Air conditioner problem

[N9Phil]

I am having a problem with the Air Conditioning on one of my 95's. I lost the compressor so I replaced the compressor, accumulator, rear expansion valve (Black Death), Condenser and Flushed the lines. I added an inline filter for the rear and an inline filter with orifice tube for the front line. After running the vacuum down below 500 microns and holding for 15 minutes, I weighed in 4 # of r 134A. The low side pressure was 35# but the hi side pressure was running 350#. Outside temp was 80.

Last weekend the outside temp was 98 and when in town I was unable to get hardly any cooling. I believe that the compressor was shutting down because of high pressure.

Going down the road it would cool some but not where it should be. When I did all the work a few weeks ago I also installed the Kennedy custom fan clutch with the 8 bladed fan. This by the way works great. The temp gauge never went above 195 the whole day last weekend.

On a Air Conditioning forum, the consensus is that I am not getting enough air across the condenser coil. Radiator is fairly new and clean, have Trans cooler and oil coolers in front of condenser coil and they are clean.

Anyone have any suggestions or ideas as to my problem?

N9Phil

[moondoggie]

Good Day!

I'd start with the "A Summer Service Reminder!!" thread in this forum.

Blessings!

[Robyn]

You very well may have a plugged condenser.
How bad did the compressor go away?? If it had run for a long time chewing itself up it could very well have generated a load of crud.
The inline filter you placed up front??? where exactly did that go in the system.
To my knowledge there is no provisions for a filter up front other than the little screen that is part of the orifice tube.
Let us know
RC

[N9Phil]

Moondoggie,
Sorry if I posted in the wrong forum. Where do I find this forum "A Summer Service Reminder"? I usually only go to the 6.5 and 6.2 forums because that is the vehicles that I have and I understand that 6.5 Diesels are a different breed and they have their unique idiosyncrasies.


Robyn, I installed a new condenser and I removed the original orifice tube for the front and installed the filter w/ orifice tube right after the Y.

N9Phil

[N9Phil]

Moondoggie, Sorry that I misunderstood your comment the other day and thanks for bumping "A Summer Service Reminder" up. This however is not my problem. When I replaced the condenser I cleaned everything out (not much there) the radiator is like brand new and the two coolers are spotless. I don't know if I screwed it up when I added the oil. I added 11 ounces when I changed everything (this was the recommended amount for a new compressor, accumulater and condenser) I poured it in the compressor before installing it and it probably pushed into the condenser and stayed there. I guess that I will have to take the condenser back off and see if I can drain it out.
The other day I pumped the Freon out and put enough back in to get head pressure of 275. The rear air works great but not the front. While I have it apart, I will change the front inline filter and check the orifice tube. This system will work right one of these days as long as my patience holds out.

[Robyn]

The pancake compressors dont hold the oil. The oil mixs with the refrigerant and circulates though the system while in operation.
The oil will not stay in any one location.
If your rear system is working well then the problem is obviously with the refrigerant delivery to the evaporator.
your added filter may be the issue on the front unit.

[Petrella]

I have a 1994 Suburban and I am having the EXACT same problem as N9Phil. Today i had NO cold A/C coming out of the vents in the front, but lots of cold A/C in the rear. Pop the hood, Line to the front evap is warm, line to the rear evap is ice cold. last year i changed the orfice tube, the filters, the accumulator and the Compressor because of this problem, after changing all that, A/C was ok and works ice cold when driving down the road but cool when i stop. This year it has been working like total garbage!!. I got cold ac in the rear and nothing in the front. I spray the condensor with cold water from the hose and still dont get cold A/C in the front. This problem is starting to drive me crazy!! but i cant figure out whats wrong here. i got all these new parts and money into this A/C system and it works like total junk!, if anyone knows help me and Phil out will ya! LOL!!!
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Anthony

1994 K2500 4x4 Suburban
6.5 Turbo Diesel
Pyro,Tranny,Oil,Diff temp Gauges, Boost Gauge
FSD Cooler from my GM dealer
Sweet sounding JK Exhaust
Heath Chip
Boost Controller
Crystal Projection headlights, Turn signals and reflectors.
Euro Tail Lights
Cowl Induction Hood
2" Lift
305/70R/16 BF Goodrich All Terrains
11.5" FF 3.73 Posi with Rear Disc brakes
American Eagle 16x10 chrome wheels, style 145
Alpine Stereo,DVD,Navigation System, and Alarm
Indigo Blue Metallic
Pics of my truck - http://www.picturetrail.com/gallery/...21&uid=2685617

[DA BIG ONE]

Changing out the orfice? Go to the variable type orfice "VOV".

A newer condensor design stacked plates far outperforms tube style. http://www.vintageair.com/

When purchasing new parts like filter dryer from GM you'll see update information requiring more r134a in burb over what it came with stock. I used the extra r134a and I can't drive with with any setting over low, even mix some heat for more comfort. Remember, I'm in the sub-tropics, burb is flat black and it's surface gets real hot when parked.

[Petrella]

OK my Sub calls for 4lbs, 0ozs. your saying i need to add more r134a? if so how much??? i installed a new orfice tube from gm last year.

[N9Phil]

Petrella, What kind of pressures do you have and what is the ambient temp? When I had just the rear air working great it was after I only put enough Freon in the system to get a head pressure of 200#. Therefore my system was under charged at the time. With a low charge like this it will feed the rear evaporator first because the rear uses an expansion valve and there will be less resistance than thru the front orifice tube. If I weigh in 4 # of Freon, my head pressure shoots up to 350#. I probably won't get a chance to pull the condenser until some time next week. If I still can't get the head pressure down after cleaning the condenser, I have another back up plan that I will try.

As a rule of thumb, head pressure should be two to two and a half times the ambient temp. On an 80 degree day we are talking around 200#


N9Phil

[Petrella]

Ok it was 85 degrees, and i was getting 40 on the low side and 350 on the high side.

[N9Phil]

Have you tried running water over the condenser with a hose while watching the head pressure?

N9Phil

[Petrella]

i havent tried that, but I definatly will! that will give me a good idea if its a condensor problem

[N9Phil]

I think that I might have solved my problem today. I decided to pull the new condenser and check to see if it might be loaded up with oil. What a surprise. Inside the lower outlet tube was an orifice tube. When I ordered the condenser I specified for a 95 diesel with rear air. If you have a front air only you won't have the Y (this is where the orifice tube is located on my 95's) and the orifice tube must be in the condenser outlet tube. I pulled the new found orifice tube and reinstalled everything, ran a vacuum and weighed in the 4# charge. Head pressure was 225# instead of the 350 I had before. The inside temp got down to 59 degrees. After idling for about 45 minutes head got up to 325 and low pressure was 50. Inside temp went up to 65 degrees. Outside temp was 85 and 60% humidity. Everything looks great.

N9Phil