Hello. I am looking for Refrigerant (Freon) Type and Capacities for: Dozers: Komatsu pc78 and Volvo EC210 Would anyone be able to help me out? Thank you.
I would assume R-134a, if you got a manifold guage set for 134 it will connect, if it's R-12 it won't. I ran five cans in a Komatsu WA500 loader, but there should be a decal near the compressor or the dryer stating the amount. Heavy equipment is no different than an automobile system.. AC is AC..
Assuming these have thermostatic expansion valves, and not fixed orifice tubes like Ford or GM trucks, I like to charge by the subcool method. Fix a very accurate temp probe to the liquid line as close to the condenser outlet as possible and insulate it so you are reading temperature. When there is solid liquid at that point indicated temperature will agree with the temperature reading on the high side gauge. Add a little more refrigerant until the indicated temperature on the high side gauge is about 10 degrees higher than the actual measured temperature. This ensures that the last few turns of the condenser are full of liquid and being subcooled below their condensing temperature point.
Good point, that WA500 has an expansion valve, but, it was buried behind half the interior, I got a new one but never put it on. It also had 2 separate condensers with their own fan, and there is a resistor under each fan shroud that appears to be susceptible to cracking, both of those were broken. Between the 500 and a Cat 966 I spent over $3,000 in parts to get the AC working, the Cat condenser was almost $1,000 by itself. Cray cray...
Thanks for your help guys. I wasn't able to find the label on one of them. Called dealership for Komatsu and they let me know how much charge it is supposed to take. 1.5lbs. Compressor is supposed to be pumping Gas not Liquid? Am I wrong? Expansion Device turns high pressure liquid into low pressure liquid , Evaporator turns low pressure liquid into low pressure gas , Compressor turns low pressure gas into high pressure gas , Condenser turns high pressure gas into high pressure liquid . ?
Lets say the condenser is running 275 psi for the sake of this discussion. When the high pressure gas comes out of the compressor it is SUPERheated meaning heated above the condensing point. Lets say it was 250 degrees when it came out. The first few turns of the condenser gets it from superheated to saturated temperature/pressure. That it is the pressure it would be if you had a tank of the stuff heated to 153 degrees. The rest of the way down the condenser you have drops of liquid condensing on the walls mixed with vapor that has not condensed yet all at 153 degrees. At the bottom, once it has all condensed, there will be a few turns of the condenser that are full of liquid. Since there is no more vapor left, all this liquid can do is to cool down a little more on its own. This is the SUBcooling. If the liquid exits the condenser at 143 degrees, you have 10 degrees of subcooling if the pressure is 275. Chart is here: http://www.jaguarforums.com/forum/a...-type-ac-not-cold-3990349207_d942659e8c_o.jpg If there is not enough refrigerant in the system then there will be less liquid in the bottom of the condenser and subcooling will be less. Liquid temperature might be 148 degrees. If there is too much refrigerant then the condenser will begin to become packed with liquid and there will be less of it available to condense gas from the top and the pressure will go sky high. Subcooling will be higher.
You're welcome Sir. Also remember you should pressurize the system to around 90 psi and see if you get a pressure drop, then vacuum down the system for at least an hour to evac the water and air in the system, before filling the system check that the vacuum holds as well. Good luck!
Thanks guys. Help much appreciated.