Safely Discharge A/C System

[Dignan]

I thought that it would be easy to find on here, but after searching I can't find anything. How can I discharge the pressure so that I can start replacing parts? I assume most systems are similar, but mine is a 2002 Mountaineer with a V8.

Thanks

 

[Maniak]

Well, Safely, and legally aren't the same thing here.. Legally, you need to take it to a shop to have the the r-134 reclaimed.

Safely just means just don't open the system up quickly. You could use the gauges and just vent it slowly, but that is not legal.

~Mark

 

[Dignan]

What is the going rate for a shop to do that?

 

[Maniak]

I haven't had a shop recover the freon in a few years. It used to be free as they kept the old stuff. Of course by now, I expect shops to charge you to give them stuff.

~Mark

 

[Dignan]

Ha ha, probably right about that. I have a leak, so it is probably all gone anyway, but maybe I'll check with a shop to be safe.

 

[Maniak]

If you have gauges (I'm assuming you do), just hook them up and look at the pressures. If there is no pressure, its already gone. If there is pressure, do the safe and/or legal thing.

~Mark

 

[Dignan]

Actually I don't have gauges.

 

[Maniak]

Your going to need them so you can charge the system.

You can get a set of gauges and an electric a/c vacuum pump from Harbor Freight tools for < $200. That way you can evacuate the system (not recover the old stuff, but evacuate the system before you charge it) yourself and charge the system yourself. r-134 is running for "around" $12-$18 per 12 ounce can (I bought my last case for $10/can last spring).

There is a sticky thread about charging the system in this sub forum. its a good read. Charging the system actually isn't that hard to do once you know what your trying to do.

~Mark

 

[Dignan]

This thing?

 

[Maniak]

Yup, That the gauge set.

Here is the pump.. http://www.harborfreight.com/25-cfm-vacuum-pump-98076.html. They make a better pump but if your not going to be doing this often I wouldn't spend the extra money for the extra 1/2 cfm.

~Mark

 

[Dignan]

crap. $200 worth of tools and $400 worth of parts... I might just take it to a shop.

 

[Maniak]

crap. $200 worth of tools and $400 worth of parts... I might just take it to a shop.

If you take it to a shop, add another $500+ to the cost plus you won't own the tools for next time you need to work on a/c.

~Mark

 

[Dignan]

Yeah, you're right. I hate it, but you're right.

 

[Dignan]

So, considering I found a tennis-ball-sized hole in the side of the compressor, I think the pressure has been released. So, my plan is to replace the compressor (obviously), and the orifice tube while I have the pressure out. Then compare the cost of paying to have it recharged to buying the tools we talked about. Probably buy the tools to appease the natural need to accumulate tools, but I am cheap too, so we'll see.
So I have two questions for the A/C experts.
1. I was afraid I might have black death, but since it appears the compressor exploded instead of melted, that is unlikely, right? (I guess I'll know for sure when I swap out the orifice tube).
2. Is the above mentioned plan the way to go? Is there anything else that I should do?

Thanks guys

 

[Maniak]

You'll know if you got black death when you pull the orifice tube. However, having the side blown out of the compressor is a little scary BUT it does mean there is no pressure.

Since the system was open like that you should replace the accumulator (receiver/dryer). Most compressors require you to do that or you void the warranty anyway.

Also, since your in Tx, See if you can find a variable orifice tube. They give you a higher idle pressure differential so it will help the cooling at idle. They work much better than the normal orifice tubes, especially in how climates.

and my opinion is still, evacuate and charge the system yourself. Once you do it a 2nd time you should be ahead of the game. I'd expect them to charge you $20-$30 per 12 ounces of r-134 AND $20-$100 to evacuate and charge the system. On top of that, if you still have a leak and they don't catch it during the evacuation procedure your still going to be on the hood for their labor and r-134.

~Mark

 

[Dignan]

I agree about the variable orifice tube. Will do. I was looking at parts on www.discountacparts.com and they have a rebuilt compressor for 195, an accumulator/dryer for 45 and they didn't seem to have a variable orifice tube, but I can pick that up locally.

Also, very good point about if I have a leak after they fill it. I will likely buy the gauges and vacuum, but its going to have to wait. I have too much going on right now to fork all this out. It is over 100 degrees every day, but people have suffered worse conditions than not having A/C in their car, I can hang tough for a while.

 

[scucci]

If you need the gauges and pump here is a deal n a decent set:
http://www.wholesalepartsandtools.c...15_Brass_R134a_Manifold_Gauge_Set-763-87.html

 

[Jason94sport]

You need to flush it before you put vacuum on it.(may need to do it 2 or 3 times) If you don't your new office tube will clog with debris cause a restriction & never work right. I know, that's what happened to me. And if your compressor had that damage you can bet there's all sorts of junk through your lines & condenser. Again was on mine & my compressor seized.
Also replace the the accumulator.
So the steps are..
Take out parts
Flush the condenser
Flush the lines
Flush the evaporator
Install new parts(with all new o rings, even the lines)
Put vacuum on it let it run about a hour
Turn off & let it sit, holds vacuum & doesn't drop your good, looses vacuum not good
Add 134 & recharge
Also don't forget the oil. 1 oz in the accumulator, 2oz in the compressor(unless it comes pre-oiled, it will say so) 1 oz in the condensor