ok guys, i hope you can help me out on this one. i noticed today that my air conditioner was getting warmer (again...on going problem) and that my truck was hissing whenever i shut if off. i think i diagnosed the hiss down to the orifice tube connection. when i looked at it there was a white plastic "keeper" that looked like it fell out of the spring retainer and when i try to put it back in it keeps kinda falling out. doesnt want to stay in. my questions are 1) what does that thing do?...2)would that make that connection leak?....and does anybody have the part number for that part? its a white circle with 4 little "clips/retainers on it about the size of a nickle-ish. thanks for all the help in advance


p.s what a way to spend my fathers day ha ha

 

ok i think i found the part i was looking for i went to fordparts.com and looked a 1994 f150 6 cyl and under the hvac i am looking at part 198101 but it has a star beside so not sure what that means

 

the white plastic cover thing is just a cap to kep the dirt out, and is not rally doing anything. best thing you can do is put a can of die in the system to see where your leak is, then post again, and we will tell you how to fix it

 

ok i got a quick question the compressor clutch shouldnt be turning if all the freon leaks out right? when i turn off the key im hearing a hissing sound up around the accumalator but i havent found it yet. but when the truck is running and i turn on the a/c the compressor is spinning. the hose coming out of the accumalator running up on the firewall is no longer getting cool to the touch. where would be a common leak point in that region?

 

anybody live in the tucson area with a set of gauges and a vacuum pump that could give me a hand. i would really like some help figuring this thing out and i dont want to take it a shop. id like to learn myself. i cant pay much (very limited budget) thats why im messing with this thing, but i do have some cold beer (dont have a garage either) so we'll be working in my driveway but im willing to shut up and listen (lol) im just tired of shooting in the dark and this truck is almost on its way to that big junkyard in the sky ha ha not really but i am frustrated

 

The hissing may be vacuum leaking from the "coffee can" reservoir. If your system is low or out of refrigerant the compressor should "short cycle" or not come on at all. Your low pressure switch, mounted on the top side of the accumulator, may be defective allowing the compressor to run. It is not good for the compressor to run when low on refrigerant as the oil will not circulate through the system thus damaging your compressor. You really need a set of a/c manifold guages to read static and running pressures to determine your refrigerant charge. If you do not own a set of guages they can be obtained at Autozone on their loaner program.

With the reduction in efficiency of your system it sounds like you have a leak as refrigerant does not just "normally" leak over a period of time.

 

what does the coffee can actually do? i replaced that low pressure cutout switch when i replaced the acumalator 2 weeks ago so i dont think that is bad. i can get a gauge set from autozone but im not sure at the pressures im looking for. i dont want to blow out any seals or anything so what pressures would i be looking for from the high side and low side? also how much vacuum should it hold and for how long?

 

OK here's an update: i put a generic pressure gauge (the one that came with a can of freon) and it was reading over 70 psi without the truck running. with the truck running and the a/c turned to max when the a/c clutch cycles it will drop down to about 30-35 psi but when the a/c clutch disengages, the pressure goes right back up. is that correct? when i bleed the system it seems like hot air blows out no freon, but a little oily. i don't know what the heck is going on with this thing?
here's a dumb question.....when i put the new compressor on, is there any way i could've swapped the manifold lines (like got them backwards) or are they idiot proof and only go on one way or is it possible to swap them?
also how can the refrigerant leak out but not depressurize the system? i know just about nothing about a/c but I'm trying.
thanks for all the help in advance again

 

You need to throw that "tire guage" away and get a set of real a/c manifold guages so you will know what your high and low pressures really are. It sounds like you are low on refrigerant and the compressor is "short cycling" as described above.

I still think you may have a leak since the system was cooling once and now is not up to par. If you do not have access to a leak detector you may be able to spray a soapy solution on each connection in your system to see if there are bubbles present. If so, your leak(s) should be repaired before attempting to charge the system and avoid future problems.

The 70lb reading you got with the engine off is called "static pressure" and in a full system this number will be about the same as your ambient temp. If the engine compartment is hot this number will go up accordingly. Your low side pressure should be 30 or lower and your high side should be 2 - 2.2 times the ambient temp. So if the ambient temp is 90 then you should see 180 - 198 or so. Pressures should be measured with the engine at 1500 rpm, high blower fan, on max cool.

When you say you "bleed" the system I am assuming you mean you are pressing the valve stem at the schrader valve that is releasing refrigerant. When the refrigerant (freon) comes out it will be in the form of a gas, not liquid, and it is normal for you to get oil along with it. If you continue to release your refrigerant you will need to replenish it or your system's efficiency will continue to diminish and no, you cannot reverse the manifold lines at the compressor as they will only fit in the right direction.

 

damn i love this website. thanks for all the help ill be working on it again tommorrow

 

I quote myself, you must have missed when I told you to put a can of die in the a/c system to help you find the leak. you just push the can aginst the fitting, and put 3 seconds worth in. it says use a black lght to see it, but if you have a leak, it will show up. my leak was where the compresser cut out switch screws on, I still had a leak with the new switch, so I put an o ring behind it, and no more leak.