How cold? can stock AC get.

[flatire]

I put the A/C back in the 69.
I'm looking for ideas on how to get it colder.
It blows cold but not enough.
The drain hole is the size of a quarter.
The headed is close to the expansion box and the fan squeeks at times.
I've got a stock type compressor.

If i fix all that crap will it cool the car?
Maybe it needs a good quality roof insulation too.
Humm couple hundred bucks and a day or so and I'll have the answer...

[71skylark3504v]

Have you checked your pressures yet?

[Smartin]

What refrigerant did you use to recharge the system?

[Joe65SkylarkGS]

My 95 Astro gets down to 39, 40 degrees.

Original 134 system. I'll get back to you on my 65 ac. I'll be putting the compressor in real soon.

[1967GS340]

Much like the leaded high octane fuel that many of our cars were designed to run on the juice of choice for your AC is a thing of the past and that can hurt the potential of the unit.
If you don't get the answers that you need here you should just stop into a radiator shop and talk to them. Most radiator shops that I know of do heater cores and AC also, so they may be able to tell you how yours is doing or what can be done to help it.

[austingta]

For today's 200.00 (actually fewer), go to Sears and buy a set of manifold gauges. Then go to a restaurant supply and buy a pocket kitchen inspectors (and manager's, we hope) thermometer.

Hook 'em up and report your findings. :Comp:

[No Lift]

I got a cheap set of gauges from Harbor Freight for around $45. I hooked my AC back up and needed something. They seem to be working fine.

[jerry455]

This thread reminded me of when I had the air system in my '72 Electra completely restored-
NEW AC Delco pump, all new hoses, reciever/dryer & everything.
I took it to this real "old-School" shop who specialized in custom A/C lines.
Well. they really loved the Buick-saying they don't make 'em like this anymore etc-
I filled it with the good stuff- FREON!
and that car read 32 degrees at the vent!!
The owners wife, a sweet older lady who helped out, said is was too damn cold to sit in it to take the temp reading!! she had to get out and shut the door during the test-
This was in late nineties- loved that car-

[austingta]

This thread reminded me of when I had the air system in my '72 Electra completely restored-
NEW AC Delco pump, all new hoses, reciever/dryer & everything.
I took it to this real "old-School" shop who specialized in custom A/C lines.
Well. they really loved the Buick-saying they don't make 'em like this anymore etc-
I filled it with the good stuff- FREON!
and that car read 32 degrees at the vent!!
The owners wife, a sweet older lady who helped out, said is was too damn cold to sit in it to take the temp reading!! she had to get out and shut the door during the test-
This was in late nineties- loved that car-

R12 is the BEST!

[Dale]

This thread reminded me of when I had the air system in my '72 Electra completely restored-
NEW AC Delco pump, all new hoses, reciever/dryer & everything.
I took it to this real "old-School" shop who specialized in custom A/C lines.
Well. they really loved the Buick-saying they don't make 'em like this anymore etc-
I filled it with the good stuff- FREON!
and that car read 32 degrees at the vent!!
The owners wife, a sweet older lady who helped out, said is was too damn cold to sit in it to take the temp reading!! she had to get out and shut the door during the test-
This was in late nineties- loved that car-

:TU:

When I had the AC on my '72 Electra gone over before a road trip to the Black Hills, SD, there was an old timer at the shop that worked on it.
When I picked it up at the end of the day he was just ecstatic that he was able to get 34* at the vent. http://www.clicksmilies.com/s1106/huepfen/jumping-smiley-017.gif

He wouldn't let me leave until he proved it to me.
"Try that with that R134 Sh*t! It was a pleasure to work on an old car with an R-12 system!" he said.

I had to agree with him, it was a pleasure flying down I-90 at 80+mph, in 100* heat, while riding in meat locker cold comfort!
:bglasses:

[Jeff Corey]

There was this old timer car salesman I heard tell of that picked up a car @ an auction and on the way back home with it dropped by the liquor store and bought a 6 pack of beer. He claimed the A/C worked so well on the 30 mile drive back home with the A/C blasting out the chills.......that 3 of the bottles froze and broke! Now is that a tall tale or what? LOL!

[austingta]

Yes. Yes, it is.

:beer

[BuickBuddy]

Hers' how cold mine got at idle.. Was about 5 degrees cooler at speed. :TU:

http://users.ntplx.net/~gkitty/Temp.JPG

[BUICKRAT]

Things that make an ac blow cold (assuming pressures/fill is corret,compressor is working and poa valve works):

Good fan shroud

Properly working fan clutch

No air leaks in A/C boxes/heater box(inside and out) If the A/C lines going to the evaporator have gaps around them or the insulation has shrunk away, replacing it will will make a HUGE improvement.

Heater control valve working properly

Correct vacuum to appropriate diverter doors

Doors move freely and seal as designed

Ductwork is intact and seals as it should




In my opinion, GM has crappy AC. Fords will freeze you right out of the car. I hate Fords but they have the BEST A/C in the world.

Make sure the charge level is correct. The only way to properly do this is to evacuate the system, vacuum test it for leaks, and charge with the specified amount of refrigerant. Only then can you test the rest of the system for proper operation. Low side pressure should be able to go as low as 32 psi. high side pressure should be 100-125 plus ambient temp. So on a 100 degree day, high side should be 200-225. Add 50 psi if using 134a

Just a start. I could go on for a long time, but dinners done

[71skylark3504v]

My A/C has been recently gone over. New compressor, expansion valve, POA valve calibrated for 134, but all I can get is just a cool breeze on a hot day.

Is it possible I need a new condensor?

[austingta]

My A/C has been recently gone over. New compressor, expansion valve, POA valve calibrated for 134, but all I can get is just a cool breeze on a hot day.

Is it possible I need a new condensor?

http://www.buickperformance.com/ac.htm

[71skylark3504v]

http://www.buickperformance.com/ac.htm


Been there done that, My A/C still sucks. The condenser, muffler, some hoses, and evaporator are the only things that haven't been changed.

On 75* days it will freeze your butt off, but 85-90* it doesn't cut it.

That leads me to believe the condenser isn't working correctly.

The A/C worked the same with the old R12 system as it does with 134 and the new parts.

[jkaz0442]

When I charged the AC on my '72 olds with R12 I got 14* at the vent with a digital pyrometer!! Nothing cools like the R12, I'm just glad I got a life time supply stashed. JKaz

[BUICKRAT]

My A/C has been recently gone over. New compressor, expansion valve, POA valve calibrated for 134, but all I can get is just a cool breeze on a hot day.

Is it possible I need a new condensor?

It is possible, but not probable. The condensors job is to remove btu's from the refrigerant. If the fins are corroded and falling off, then yes, you need a new one. If not, make sure all the airflow is going through the condensor. That means the right shroud, correct fan, and good sealing between the condensor and the radiator.

Pressure readings sure would help.

[Dale]

I recall as a kid, the metal vanes on the center AC vent of Dad's '64 LeMans would develop frost on it.

I've never cracked open the system on the '70 Riv, nor added anything to it, but the last time I ran it after rebuilding the engine it was still very cold.

[71skylark3504v]

It is possible, but not probable. The condensors job is to remove btu's from the refrigerant. If the fins are corroded and falling off, then yes, you need a new one. If not, make sure all the airflow is going through the condensor. That means the right shroud, correct fan, and good sealing between the condensor and the radiator.

Pressure readings sure would help.


It already has terrific airflow. What I'm thinking that in the past a compressor blew and set metal chips into the condenser. It did have a rebuilt compressor when I got it. Although it flows free through the condenser tubes it still may have a hot spot that would screw things up. Oh well, what's another $150? Might as well throw one in.

[lsrx101]

Guys,
I don't want to pee on anyones parade, but I really need to call BS on claims of anything less than about 35-38* at the vents. The posted claim of 14* is absolute nonsense unless he is talking Celsius.(57*F).
The coldest the evaporator itself can possibly get is 31-32*F or it would turn into a block of ice with any amount of humidity in the air at all. A more realistic figure for evap temp is about 34-36* with low airflow. Even at that temp, the air blowing across the evaporator cannot possibly be cooled to that point. It's not in contact with the evap long enough to cool to that temp as it flows through. The air will also pick up latent heat from the ductwork.
The GM/Frigidaire POA system is probably the best mobile AC system ever installed on a motor vehicle, but it simply cannot overcome the basic laws of thermodynamics. In real life, the very best you will ever see at the vents is High 30's to Low 40's on ANY mobile AC system.
BuickBuddy's pic shows a very realistic expectation of vent temps, although it can be a 5-6* colder at cruise, assuming that everything in the air distribution system is working as it should.

71skylark3504v,
Have you ever opened up the evaporator case and cleaned the dirt and debris out? It's really common for the evap to get plugged externally with dirt and restrict airflow. Also, over time the seals on the doors in the air distribution system deteriorate and allow heat from the heater core to flow into the cooled air, thus reheating it. Try clamping off the heater hoses and see if that helps.
The old single pass condenser is the weak link if you are using R134a, but it can be made to work reasonably well without swapping in a newer style condenser. If you feel a cold/frosted spot on the condenser, that is a restriction. Also check the high side lines and dryer. They should all be hot to the touch right up to the expansion valve. If you feel a cold spot, there is a restriction.

[71skylark3504v]

Guys,
I don't want to pee on anyones parade, but I really need to call BS on claims of anything less than about 35-38* at the vents. The posted claim of 14* is absolute nonsense unless he is talking Celsius.(57*F).
The coldest the evaporator itself can possibly get is 31-32*F or it would turn into a block of ice with any amount of humidity in the air at all. A more realistic figure for evap temp is about 34-36* with low airflow. Even at that temp, the air blowing across the evaporator cannot possibly be cooled to that point. It's not in contact with the evap long enough to cool to that temp as it flows through. The air will also pick up latent heat from the ductwork.
The GM/Frigidaire POA system is probably the best mobile AC system ever installed on a motor vehicle, but it simply cannot overcome the basic laws of thermodynamics. In real life, the very best you will ever see at the vents is High 30's to Low 40's on ANY mobile AC system.
BuickBuddy's pic shows a very realistic expectation of vent temps, although it can be a 5-6* colder at cruise, assuming that everything in the air distribution system is working as it should.

71skylark3504v,
Have you ever opened up the evaporator case and cleaned the dirt and debris out? It's really common for the evap to get plugged externally with dirt and restrict airflow. Also, over time the seals on the doors in the air distribution system deteriorate and allow heat from the heater core to flow into the cooled air, thus reheating it. Try clamping off the heater hoses and see if that helps.
The old single pass condenser is the weak link if you are using R134a, but it can be made to work reasonably well without swapping in a newer style condenser. If you feel a cold/frosted spot on the condenser, that is a restriction. Also check the high side lines and dryer. They should all be hot to the touch right up to the expansion valve. If you feel a cold spot, there is a restriction.

I don't believe the doors are the culprit since when I move the lever over, I get a nice thud. However, it seems I have decent airflow out the vents but I guess dirt could be causing it to not be cool.

[12lives]

If I remember correctly, GM keeps the heater core hot and regulates temperature using the doors and balances the flow with the manual controls or the automatic climate control. In any case, you've got a big heat load sitting just 1/4 inch of plastic away. Add 90+ outside temp and its a challange to get it to work. As isrx101 said, bypass or clamp off the heater core and see if that helps. Then you can tell how much warm air is coming from the heater!

-Bill

[BUICKRAT]

If I remember correctly, GM keeps the heater core hot and regulates temperature using the doors and balances the flow with the manual controls or the automatic climate control. In any case, you've got a big heat load sitting just 1/4 inch of plastic away. Add 90+ outside temp and its a challange to get it to work. As isrx101 said, bypass or clamp off the heater core and see if that helps. Then you can tell how much warm air is coming from the heater!

-Bill

Buick, and most gms, have a heater control valve that shuts off the coolant flow to the core when the ac is turned on. If the valve is not working, the ac will not get very cold.

[71skylark3504v]

I took the blower resistor off and my evaporator is as clean as can be. However, I noticed that my condenser still isn't working for some reason. The temperature of the outgoing refrigerant is just about the same as the incoming line. For some reason, air flowing through it just wasn't cooling it down. :puzzled:I took a garden hose and hosed down the condenser and that seemed to cool the outgoing line, and my vent temps improved.

[Golden Oldie 65]

A/C is a must here in Florida so you need all the help you can get. I installed some simple in-line shut-off valves in both the heater hoses in my `65 Skylark so I can shut off the coolant supply to the heater core for the summer, or rather, spring, summer and fall and open them up in the winter if I need them. I got them at Carquest. The part numbers are 277950 and 277951 for the 5/8" and 3/4" hoses.

Secondly, since R-12 is getting so hard to find and expensive, I switched to Freeze-12. I realize that many say this stuff shouldn't be used but it works just as well as R-12 in my system and it blows about 44-46 in town at the vents, dipping to 37-38 on the road on the open road and I haven't had any problems with it whatsoever. No changes are needed to the system to install it but I did evacuate my system free of the R-12 before installing the Freeze-12.

Bill

[lsrx101]

A/C is a must here in Florida so you need all the help you can get. I installed some simple in-line shut-off valves in both the heater hoses in my `65 Skylark so I can shut off the coolant supply to the heater core for the summer, or rather, spring, summer and fall and open them up in the winter if I need them. I got them at Carquest. The part numbers are 277950 and 277951 for the 5/8" and 3/4" hoses.

Secondly, since R-12 is getting so hard to find and expensive, I switched to Freeze-12. I realize that many say this stuff shouldn't be used but it works just as well as R-12 in my system and it blows about 44-46 in town at the vents, dipping to 37-38 on the road on the open road and I haven't had any problems with it whatsoever. No changes are needed to the system to install it but I did evacuate my system free of the R-12 before installing the Freeze-12.

Bill

Sweet valves 'Oldie! Many folks are looking for something like that to put in the heater hoses.

Freeze12 can work very well. It's just R134a with some R142b added to carry the old mineral oil through the system. It will work just as well as R134a, but not better. It worked around the problem of r134a not being able to carry the old lubricant through the system.
It's not inherently "bad" stuff at all. It had a place when the last R12 systems started springing leaks, when still fairly new, for a quickie "conversion".
The issue with using it now is that the newest R12 systems are at least 16 years old. The ones we talk about here are 30 or more years old and should really have some PM to be reliable. Most need much more that an evac and recharge.
Using FR12 now you are still relying on very old seals and a desiccant that is a potential time bomb waiting to go off in your system. It's kind of like putting gas and oil into a car that's been sitting for 20 years and just driving it. It may run just fine for a while but will likely have problems down the road without some initial PM.
If you were to open the system to replace a component, receiver/dryer or adjust the POA valve for R134a, it would be silly to use FR12 and mineral oil instead of r134a and Ester oil.

[Dale]

=
Freeze12 can work very well. It's just R134a with some R142b added to carry the old mineral oil through the system. It will work just as well as R134a, but not better. It worked around the problem of r134a not being able to carry the old lubricant through the system.
It's not inherently "bad" stuff at all. It had a place when the last R12 systems started springing leaks, when still fairly new, for a quickie "conversion".

5 yers ago when I bought the '92 Park Ave., the AC didn't work. It seemed to just peter out after I bought it.
So I took it in to have it looked at.
Well, after being given an estimate of $2,000 to fix it, I bought a few cans of Freeze 12. What the heck.

It still blows nice cold air 5 years later! I never have added anymore to it.

[lsrx101]

5 yers ago when I bought the '92 Park Ave., the AC didn't work. It seemed to just peter out after I bought it.
So I took it in to have it looked at.
Well, after being given an estimate of $2,000 to fix it, I bought a few cans of Freeze 12. What the heck.

It still blows nice cold air 5 years later! I never have added anymore to it.
Is that the car in the pic? Niiice.
Your car probably has a leak around the compressor body seal, really common on those. While they often get worse quickly here in the salt belt, I've seen them leak slowly for many years in a less corrosive environment. When you have to top it off again, just add a couple of ounces of mineral oil to keep the level up.
As long as it keeps holding, keep on using FR12 in it. It will eventually get worse, but...hey...

[No Lift]

I believe that the vacuum controlled switch in the heater hoses only turns the flow off when the MAX position is activated. At that point you're looking for max cooling. Any other position keeps the hot water running through the heater core so that you can regulate the temp to something above cold. I know when I'm cruising down the highway in my '76 on a warm humid evening it can get too cool in the car. You want to dry out the air and you want some air flow but you don't want it very cold so I turned the heat control slightly to the warmer side with the blower in the middle position and it worked great.
The valves in the heater lines sounds like the way to go in an area where it stays warm most of the time to positively shut off the heater. Actually it sounds like the way to go for a non-ac car that you want to make a little cooler driving around in the summer. It would keep the heat from even getting into the drivers compartment.

[austingta]

On older GM cars, the MAX position closed the fresh air ducts and recirculated the cabin air.

[Dale]

Is that the car in the pic? Niiice.
Your car probably has a leak around the compressor body seal, really common on those. While they often get worse quickly here in the salt belt, I've seen them leak slowly for many years in a less corrosive environment. When you have to top it off again, just add a couple of ounces of mineral oil to keep the level up.
As long as it keeps holding, keep on using FR12 in it. It will eventually get worse, but...hey...

That's my '96 Riviera.
My Stepson now drives the Park Ave. :pray:

[lsrx101]

That's my '96 Riviera.
My Stepson now drives the Park Ave. :pray:

I thought that was an awfully pretty Park Ave.:laugh: Now that I know and look close, it's obviously a Riv.:Dou: Duh.

I have 2 new drivers in the family, I know how you feel. Here, this may help::beer

[71skylark3504v]

My temperature control lever is supplying vacuum to the water valve all the time, even when it's on cold.:af:

[jamyers]

Good info above, here's my $.02 worth:

* I suggest that you head over to www.ackits.com and check out their forums -excellent tech info there. For example, here's a good thread covering a guy with an old Riviera, and how he adjusted his POA and got better a/c performance (http://www.autoacforum.com/messageview.cfm?catid=20&threadid=6974).

* A/C system performance depends on a lot of things like ambient air temp, airflow, pressure, etc. IIRC, if you get near or below 45 degrees at the vents you're doing well (that's on 'max', high idle with doors open.) I don't know what my old R12 system blew, but the R134a conversion I did blows 37-44 degrees in 90-degree weather.

* Don't waste your money on a 'rebuilt' or 'remanufactured' compressor, spend the extra on a good NEW one from a reputable source and be done with it. Too many places do shoddy 'paint-n-ship' work when they 'rebuild', and it's just too expensive (time and money) to evacuate the system, remove a dead compressor, flush the system properly, replace any parts that got plugged with compressor bits, install a compressor, pull a hard vacuum, check for leaks, install a new receiver/drier, pull another hard vacuum, recharge with refrigerant, then check to see if everything actually works. It's cheaper in the long run to spend the money up front - been there done that.

* Old GM a/c systems like ours (POA / Expansion valves, A6 compressor) are awful hard to beat, and from a design standpoint are arguable FAR superior to modern Cycling-Clutch, Orifice-Tube (CCOT) systems. R12 is a far superior refrigerant (over everything else out there), that's why it was chosen back then when a/c system performance was the driving factor behind a/c system design (instead of modern concerns like mileage and environment).

If I had a decent source of affordable R12, I'd have replaced/upgraded the old hoses (just because) and stuck with it. But I didn't, so I converted to R134a and am happy with the results.

As far as converting to R134a:
* Remove all the hoses and flush, flush, and flush the system. Lacquer thinner works well. Then flush everything again. You must get ALL of the old oil and any trash out of there.
* Replace the hoses - R134a has smaller molecules and will leak out of R12 hoses, especially old ones
* R134a 'wants' a bigger or more efficient condenser (different thermal characteristics) than R12, although our old tube-n-fin condensers are often large enough to work well. If you want a better condenser, get a TRUE "parallel-flow" condenser, they're about 30% more efficient. But keep in mind that if you EVER have a compressor failure, the condenser often becomes the filter and plugs up, requiring replacement. GM makes a filter that goes between the two for just such an event. Ackits.com sells both PF condensers and the filter.
* POA valve will want to be re-adjusted for R134a - this is something you can do pretty easily yourself if you have an air compressor. I forget exactly how, but there's a how-to at ackits.com (http://www.autoacforum.com/messageview.cfm?catid=20&threadid=16311). Basically, you adjust a nut inside the end of the POA valve to get a target pressure reading.

Don't mean to sound like a commercial for ackits.com, but every time I research mobile a/c parts and stuff they come up as the best source of info and quality parts at good prices.

[Golden Oldie 65]

Sweet valves 'Oldie! Many folks are looking for something like that to put in the heater hoses.

Freeze12 can work very well. It's just R134a with some R142b added to carry the old mineral oil through the system. It will work just as well as R134a, but not better. It worked around the problem of r134a not being able to carry the old lubricant through the system.
It's not inherently "bad" stuff at all. It had a place when the last R12 systems started springing leaks, when still fairly new, for a quickie "conversion".
The issue with using it now is that the newest R12 systems are at least 16 years old. The ones we talk about here are 30 or more years old and should really have some PM to be reliable. Most need much more that an evac and recharge.
Using FR12 now you are still relying on very old seals and a desiccant that is a potential time bomb waiting to go off in your system. It's kind of like putting gas and oil into a car that's been sitting for 20 years and just driving it. It may run just fine for a while but will likely have problems down the road without some initial PM.
If you were to open the system to replace a component, receiver/dryer or adjust the POA valve for R134a, it would be silly to use FR12 and mineral oil instead of r134a and Ester oil.

About 2 1/2 years ago I had the system open to upgrade the rest of the car (engine, trans, rearend, suspension, disc brakes, quicker steering, pretty much eveything mechanical was upgraded). It has factory a/c with an A6. Everything worked fine up to that point but when I put it back together the compressor was noisy so I replaced it with a remanufactured unit. I hope the reman unit has modern seals in it. As long as I had it apart I also replaced the POA, expansion valve, and dryer and put new seals in most everything, except at the condenser. I replaced the oil with fresh esther oil and evac'd it for about 30 minutes or so. So far so good. No complaints with the Freeze 12.

Bill

[lsrx101]

About 2 1/2 years ago I had the system open to upgrade the rest of the car (engine, trans, rearend, suspension, disc brakes, quicker steering, pretty much eveything mechanical was upgraded). It has factory a/c with an A6. Everything worked fine up to that point but when I put it back together the compressor was noisy so I replaced it with a remanufactured unit. I hope the reman unit has modern seals in it. As long as I had it apart I also replaced the POA, expansion valve, and dryer and put new seals in most everything, except at the condenser. I replaced the oil with fresh esther oil and evac'd it for about 30 minutes or so. So far so good. No complaints with the Freeze 12.

Bill

Oh! You pretty much rebuilt the system? Good Job! You can't beat a fully functional POA system with an A6 compressor for performance. Enjoy!


The Freeze 12 will work just fine as it's basically R134a. It was just unnecessary because you changed the oil to one compatible with R134a. There's no longer any mineral oil for the R142b to carry, so it's just along for the ride. No issue there.

Your new A6 will have all modern HBNR rubber in the case seals and the old style ceramic shaft seal. The ceramic shaft seal will work fine with R134a but you may eventually get the age old oil slinging issue from around the clutch. GM always claimed some oil slinging was "normal", but they never specified how much was too much. A new double lipped rubber seal can be retrofitted to the A6 to prevent it but there's no need unless the ceramic seal fails. I don't know of any manufacturer that installs the lip seal in their units. Keep it in mind for future reference.

[Golden Oldie 65]

Thanks, I'll do that. So far I've seen no oil on the compressor, but then again nothing lasts forever.......does it? :pray:

Bill

[No Lift]

The compressor on my '76 Century seems to be slinging oil out of the clutch area and it seems to be excessive. Can that double seal be fitted to the compressor while the unit is still charged? I have a clutch removal tool and service manual so I'm half-way there.
If it can't I just have to install one of those shields that GM had on some of the cars. Now I know that it was there just to keep the oil from flying all over the place.

[lsrx101]

Unfortunately the system must be discharged before replacing the seal.
Yep, those shields were used on the higher line cars to catch the oil.

[lsrx101]

Good info above, here's my $.02 worth:
...About 3 tons of excellent info edited for brevity. :TU::TU:...


Please read jamyers post above and take it to heart if you want to properly repair the ac on your Buick!
When it comes to your AC system, there are usually no money saving shortcuts. It's a precision system and cutting corners often results in disappointment or failure.
I've seen folks spend large amounts of money restoring a classic car with no questions asked, only to balk at a few hundred to restore the AC. They've spent 10-15K or more on the car,but choke at $3-500 to correctly repair the AC (if even near that much)??
I'm always puzzled by that.:Do No:

[jamyers]

...They've spent 10-15K or more on the car,but choke at $3-500 to correctly repair the AC (if even near that much)??
I'm always puzzled by that.:Do No:

Thanks for the kind words! I learned about not scrimping-out on a/c the hard way. In the long run, it's cheaper and easier to do it right the first time. Heck, I just went halfsies with my bro-in-law on a MasterCool vacuum pump that'll pull down to something silly like 50 microns (better than 29.9 inches of mercury vacuum) for $120 delivered, that piece of equipment will pay for itself the next time I use it.

And I'll add that anybody reading these words can do a better job than about 90% of the a/c shops out there - it ain't rocket science, but you gotta care about what you're doing and want to do it right.

:beer