Grease Monkey

HA! Figurd it out! Ron

SH!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!t!!!!!!!!!!!!!!!!!!!!!!!!!!!

Got me wondering! Ron

Dale, assuming from your post, your dash A/C is not plumbed in at this time. If this is so, why not consider teeing the dash unit into the refrigerant system. Also, be sure the condenser is not lying flat. The outlet line on the condenser (line going to drier/expansion device/evaporator) must be lower than the discharge line coming coming from the compressor. This is so liquid refrigerant floods the evaporator core. I realize that your condenser will be rather small for the combination of evaporators, but it would certainly be worth a try. Generally speaking, I feel your compressor should not have a problem suppling enough refrigerant.

I live in south Texas and regularly drive my B model Mack in 95-105 deg. temperatures and bright sun. I rigged my system up as explained above. I purchased my components from Danhards near Dallas. We probably have similar units under the dash, however I have 36" sleeper on my truck. Under the bed I mounted a medium sized box unit (A/C-heater) and ducted into the sleeper compartment. My condenser is about the same size as yours, with two electric fans mounted to it. For lack of space, I mounted my condenser vertically between the left frame rail and driveshaft under the sleeper. Locating the condenser in this position is not a good practice because it gets little or no ram air at highway speeds, but it does work acceptably well. Some riders have commentented "you could hang meat back here!"

Grease Monkey

This is my 3rd AC installation in my B67. This is going to be right- or else! Cab is very tight, heavilly insulated with marine lead foam, all firewall openings sealed or grometted and dark tinted glass. SO, air conditioning should be a piece of cake. Let me relate my experience. During the initial build I installed one of those slick little combination heat/cool units from Old Air Products. These are designed for limited space, as in street rods, and I installed it behind dash, drivers side, replacing the original heater. It fit fine and it worked- sorta. It would blow 50 degree air, but it just didn't have the capacity to deal with a 95 degree day here in the south. These units are "compromise affairs" too small to really cool or really heat. So, I disconnected it, leaving it in place to function on heat only. Next I bought a big underdash unit, cool only. from Vintage Air Products. There is no space under the dash on a B67 of course, but there is space on the floor betwen the two air seat bases, and thats where I mounted it. This was a big improvement, and it could handle 90 degree days just fine. But, it gets hotter than than here, and it was running full blast to keep you marginally cool. Not good enough either. About now I discover that there is a difference in condensors- round tube type for R12 and flat squart tube types for R134. I had the round type. And moreover, mine could not be mounted forward of the radiator- I had to mount it between the frame rails, horizontally just ahead of the 5th wheel- two mushroom fans forcing air through it. This week I swapped it out and installed the flat square tube type. Also broke all the hose fittings apart, cleaned them and installed new O rings- the green ones by the way- not black ones that are only good for freon. Then I buy the biggest cool only under dash evaporator- this from Wheels of Time in Philadelphia. I saw this unit in a buddy's car and it will blow your hat off- really moves alot of air and it has alot of cooling coils. It will go on the floor between the seats. Hopefully I'll get it today and install it this weekend. Will report my further experience. Maybe you chaps can benefit by knowing what does not work.