AC charging questions

[Sonny]

My final part (condenser) just arrived for my ‘70 Belvedere. I’ve replaced:
-Compressor (reman for new r134a)
-evaporator and core
-dryer
-clutch
-expansion valve
-I cleaned the original hoses with ac flush.
-replaced all o rings with green ones.

Question: can I charge the system using a $50 can (or 2?) from a parts store or should I take it somewhere and let them do it for $129?
I have not tested the system for leaks and don’t have the tools to do so.
Thoughts?

 

[mccoymail]

needs to be vacuum evacuated first. Spend the $129. Or shop around; mine was $89.

 

[PurpleBeeper]

Yeah, I'm with McCoy on this one. Have it professionally vacuumed before re-charging and IF POSSIBLE, see if they can put some red dye in there. That way, if you do have a leak somewhere you can see/repair it yourself. The dye in the system won't hurt a thing.

 

[Sonny]

Yeah, I'm with McCoy on this one. Have it professionally vacuumed before re-charging and IF POSSIBLE, see if they can put some red dye in there. That way, if you do have a leak somewhere you can see/repair it yourself. The dye in the system won't hurt a thing.

If all the components are installed and system sealed, can I now attach the drier? Can I safely test the clutch without first charging the system? Hook up leads to the drier? Might be a week or so before getting it charged.

 

[mccoymail]

Had mine installed for about a year before charging. I’d say you’ll be fine.

 

[493 Mike]

You say the system is sealed, so is the old R/D installed? The R/D will suck up any moisture in the system so T would install it just before evacuating the system to keep the desiccant as fresh as possible. Did you flush the system with one of the products available for that purpose? You don't want any junk or moisture in a A/C system.
Mike

 

[Demonic]

^ This. Check your condenser inlet tube as far as you can see. Be careful with the aluminum threads if that's how yours is, they gall easily. Use light mineral oil sparingly on the threads. Consider having your hoses redone with barrier type hose, R-134 is "smaller" than R-12 at the molecular level, so it leaks through easier. Find a commercial HVAC guy with nitrogen, a regulator and a gauge set, use it to pressure test the system. Get spare o-rings. As Mike said, the filter-dryer desiccant will suck moisture out of the air.

 

[Sonny]

^ This. Check your condenser inlet tube as far as you can see. Be careful with the aluminum threads if that's how yours is, they gall easily. Use light mineral oil sparingly on the threads. Consider having your hoses redone with barrier type hose, R-134 is "smaller" than R-12 at the molecular level, so it leaks through easier. Find a commercial HVAC guy with nitrogen, a regulator and a gauge set, use it to pressure test the system. Get spare o-rings. As Mike said, the filter-dryer desiccant will suck moisture out of the air.

I left the dryer unhooked and capped. What I meant to say was once I hook it all up tonight it will be a sealed system. I replaced the entire system except for the hoses. I did clean them And the hard line to the new dryer with the AC flush solution.

 

[493 Mike]

I left the dryer unhooked and capped. What I meant to say was once I hook it all up tonight it will be a sealed system. I replaced the entire system except for the hoses. I did clean them And the hard line to the new dryer with the AC flush solution.

Good procedure, just don't hook up the R/D until necessary for evacuation.
Mike

 

[Ranger16]

I have not tested the system for leaks and don’t have the tools to do so.
Thoughts?

That alone say's pay the money and have it done. You need a vacuum pump to test it as well as charge it.

 

[bearman]

If you have someone do the evac, pressure check and fill it fo the following to get a clean system. After the person installs drier pressure test it with nitrogen spray all connection to find leaks. Repairs leaks if any show up next evac the system and get all evac down to -30 on the gauges plus bring it on down to 500 micron this is a clean system plus if it won't go down to the 500 mark you still have a leak. Good luck

 

[Dennis H]

Shop. Have them check for leaks.

 

[WileE]

Like they said, you have to evacuate the system first and check for leaks, then introduce the refrigerant and oil. Let a pro do it.

 

[Cranky]

I wouldn't use the original hoses. Man, they are nearly 50 years old so make new ones instead. Like mentioned above, the 134 molecules are smaller than the old 12 stuff and need a better hose and for sure not ones that are 48 years old....

 

[wyrmrider]

agree with crank and others- new 134a barrier hoses- take your time- do it right
do not test run the compressor with no oil - what's in their will not circulate with no charge
you could put R/D in but why
there are inline filters throw one in before the compressor and b4 the expansion valve or what areyou using?
there is probably crap in the evaporator so filters
did you say new condenser? you know that 134 is not as efficient so put in the largest condenser that will fit and make sure the air flows through it

 

[JimKueneman]

If you use the old hoses the old mineral oil has permeated the old hoses over the years and seals the 134a. I cleaned my original hoses, put new 134a o-rings, evacuated and charged it. It is going on a year now and I use it all the time in Arizona. Still blows ice cold. I am still a believer that the OEM 50 year old stuff is still better than 99% of what you can buy today and use it until you can't!

 

[bearman]

Worked on a a/c thursday ,problem was cooling but at stop light not so good. Higher rpms ok but not great. Well evac system weighed out freon changed filter dryer. Also flushed the system basic a/c service. It was a converted r12 unit long story short after cleaning everything it worked really good. So what i guess I'm saying is make sure to service your system to keep it in good shape.

 

[72sunroof]

Worked on a a/c thursday ,problem was cooling but at stop light not so good. Higher rpms ok but not great. Well evac system weighed out freon changed filter dryer. Also flushed the system basic a/c service. It was a converted r12 unit long story short after cleaning everything it worked really good. So what i guess I'm saying is make sure to service your system to keep it in good shape.

Check pressure with gauges.
http://aircondition.com/tech/questions/82/Troubleshooting-with-Gauges-FAQ