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Air Conditioner Failure

Missy Good Wench said:
If you have a gauge harness you can charge until the pressure fall into line with specs and the system will cool sweet.

If your system abruptly went warm and stopped cooling, you likely have a failed hose, Oring or other sealing device.

Failed evaporator or condenser.

A good electronic sniffer is the only way to find the leak.

The hoses are known to fail at the crimp area where they meet the aluminum tubing.

Other areas of failure can be the low pressure switch itself (leak through) and or the High side cutout switch on the back side of the compressor.

Put enough 134 in to get some pressure up and run the sniffer all around.

Even the charging ports can leak (check valves will fail)

Evacuate with a HVAC vacuum pump to 29-30 "HG for 30 minutes to remove all traces of moisture and then charge through the low side port.

Never open the high side valve while running, lest thee be found wearing parts of the 134 can on thy person :eek:

If the can gets cold in the upright position, resit the temptation to invert but instead, simply warm the can in a pan of warm tap water. This will make life better.

Doing the charge without gauges is not impossible but one needs to observe the air temp at the vents and how the clutch is cycling.

I use a dual gauge charging harness and a large pail of 134 (looks like a barbeque propane bottle)

The old days of R12 were sweet. Less issues with the stuff.

There is a Product that will replace 12 and 134 called envirosafe. Great stuff and it take a lot less of it to get things working right.

Has a PINE scent so you can tell if the evap has a leak inside the rig.

To do a 12 system you need to replace the charge ports with the 134 style(screw on retro kit)

The envirosafe will work with any of the different oils too and does not scew up the seals in the 12 systems like 134 will.


Check yopu system to see where the juice went.

A major leak may also show signs of oil around the area too.

Best

MGW
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Couple things I disagree on but good write up. GM systems gauge pressures hmmm how do I say it. Too Vague or unreliable for an optimal. Best way is measured chrge. Even a slight over charge can make the system less efficient. I have not use envirosafe, but I have tried many of the other "R12" replacements and it cost alot of compressors.Some of them even have propane in them :eek:
I do A/C professionally on heavy equip and Big trucks and IMHO not worth screwing around. If you run into an r12 system that needs to be opened up, convert it. I have yet to convert one that didn't work as good as before. Besides if you really want to use R12 use it. It's not that expensive anymore anyway. Price dropped alot since nobody uses it. Course ya need a liscense to buy it but they are not that hard get. Least wasn't when I got mine way back when.
 
Dan Hunter said:
Don't they?

Thanks, Ratman. I jumped the connector and the compressor clutch engaged.

I drove it by the the auto hobby shop and the stuck a bottle of 134 in it. Good to go.

Now on to the noisy front brakes.
Click to expand...

Excellent news Dan, -that there usually does the trick. 134 is some hard stuff to seal (not like the 12), and is not uncommon at all to have to do it every couple years or so. Like some have said, overfilling can be a big no-no, so hopefully the guys that did it used a gauge.

Brakes, -yep, -mine are in desperate need of a cleaning/scuff-up/anti-vibe treatment. I think my guide pins and bushings might be getting sloppy too.

Hey, I shouldn't complain, -she is paid for after all....

Glad to hear you got the AC back up and running :thumbsup:
 
Where is the connector that you jump located? My ac doesnt work either, it is missing one of the caps to the valve too. Just want to make sure its not the compressor. I have all the tools to recharge it.
 
DieselSlug said:
Where is the connector that you jump located? My ac doesnt work either, it is missing one of the caps to the valve too. Just want to make sure its not the compressor. I have all the tools to recharge it.
Click to expand...

Michael, go back in the thread, -I posted up a pic of where the plug is on the evap canister.

I got your message, sorry I didn't call ya back yet! -I have been busier than a one-legged cat trying to bury its turd on a frozen pond.

Soooo, how is it going in starter-land??

PM me...:thumbsup:
 
Ratman said:
Like some have said, overfilling can be a big no-no, so hopefully the guys that did it used a gauge.
Click to expand...

Yeah, it was running about 40/200 when we finished. I think I'm going to get my own gauges, test out, and start servicing the truck AND the house.
 
Ratman said:
-I have been busier than a one-legged cat trying to bury its turd on a frozen pond.
Click to expand...

ROFL !!! That there is a brand-new entry in my 'favorite sayings' catalog!

Well done, Ratman!
 
JiFaire said:
ROFL !!! That there is a brand-new entry in my 'favorite sayings' catalog!

Well done, Ratman!
Click to expand...

Thanks guys, -but I can't take full credit for this one, -I stole it from Grandaddy years ago!

He has since passed, but my memories of him will last my entire lifetime. We used to be rollin' in the 78 bronco with the 351W (duals of course), -and if he'd see a VW bus, -or anything hippy-ish in the left lane not going 10 miles over the posted speed limit, he'd speed up next to 'em and tell them they were "number one" (with the appropriate finger of course!) LOL

Then he'd mumble under his breath "goddamn hippy-bastards" LOL

My Grandad is who raised me, --so there ya go, -that prolly explains a lot of my redneck/conservative tendencies, -but I wouldn't trade places with anyone! Yep, I'm redneck proud!!!

You guys (and MGW) are great, -and I am at home here! :thumbsup:
 
Louis, as far as I know oil is only added when a compressor is changed and the system is evacuated

Leo
 
Yes it is a specific amount of oil, When uncertain the comp. is drained and the proper amount is added. Each system is different.
 
Ok, i see the pic now, i must have jumped over it:confused:. I will test it tonight. Ratman, i will pm you on my lunch break today....
 
Dan Hunter said:
It's in the can of freon...kinda like premix.
Click to expand...

Not always. You can still get straight cans of 134. Even the 'other' types of 134 (high mileage, arctic chill etc) have oil but it's usually only enough oil for 'topping off'. If you're doing a complete replacement of all components in the system you'll need to add some straight ester oil in addition to what comes in some cans.....and the amount in a can of 134 varies, some have no oil, some have 1 oz, 1.5 or 2oz's. And I haven't been able to find any 134 w/ oil that DOES NOT contain the dreaded 'sealer' or now 'system safe sealer'.

My brand new NAPA compressor had a bright tag on it that said WARNING: Warranty void if any type of system sealer detected in compressor. :nono:
 
When i reworked my A/C in the '93 6.5 dually last year i installed a new compressor, dryer, hoses and Oriface tube. To get the compressor ready, i used the plain jane can of liquid compressor oil - i think it was 4oz - the FSM should have that spec for each auto as it varies depending upon the system. Poured it into the suction side of the compressor and rotated by hand like the FSM says. Most reman compressors already have the oil in them, new ones likely do not. Then i evac'd it to -30psi, let it sit for an hour to make sure no leaks and charged it. It was a R12 to 134a conversion i was doing, so like always i put a little bit more than the spec said. It's nice a COLD after that, and i'd bet it will stay that way for a long while. With the truck being an R12 system, the 134a is a little different in operation so you should take that into account on a conversion.
Don
 
That's the same way I do mine Don. For some reason, every r-12 conversion I've done cools way better than any of my factory 134 systems. My ole blue in my sig, last week 98 degrees outside, humidity about 80, clutch cycling off at 37 degrees( in the duct) and back on at 40, fan on high, nipples throbbing. :D

If I drive any distance, say more than 40 minutes of driving, the back window has condensate on the outside where the vents are blowing. :thumbsup:
 
Odlaw said:
. For some reason, every r-12 conversion I've done cools way better than any of my factory 134 systems. :
Click to expand...

The reason is very simple. There is almost no difference execpt that new vehichles that came equipped with R134 also have more "effiecient" compressors. Basically they put smaller compressors on to save gas hp etc. Most nowadays come with those little sandens which are mostly 6 cfm. You go old school on an early 6.2 with the Gi-goondo Harrison and that sucker pumps 10 cfm. When you kick on the a/c proably lose 20 hp but damn does it cool. I have argued to many that converting an r12 system will not make is cool less. The only thing I have seen with conversions is on low rpm diesels some get very slight less cooling at idle.
My old R Model had a/c in the cab but nothing else(new cab) so I did that system from scratch. I used an over sized condensor and a 10 cfm York compressor. On a 95+ degree day that thing would frost the windows. I had optimum 39 degrees out the duct. That is as cold as you can go without freeze up.
 
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