Cheap Tester??

[Explorin94]

I answered the question in post #5. The problem came about later. I'm not out to prove anything to anyone. I think we've moved off track a bit here. By pop-off valve I take you mean the high pressure release valve. It shouldn't go off at all if everything is working right. When it does go off, it usually means there's too much pressure in a more or less properly charged system caused by excess heat. 9 times out of 10 it's because the fan isn't doing it's job, crud on/in the condenser, etc., but I digress. It isn't there to let you know that you've overcharged the system. By the time you've charged to the point where the valve releases, you are already way overcharged, especially if it releases during an engine off or compressor off type charging. A proper set of gauges used while charging will prevent you from ever reaching that point. I don't mean the ones the the auto parts store sells that only measure the low side. I try to discourage people from using what I feel are unsafe practices.

There ya go....well said. I see you changed your other answer to this. Yes I was reffering to the high pressure release valve when I said pop-off valve. They more or less do the same job.
Like I said some of the guys...or gals here like to attempt jobs on their own. Even though there is the possibility they can get hurt (and with some of these jobs they can get hurt very bad) but, that is where we step in and tell them the dangers of it. Like the above post you had....you explain what needs to be done and how they need to do it. Let them determine if they need to take it in.

 

[sblake01]

Well, I didn't really change my answer; I just expanded on it. I really didn't think anyone one wanted to hear me go on about it being unsafe and why. I recall a demo years ago in my AC class where an explosion was intentionally produced by overcharging to show how much damage is possible. It blew a hole in the hood. I know that's somewhat extreme but that picture kind of stays with you......It was weezl's resopnse that led to post #12 and 13, not yours. You know...egos on the internet

 

[--weezl--]

Well, I didn't really change my answer; I just expanded on it. I really didn't think anyone one wanted to hear me go on about it being unsafe and why. I recall a demo years ago in my AC class where an explosion was intentionally produced by overcharging to show how much damage is possible. It blew a hole in the hood. I know that's somewhat extreme but that picture kind of stays with you......It was weezl's resopnse that led to post #12 and 13, not yours. You know...egos on the internet

Oh, and by the way, I'm 61 years old. I've probably forgotten more about cars that most will ever know. I don't come to these websites for advice; it's worth what you pay for it. My day won't be screwed up if I don't get some anecdotal answer on a website and no one else's shoud either. Go ahead, tell me how you think I should answer on a web site. You really think it will make any difference??

forgotten more than most will ever know, which means that you remember what? seeing as a lot of people on here know a huge amount of technical information... if you've forgotten more than they know, that would leave you with... well peanuts...

honestly, i could care less how old you are... it makes no difference... my father's roughly the same age as you, he taught me half of what i know about vehicles... however now he comes to me to ask how to do stuff (though i still go to him for certain things that i hate dealing with, like electronics)

i totally agree that arguing on the internet is pointless, so is saying obnoxious things and generally saying things that people are likely to take offense to, which is what happened to post 10... honestly, the answer you gave in post 5 did not seem full, seeing as explorin asked for further details (post 4) and you got defensive...

as for egos, i agree, they aren't useful... my local 4x4 group has a zero tolerance policy for egos, if you are caught disrespecting someone because they have less knowledge in an aspect or less mods to their truck, or even because they get stuck a little more... you're done permanently... i've seen it happen a few times now... and that's how i take your comment of "i'm 61, i've forgotten more than most people have ever known" it seems to me like you're trying to prove something... we are all here to be friends, it just bothers me when someone gets their feathers ruffled because they gave half an answer and someone asks for more details, and how you know what you said is right...

 

[sblake01]

Can we please just let this go? I explained my position on my post to Explorin and he accepted it. And I never 'disrespected' you while:

Your quote:

what's with the snot ass attitude? what are you 12? grow up and answer the question if you want to act like the guy who knows what's going on
yes i said act... i can also claim to be a licensed technician... hell i can claim to be god... doesn't make it so

You and I were both 'out of line' to some degree but show me where I ever said anything like that directed personally to you....

 

[4.0B2]

i didn't read most of this...

what i would do, personally, is just pull a vacuum on the system and see if the guage moves overnight.. if the vacuum stays overnight, i'd throw some freon in it (w/ dye if you wanna be safe).

 

[sblake01]

That's most likely a good thing.....

If the vacuum holds overnight, you should be fine. I'm satisfied if it holds for an hour on my own vehicles and when I'm working on someone else's I give it two. The dye would be good for future testing if you have the uv light that goes with it. If the vacuum holds, however, there wouldn't be an immediate need for the dye.

 

[--weezl--]

how would you test it with a vacuum?

the a/c system is a positive pressure system, who's recharge valve is essentially a shrader valve... is it not? wouldn't a vacuum open the valve and draw in air?

 

[sblake01]

how would you test it with a vacuum?

the a/c system is a positive pressure system, who's recharge valve is essentially a shrader valve... is it not? wouldn't a vacuum open the valve and draw in air?

You draw a vacuum (roughly 28" hg. to 30" hg.) with a vacuum pump and a charging manifold, close both sides of the manifold (which will hold the vacuum in the system) and watch the gauges to see if and how long the vacuum holds.

 

[--weezl--]

oh, so the valve is open the entire time, and capped off by the gauge? essentially...

 

[sblake01]

That's how it works. The high side and low side hoses are screwed on to their appropriate valves (or snapped on in the case of R134a type fittings) and the vacuum pump is connected to the yellow (center) hose. When you close the ports on the gauge set it caps off everything.

 

[4.0B2]

oh, so the valve is open the entire time, and capped off by the gauge? essentially...

yes.

 

[kimcrwbr1]

Are you sure it has no refrigerant in it, carefully depress one of the schrader valves in on the service ports just be careful it is real cold. one ounce of refrigerant has the same pressure as one lb of refrigerant. If it has refrigerant in it it could just be low. You add refrigerant by weight not pressure. If the system is dead add just a little juice in it for the pressure test and soap test everything good (spray bottle with dish soap and water). Once you fix the leak you should take it to a shop to evac the system and add the charge. It has to be pulled into a deep vac so you dont contaminate the refrigerant with non combustable gasses and water. If it has pressure in it just add the correct refrigerant until the compressor turns on. You can bypass the pressure switch and add juice in until you get around 20 degrees difference between the air going into the blower and the air coming out inside the cab. Just dont run it very long under low pressure the refrigerant carries the oil into the conpressor. It there is any pressure at all it dont need to be evacuated it probably has a real slow leak. I would give it a charge and see how it works. If the system is dead you will need to diagnose the system especially since it has not been running the compressor seals can get hard.

 

[killj0y]

Don't do this! But I've seen people pressurize the system with a little air from a compressor and dye to find a leak. But I'm sure this introduces waaay too much moisture into the system and possibly ruining some components like the dryer.

 

[--weezl--]

not to mention it is very difficult to get that air back out, so even when it is recharged with the proper amount of freon/rg-whatever, it will run less efficiently

 

[4.0B2]

Wow I just realize how much I missed about my first comment on this thread lol.

Never put air in a system. It's a pain.. I wouldn't at least. I'll spend the money on dye and do it right.

On a side note; mine still works!!!! 2-3 months and it ain't leaked out yet