AC pusher fan for condensor
- Thread starter tbrumm
- Start date
tbrumm
Full Access Member
I appreciate all the suggestions guys. I finally got some good gauges and had some time to do some checking this weekend. Just a few more notes about my system in particular. The shop that worked on my truck did not replace the filter/drier which is mounted up front by the condensor. The filter/drier does have a sight glass, which I cleaned, but really can't see anything in there. The refrigerant is 134a. I do have the heater cut off installed and that shuts off the water flow to the core when the system is set at MaxAC. The door in the plenum that shuts off the outside air flow in order to recirc inside air does appear to be closing as you can hear it "thunk" closed when setting the knob to MaxAC. Vacuum lines seem to be in good condition and I don't hear any leaks or see any deteriorated vac hose. I also checked the drain hole in the evap housing and may have found part of my problem. I noticed it was dripping but wasn't drippping much. I stuck a wire up in there and took a shower! A lot of water drained out of there - that could not have been helping the cooling! Isn't it amazing how simple stuff like that can get ya. I then hooked up the gauges. It is about 80° here today. With the truck cold and shut off: low=82/High 82. I then started the truck and at high idle and the system still cold the low=8/high/120. After 10 minutes run time and revving the engine to 1800 the low dropped into vacuum at -2 and high dropped to 105. Going back to idle , the low went back to 18 and high to 150. Vent temp went as low as 60°. This is just with the truck sitting in my driveway with no electric fan blowing over the condensor. Revving the truck again after about 5 minuted to about 1800, the low was 4 and high 160. Returning to idle, the low was 18 and high 155. The high side line at the compressor is very hot with the low side line only slightly cool. The expansion valve at the evaporator is pretty darn cold and sweating. I hape I have provided enough info - I appreciate any help you guys can offer, Thanks - Todd
tbrumm
Full Access Member
The expansion valve was installed by the shop and was supposedly new. These days though, new does not always equal good. Thanks for the help. I guess I will get the truck back in and have the system evac'd and have the valve and drier replaced.
FordGuy100
Registered User
Sounds like an obstruction or really low on refrigerant.
FoMoCo
Full Access Member
I had the same problem, so I installed 2 pusher fans that are tied to a relay. They help, got one from Summit, the other I don't remember. The problem is the fan clutch does not kick in and the head pressures get to high. These engines run cold. I would install at least one and check your fan clutch (high dollar) 170 at parts stores, you don't want to know how much from the dealer
Pressures overall look low, and I would look that expansion valve over for numbers and try to find out if it truely is an r134a valve or if they just threy a replacement r12 valve on, that will make a huge difference in refrigerant throttling performance, also make sure the expansion valve is wrapped with insulating material and if it has a thermal probe coming off it that is supposed to lay against the pipe coming out of the evaporator, make sure that is all insulation wrapped together with the black sticky stuff, ( I can dig up a link if there is none)
79jasper
Chickenhawk
Might be good just to have in this thread.
And as far as pusher fan, you dont need a fancy one or even a huge one. A 10 or 12" cheap pusher will work fine for ac assist, mount it to a corner of the condensor and it will get a good amount of head pressure drop at low speed. Dont mount it to where any of it blocks the sensor on your fan clutch when not on or you could mistakenly cause yourself an overheat problem
Factory Air part #59010 You can get it at Advance same part no should show up at napa etc, they all get the same stuff . Theres a few other types that will all work well too, they are all black and sticky
79jasper
Chickenhawk
That'll work on the lines across the firewall also correct?
generally so
tbrumm
Full Access Member
Here is the thermostatic switch I got. Matches the old Ranco switch that was in my truck and the truck harness plugged rght in. I put it in the freezer for a bit and then tested it on the truck and it did shut off the compressor like it is supposed to. I assume the bend is supposed to be in the capillary tube as that is the way it came in the box. I left the bend in it when I inserted it down into the evaporator. I also insulated around the expansion valve. I have not tested it out, but I'll do that today and see how the system acts and let ya know. Hope everybody had a great 4th! Todd
