
www.transportaircon.carrier.com/Files/Bus/Local/US-en/T312.pdf