A/C help please
 

Hi all. I have an issue with my daughter's 91 SSE. We had it retrofitted 2-1/2 years ago with R134a. Cost $1100, and has worked well until last week when it started squealing and rattling. Turned it off and have relegated the car to "city only" duty. I was given an $800 estimate by the same shop that retrofitted the car. I was going to try and save $ by buying and installing the compressor myself, but I have read posts here in the past about reman compressors that are not well made. I feel like I got a longer life out of the part than most. I would like to bypass with the "shorty belt" for daily service now (and if you have a part # that would be great). I have several questions. If I go to the wreckers to get a used one, what do I look for to be sure it is O.E.M? And the manual says to have the system discharged. How hard/dangerous is that for a shadetree guy like me to do. And do I need to replace the accumulator like the manual says? I am willing to pay to have the system recharged, but otherwise, I am looking for is a good project and a way to save my daughter some much needed money for college . Thanks

Well, you can have it discharged at some shop, I doubt you have the equipment to do it. the compressor is not that hard to replace as long as you have an FSM. And I would recommend getting one from a parts store. Reman is fine. Also, the instructions should come along with it. So there shouldn't be much concern. Also, what kind of manual are you talking about? an FSM or just like a Hanes or Chiltons?

The manual I was talking about was a Chiltons, and thanks for reminding me that I have a FSM. Doh!

I read a bit a few years ago about reman compressors. The complaint was geared towards the earlier R4 GM compressors manufactured by Four Seasons. On this forum, (Don't remember the URL, but was geared for auto AC) they called them "4 siezens" lol.

Having that in my memory, if I ever need an AC compressor, I think I will go with AC Delco/ Harrison.

Ok, now I will head to the parts house and check on gauges to discharge & recharge the system myself. And look for the AC Delco compressor. Thanks

SUCTION
 

Just remember when you crack the system open , such as to replace compressor, you allow air into the system, cant get by it! At the same time you should replace the accumulator, known as Reciever/Drier, this little piece of engineering does one thing only and thats to keep moisture from the freon, should moisture somehow still be present after a proper part replacement and freon install. Thats why you need a suction pump running 30 minutes to achive 29lbs vaccum, so as to eliminate all air from system and reduce 99% of any moisture as well. It also serves as a leak test, when you let it sit for about an hour, and it doesnt lose lose more than 1.5lbs of vaccum, this tells you all fitting, O rings, Lines are good, meaning everything is good sealing after parts replacement. then when you are ready to charge your system, it allows the gas to enter with no outside air contamination, Moisture is death to a amonia based freon system, as it combines with the freon, R-12, R134-A, and becomes very caustic, eats at the O rings lines, condensor, evaporator, ETC, you get the idea! You will hook up the pump through the manifold gauges, keep high side off, shut tight, suction through low pressure side, then after everything described, close low side gauge, keeping suction to the A/C system, then remove pump line, replace with freon delivery line, open freon gas just alittle from the bottle, crack the line leading to the manifold just a little, untill you hear gas comming out, for about 5/6 seconds, this purges the air out of the line that is delivering gas to the manifold, then retighten while gas is escaping, Now you are ready to recharge. Keep in mind that the compressor can only compress GAS! If you allow the freon to enter as liquid straight into the suction side directly to the compressor, you will blow the head on your new replacement compressor, If your bottle is verticle is comes out as gas, If you Turn it upside down it will come out as liquid. Also remember before you start the engine and engage A/C system, to bypass the low pressure shut down sensor, or the compressor clutch will not engage, therfore NO COMPRESSOR WORK OR PUMP/COMPRESS, ALL THE ABOVE! You can run the compressor for about a couple of minutes without freon, but as soon as you get it going, immediatly start introducing freon into the system, as this is part of what keeps a compressor cool, [Also remember to check replacement compressor for proper oil level fill before bolting on] meaning no overheat, bearing failure, as well as seizure. The rest is a bit much to explain, but in a nutshell, the amount of freon to add depends on the system requirements, but also your gauges give you all the info you need to charge it with the right amount of freon, also outside ambient temp can mess with a precise amount to go by. Keep in mind undercharged system poor cooling, overcharged system, poor cooling as well, meaning the just right amount is the sweet spot, YES their very temptermental. Like a woman! Your site glass should be on your new accumalator, when you see a solid flow with very little amount of bubbles, close the suction maniflod gauge tight and see how the air is blowing, It would be also best to try to rig the biggest fan you have or acouple of them blowing into the radiator, so there is air flow going past the condensor, otherwise Its hard to see how efficent your charge will be, as this needs air to radiate the heat from the freon in order to deliver the freon free of heat back to the evaporator and compressor for another cycle! Do your reading, then decide if this is for YOU to do. If not bite the bullet, pay the money to a reputable A/C service center, who only specialises in automotive A/C work. Hope this helps ya, and good luck with the project, Ive been in your shoes, and that why I got what I needed to do it, Its saved me a ton of money, not including repairing and charging my home 5 ton unit, R-22, but same principal and proceedure. Also some people say use the compressor to purge air out from the system, and create suction, But like I said its very hard on the compressor to do this and could damage it or create a premature failure, cause of excessive wear, I reccomend using a vaccum pump to do it right. :thumbup2:

Wow, now that is thorough. Thanks I will study this and proceed slowly.
Thanks for the help....

Didn't know if you were still wanting to get a shorty belt, but you should try looping a string over the pulleys and then tying it off at the proper length, subtract about a half inch or so to allow for the tension, and take it to your local auto parts store. They can usually help you find the right size belt by that.