Author Topic: A/C recharge kit? (Read 3331 times)

cube1980 · « **on:** July 21, 2008, 07:35:12 pm »

Has anyone tried the A/C recharge kit that they sell at CT?

I picked one up today for $50 (comes with the hose, pressure guage etc). I tried it but still have no A/C There was pressure in the system but I'm not getting cold air. Any recomendations on what to try next?

Quantum TD · « **Reply #1 on:** July 21, 2008, 08:10:33 pm »

If you're converting to R-134, then you need to flush the whole system, replace all the seals, and replace the receiver dryer.

If you're topping off with R-12 or equivalent and you lost all your freon, then you proably have bad seals (or a leak somewhere anyways). You really should flush the whole system and replace all the seals either way.

Generally speaking, if you're doing a recharge on a system that hasn't had freon in it for a long time, then you should replace the following:

1) seals (coat with dielectric grease)
2) receiver/dryer
3) expansion valve
- test compressor for engagement, and output.

Then, suck vacuum on the system for about an hour and check for leaks.

If you do all that, the parts should cost about $100-150, and you're guaranteed to have freezing AC that will last more than 1 year.

Now, if there was freon in the system, and there are no bubbles visible in the sight glass, then you proably have either a bad compressor, or a bad expansion valve. Either way, it's a good idea to co thru the checklist above.

tmichaud · « **Reply #2 on:** July 22, 2008, 02:19:43 pm »

I used one this year.

The car was new to me, but has a sticker saying it was already r12a.

Thought I would give it a try before digging in. So far AC has been blowing cold for 1.5 months without issue.

It must have a leak - but I am guessing seals (CT also has the AC stop leak) I used that first, the the refill kit.

If it runs out again, I will have to really dig into it.

zukgod1 · « **Reply #3 on:** July 22, 2008, 02:47:45 pm »

Quote from: "Quantum TD"

If you're converting to R-134, then you need to flush the whole system, replace all the seals, and replace the receiver dryer.

If you're topping off with R-12 or equivalent and you lost all your freon, then you proably have bad seals (or a leak somewhere anyways). You really should flush the whole system and replace all the seals either way.

Generally speaking, if you're doing a recharge on a system that hasn't had freon in it for a long time, then you should replace the following:

1) seals (coat with dielectric grease)
2) receiver/dryer
3) expansion valve
- test compressor for engagement, and output.

Then, suck vacuum on the system for about an hour and check for leaks.

If you do all that, the parts should cost about $100-150, and you're guaranteed to have freezing AC that will last more than 1 year.

Now, if there was freon in the system, and there are no bubbles visible in the sight glass, then you proably have either a bad compressor, or a bad expansion valve. Either way, it's a good idea to co thru the checklist above.

You do not need to flush the system unless you had a mechanical failure. If you have leaks currently then you need to address them. If it's just low you CAN top it off with 134 and it will work just fine.
What Quantum TD has posted is correct if you have a leak and the system has been empty for a while, you just as well replace all the seals, it's not that hard to do and your better off replacing them, Replacing the dryer is also a good idea again if the system has a leak or has been empty for a long time and if your already replacing the seals replacing the expansion valve as mentioned above is a wonderful idea.

It sounds like you have a good leak going on so I would go with Quantum's suggestion and just redo everything you can so it will continue to work for years. Again unless you had a mechanical failure you don't need to actually "Flush" the system.

Quantum TD · « **Reply #4 on:** July 22, 2008, 03:27:25 pm »

I just post the flush idea since, you can buy a flush kit for about $50, or take the individual parts to your local AC shop, and they can flush them for about the same $. I had a local shop flush my mufflered-hoses, and the condensor (a parallel flow one) and they charged me $38. I flushed the other hoses and the evaporator in the car with one of those flush can kits in about 5 minutes. After all new seals, a new R/D and a new Expansion valve, I took it to my local mechanic. He sucked it down and it blows icicles.

The main reason I suggest flush down is to get out any debris on older systems, and it's piece of mind. Most cars I work on are 20+ years old, and the parts I put on them have been hanging around for about 10 years in storage or exposed to the elements. I like to do things once, and never worry about them again. But that's just me.

zukgod1 · « **Reply #5 on:** July 22, 2008, 03:33:42 pm »

No your right, I condone the flush as well but not usually on a system that hasn't had a failure of some kind, the oil that's left in there from the r12 will help the 134 stay in the system longer. If ya flush it all out the system will leak down. It could take a damn long time but it will happen unless you replace all the rubber hoses as well.

Possum79 · « **Reply #6 on:** July 22, 2008, 09:38:26 pm »

Well I highly recommend if you go from r12 to r134a you flush the system. The oils inside do not mix and with them being able to turn acidic, just dont do it. If your already on a 134a system you can covert to the 12a that previous mentioned. 12a will mix with r12 and r134a but it is illegal here in the states. 12a runs at lower pressures and is colder then 134a. Im going to convert my stuff over to 12a when I get the money.

jtanguay seems to knows his stuff. I learned lots from him.

zukgod1 · « **Reply #7 on:** July 23, 2008, 06:49:51 am »

I think you have that bass ackwards.

134a isn't illegal. 12 is.

burnt_servo · « **Reply #8 on:** July 23, 2008, 08:07:19 am »

i run r12a in my car ..... got a slow leak some where , so every summer i need to add a few cans of the stuff ......

find the sight glass on your car ( it should be on or near the passenger shock tower )

with the car running and ac turned on , confirming that the ac pump is turning over , keep adding cans of r12a , untill the bubbles just start to disapear . ( roughly 2 to 3 cans worth most of the time for my car ) .

r12a works better at a slightly lower pressure than r12 , so more isn't nessisarly a good thing .

you may also want to add some leak sealer too

Possum79 · « **Reply #9 on:** July 23, 2008, 09:52:18 am »

Mixing the two is illegal. I know r-12 is illegal without a license.

zukgod1 · « **Reply #10 on:** July 23, 2008, 11:03:31 am »

Mixing the 2 isnt illegal..

I do suppose Cali could have put some other retarded law in effect though.

It's not recomended to mix them but it's that way for no other reason than the A/C shops want to charge for a complete flush and reseal job.

Possum79 · « **Reply #11 on:** July 23, 2008, 11:57:27 am »

Well someone told me it was a federal thing that your not supposed to mix but maybe it is just cali. I do hate this state. :lol:

jtanguay · « **Reply #12 on:** July 23, 2008, 03:04:24 pm »

well the keyword is hydroscopic, and that is why it is a good idea to flush your system out. the old a/c oil is hydroscopic, meaning it absorbs quite a bit of moisture, then turns acidic eating the system from the inside. if you leave the system open to the elements, it won't be long before it turns acidic. that is why there is a receiver drier in the loop. its just filled with a bunch of silica gel to remove the moisture.

so if you flushed your system (you dont really need to, but is a very good idea to get that old crap oil out) then use duracool's a/c oil chill, or another brand that is NON hydroscopic to avoid that problem in the future.

now back on track to the main problem. if your a/c isnt working you need to make sure that the clutch is kicking on. it is a very obvious click and so it is easy to detect. if it isnt kicking on, then you need to make sure that the low pressure cutoff switch has good contact with the two connectors going to it. (the low pressure cutoff switch is the smaller of the two sensors. it should be two thin green wires going to it. the other one is a high temp switch that kicks the rad fan into high speed mode when it gets too hot) wire brush the connections if you need to. mine kept falling off :roll: so i used a tie strap on the wire to keep it on. i think the system needs a minimum pressure of about 10-15 psi. just a safety measure that saves the compressor in the event of a leak. if your a/c still doesn't work at this point, and you're sure the gauge read above the 15-20 psi mark, then you can proceed to 'jump' the low pressure switch to override it. just pull the two connectors and connect them to eachother. you might have to pull back the plastic piece a bit.

if that doesn't get the system going, then it could be a fuse or relay. don't forget that the rad fan should be spinning when the a/c system is on! if it isn't, you will get cooling for maybe 1 minute and after that the system will be heat soaked and not cool at all.

i've never tried that redtek stuff from ctire, just the duracool from walmart. (yep they sell it there now! cans for $14.99!!!!! and kit with hose & sealer is about $78 but i'm not sure if walmart sells the a/c oil chill yet)

afaik the redtek kit doesn't come with an a/c oil solution. it is a very good idea to charge the system with an oil. otherwise the compressor won't last long (even though the head temps with r12a are lower than r134a)

its the law up here in Canada that you're not to mix refrigerants. although it works perfectly and isn't as bad. not that i've ever done it, but i'm sure people are doing it out there. why have your system vacuumed and charged with r134a for about a month before it leaks out, when you can charge a can of r12a and it last for the same time or longer, and cost way less? could be just one of those recovery issues... and i think its good that they want to recover the old R12 junk because it has a lifespan of about 120 years in our atmosphere... destroying the ozone layer.