nunan Posted July 7, 2011 Share Posted July 7, 2011 i'm having a problem with my 06 e450s, they're twins. With the proper amount of freon in both of them (5 3/4) as marked by the manufacturer, my pressures are all screwy. my high side on both of them is fluctuating tremendously, from 110-240, and my low side is steady at 50. it cools, but not well. i looked it up on the workshop manual, and i'm not really getting a definitive answer. from what it says, it could be overcharged (i recovered and pulled a vacuum for 30 minutes and let it sit for 15 just to be sure it was empty), the engine could be overheating (sitting at 190ish idling in shop), or inadequate condensor airflow (i have a carpet fan pointing directly at the condenser) the belt on both buses squeaks while idling. backround on the bus, its an e450 chasis cab with the school bus conversion, 6.0l diesel single alternator, with rear a/c but only one compressor and one condensor, uses the stock evap and also one up on the bulkhead as well. any help or direction would be great, thanks! Quote Link to comment Share on other sites More sharing options...
joshbuys Posted July 7, 2011 Share Posted July 7, 2011 check the orfice tube for metal debris, your compressor may be coming apart. Quote Link to comment Share on other sites More sharing options...
nunan Posted July 7, 2011 Author Share Posted July 7, 2011 thats what i was leaning towards, but figured id ask while i was around. Thanks Quote Link to comment Share on other sites More sharing options...
Brad Clayton Posted July 7, 2011 Share Posted July 7, 2011 These units are equipped with a scroll style compressor and the pressures will fluctuate under normal operation. However, if you are seeing the pressures you mentioned and it cools with higher rpm and doesn't cool at idle, then the compressor is shot. You can't beat a piston compressor for cooling capacity at low rpm's! Quote Link to comment Share on other sites More sharing options...
nunan Posted July 8, 2011 Author Share Posted July 8, 2011 even with the high side fluctuating at such a rapid pace it would be considered normal? i will check it at idle vs high rpm cooling. thanks! Quote Link to comment Share on other sites More sharing options...
cbriggs Posted July 9, 2011 Share Posted July 9, 2011 Also check for desbris in the cooling stack, that could be restricting airflow thru condensor. If possible watch guages while driving to see if they become more normal, indicating airflow concern. Based on your pressures it seems overcharged or overheated. Quote Link to comment Share on other sites More sharing options...
Jim Warman Posted July 13, 2011 Share Posted July 13, 2011 Almost 6 pounds of R134a? That must be quite the system..... I'd maybe check the manufacturers website and see for sure... I was looking at a motorhome today and the motorhome manufacturers tire placard said 45kPa.... 6.5 PSI of air sounds a tad soft so I imagine that there may be a misprint on the placard... 450kPa might be more like it. Just a thought... isn't it odd that they'd both be doing the same thing? Quote Link to comment Share on other sites More sharing options...
ktmlew Posted July 13, 2011 Share Posted July 13, 2011 I had similar issues when someone loaded the a/c machines tank with air by opening the high side valve when the vehicle was running...figured-out the machine wasn't prpoerly purging the tank of non-condensable gas. Quote Link to comment Share on other sites More sharing options...
GregH Posted July 15, 2011 Share Posted July 15, 2011 The five transit buses that the city owns use about five and a half pounds of freon for the rear system. They don't seem to be really sensitive to freon level.. I agree with a compressor going out... Quote Link to comment Share on other sites More sharing options...
Mbl35 Posted July 22, 2011 Share Posted July 22, 2011 So, how did you make out? Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.