71Camaro350

My AC compressor froze up on me on my 94Z. I was thinking about doing the R&R myself as I have guages and a laboratory-grade vacuum pump. I've used the vac pump on a few R12 systems and they cooled very well, even in Austin summers.

I've heard various stories about needing to flush an AC systerm if the compressor locks. I can see the logic, if any vanes broke and went into the system, they could circulate around and seize up the new compressor.

So what actually goes into a flush? And do i really need to do so?

BTW, prior to the compressor lockup, it cooled well for an Texas Summer....

harnick3

I've never heard of an ac flush. The vac. should pull the foreign junk out. However someone on here might know something about it. If there is such a thing, be carefull of what you use to do it with.

Šenial™

A flush is just that... all it is, is basicly getting the vapors out so it doesnt mix with the refridgement, not only does it not make it as cold as it can get, but it will sieze it up also if theres alot in there.

throttlesteer

There are no "vapors" in the A/C lines as you suggest other than the compressed R134a Refridgerant. The reason you do a flush is either when you are converting to the new style R134a or the compressor had internal failure. On the 4th gen F-bods when the compressor locks up it is NOT possible to flush the condensor (the big heat diffuser in front of the radiator) completely. Most people replace it in this case but I"m sure there's a few out there that neglect the suggestion and try it anyway. It's your call on what you want to do there.

Also, when the compressor has internal failure and metal shavings are sent throughout the system, it clogs the reciever drier and orfice tube with these particles. With both of these easily replaceable parts clogged and you throw on a new compressor, it will burn the compressor up in a short time and it won't get cold inside the car.

The best thing to do is replace the Compressor, Condensor, Reciever/Drier, and orfice tube and then have a vaccum put on the system. The system should hold at least 25lbs of vaccum for 15min. If it doesn't, you've got a leak in one of your lines or seals. You don't necessarily have to replace them with brand new parts (except for the drier and orfice tube which are really cheap), but be wary of the junkyard compressors and condensors. There's no really good way for them to test these things and it's hard to tell if they're good or not unless you put them on your car and test them. Most of the time they're good at swapping in another one if you get a bad one though.

After you get the parts replaced make sure to refill it with the proper amout of R134a and Pag oil/Ester oil. Advance Auto Parts should have the spec for your vehicle listed in the computer. Hope this helps!

Šenial™

Actually, there are vapors that can get in the lines, when you are replaceing a compressor and have the lines disconnected after letting all the refridgement out, and are letting the lines hang there for 5 or however so minutes wile putting a new compressor in, what do you think is getting in the lines? Putting new refridgement right in the system without flushing out (connecting a vacume to it) will cause things to sease up if the lines were open for long enough, and definatly not be as cool as it could be

71Camaro350

I've heard that story about replacing the condenser when the AC compressor seizes.

HOWEVER, it appears that to replace the condenser, you have to take the whole nose off the car! I've not had a working windshield washer for nearly a year because to replace the pump, it looks like you once again, have to take the entire nose off the car. It looks like the way GM shoehorned stuff in there, if anything in the nose goes bad, its not hard to fix once you get the nost off!

So I guess I finally have two reasons to take the nose off. So how do you do it?

shoebox

You don't have to remove the nose to get the condenser out.

shoebox

No orifice tube in a 4th gen.

Blue89Bird

go away scammer

http://web.camaross.com/forums/showthread.php?t=465456

throttlesteer

To be honest I've never done one on a 4th gen. I'm speaking from experience on vehicles in general and not just the F-bodys.

Denial, believe what you want, I'm not going to stop you.

Ray86IROC

I flushed out all my A/C lines, the evaporator and condenser (first I've heard that you can't flush it well enough, hope it's not 100% true) when I redid my system. I did what was recommended on here and by the local shop that I wasted $100 on to tell me what I already knew about the system...

I removed all the parts I was not reusing (compressor, dryer, and expansion valve) and disconnected all the lines. I then used brake cleaner to spray into each line some and then blew everything out w/ my air compressor. Did it a few times on each part till it came out the other end clear. I also did this w/ the condenser and evaporator, seemed to flush out decently (my compressor hadn't truly fragged, just not working properly) so I hope this flushing worked just fine. You can imagine I made a fair bit of mess getting brake cleaner and pag oil that was left in the lines all over myself. You'll need to be creative to catch it effectively unless there is a flushing kit I'm not aware of... I had the best luck cutting a hole in the top of a tennis ball can and sliding it over the opposite side of the line I was flushing...

Then I reinstalled the new compressor, dryer, and expansion valve, adding a total of 8.5 oz of PAG oil to the system (a single can of oil, the non-compressed kind you just pour in), some in each main part and the rest in the lines and such. (instructions say to spin the compressor by hand after install to push out some of the oil) I then pulled a vacuum on the system for over an hour w/ the vacuum pumps Harbor Freight is selling for $10-$15 (venturi style pumps you hookup to your air compressor, according to my gauge it pulled like 25-30 inches or whatever the measurement of vacuum is on the system for that time), and then filled the system to the proper amount of refridgerant. Seems nice and cold and as far as I can tell with my cheap harbor freight manifold gauge set (on sale for $30) the pressures look good. Fingers crossed that this was effective and holds up...

BTW I used A/C parts from my local advance autoparts, rebuilt compressor for $200ish, exp valve was $40ish, dryer/accumulator thing was $55 I believe. 1 year warranty on the parts. Most around here would probably recommend the genuine GM compressor but I didn't really want to spend the extra $100+ dollars. Plus I figure being my first major A/C system work if the rebuilt compressor fails in a year it would likely be due to something I did wrong in the install that would have fragged the GM one as well. Time will tell (knock on wood).

2cub49

The condenser comes out the top after removing the sheetmetal plate that holds the radiatior down.
Mine was plugged with road crap that was also choking off the rad.
Got a new aftermarket one on ebay for 115.00 and after installing it the A/C was ice cold again.
I got my washer bottle out from underneath by pulling back the plastic shrouding. I think I cut part of one bracket with a sawsall to get a wrench in to get a bolt out.
It can be done without removing the front end.

throttlesteer

Ray86IROC, lets hope you didn't vaccum any oil out when you put the vaccum pump on the system. Usually when a shop puts a vaccum on an AC system it's to get all the contaminants and old oil out of the system. Which in your case, you could have vaccumed up some of the oil you just poured into the system. Sounds like it ended up pretty good for you though. Keep your fingers crossed.