98 LX AC not working

[nitsuj]

Howdy gang. Like the title says, I got no AC, and it's starting to get warm enough to need it! So, the compressor isn't kicking on. Before I dig into the normal trouble shooting, I figured I'd ask here to make sure there isn't a common problem to look for.

Thanks

 

[Scottb4857]

Refrigerant too low so compressor won't kick in is common at age. Several threads on the subject just do a search. You can pick up some refrigerant with uv dye in it and a uv kit at Wal-Mart for $30-$35 to check for leaks. Suggest a semi dark garage so uv really stands out when you check all the lives for leaks.

 

[nitsuj]

Thanks for the reply. I didn't realize that low refrigerant would prevent the compressor from kicking on.

 

[Scottb4857]

First, open the dust cap on the front a.c. port to see if pressure still in system. If none at all then probably a decent leak in system, if still good pressure then may just be low.
I rolled the dice on mine and bought a self charge kit with some sealant and dye in it. In order to change the system you have to get the engine up to temp and have the a.c. running while putting the refrigerant in. On mine about 5 seconds after starting to charge heard the compressor kick in. The one small can actually wasn't enough so topped it off the next day. Checked for leaks for the next several days and never found one. Two months later a.c. still nice and cold, got lucky so far. If you do charge yourself make sure you pay attention to the instructions, especially the part to rotate the can 90 degrees back and forth while charging otherwise dyes, oil, and Freon won't flow in correctly

 

[crimsonaudio]

Mine did this last year - I obviously had a small leak. Instead of buying the refrigerant with the dye for visual inspection for the leak, I bought a recharge kit (the gauge can be reused in the future) that contained a sealant in it as well. Now the AC works like new and I've had zero issues.

This is what I used: http://www.autozone.com/a-c-chargin...ith-electrical-driven-compressors/974769_0_0/

 

[nitsuj]

Thanks guys, I'll grab a can of the stuff with the sealant in it and check it out.

When you say to check the pressure, do you mean with a guage, or am I just listening for pressure?

 

[crimsonaudio]

Thanks guys, I'll grab a can of the stuff with the sealant in it and check it out.

When you say to check the pressure, do you mean with a guage, or am I just listening for pressure?

You can buy the refill cans typically with a (reusable) gauge.

I've heard reports of the gauge being off on some of these, and it's potentially dangerous to overcharge the AC system (the compressor can be destroyed), so be careful not to overfill. I used the gauge but also checked the AC output in the trucks periodically and quit as soon as it got nice and cold.

 

[Scottb4857]

You can buy the refill cans typically with a (reusable) gauge.

Most of them, and specifically the better ones, use a rotating the dial that you match to ambient air temp. This is a crucial step to avoid under or overfilling. Put what is needed to have correct functioning and don't try to force in more. Like crimson said more is not better.

 

[crimsonaudio]

Most of them, and specifically the better ones, use a rotating the dial that you match to ambient air temp. This is a crucial step to avoid under or overfilling. Put what is needed to have correct functioning and don't try to force in more. Like crimson said more is not better.

Yah, the one I linked above has that. But I'd still be careful...

 

[duggy]

Do it the right way by renting a proper vacuum and gauge kit available at any autoparts store. Air conditioning can be very finicky and using those cheapo cans is not a surefire way to know if your AC system has proper pressure on both the high and low side.

 

[Scottb4857]

Hey Duggy, just for discussion sake: Would there be any benefit to renting a vacuum and gauge kit, completely evacuating the system, then refilling with fresh to factory specs? On most systems I have been told that as long as it is working properly then the freon/oil doesn't degrade and therefore no point in doing a fluid change for lack of a better term.

On mine the po had told me they tried re-charging but stopped working after a week. I assumed this meant a big leak or worse. I threw a can in hoping to find the leak/diagnose the problem(s), but two months later still working like a champ both front and rear systems. I may just be naive, but makes me think they just didn't charge it enough or correctly.

Your thoughts?

 

[PADDO]

If you go down the self charging route I'd recommend printing a copy of the site gauge table that shows what you should see in the gauge under what condition. Observe the site gauge in conjunction with a temp compensated filling gauge and a slow, more is not better approach, is what you want to do. Don't invert the can and get liquid in the LP side, when it goes through the compressor it has an embolism and you get to see if the compressor relief valve works!!!

 

[duggy]

Hey Duggy, just for discussion sake: Would there be any benefit to renting a vacuum and gauge kit, completely evacuating the system, then refilling with fresh to factory specs? On most systems I have been told that as long as it is working properly then the freon/oil doesn't degrade and therefore no point in doing a fluid change for lack of a better term.

On mine the po had told me they tried re-charging but stopped working after a week. I assumed this meant a big leak or worse. I threw a can in hoping to find the leak/diagnose the problem(s), but two months later still working like a champ both front and rear systems. I may just be naive, but makes me think they just didn't charge it enough or correctly.

Your thoughts?

Freon does not degrade, but your scenario and the O.P's scenario is totally different in comparison. I never like to use the cans that have the built-in gauges as they contain the leak sealant which can wreck havoc on your AC system if it gets lodged into an expansion valve. I suspect that the leak sealant/freon combo you bought from the auto-parts store sealed up your system well enough to "resolve" the problem but it's not a permanent fix in my eyes, especially if you want to go on a trip with your family and your AC decides to cut out all of a sudden, hundreds of miles away from home.

A vacuum gauge will serve to check the system for leaks. You vacuum the system, leave it for 30 minutes, and see if you lost vacuum. You can also blow compressed air into a system and spray around the lines with soapy water after you have found that you are losing vacuum.