DSMAddicted

Guys,
I've been doing insane reading on AC systems, getting ready for cabin filter retrofit, full flush, vacuum, recharge etc.

I think I have all the information needed to do the above. The only piece of information I seem to be missing right now is regarding the removal of old oil from the AC compressor.

In most threads on the topic, the AC compressor is being replaced with a used one or added (AC retrofit), so people usually mention removing the oil by putting the compressor upside down (let it drain out). Since I am fairly sure my compressor is still good (), I am planning on changing the oil for maintenance purposes and avoid removing the compressor from the car.

I have one of these and I use it very often to change the oil on lawn mowers and other small engines:

Oil Extractor

It's a very nice pump, works surprisingly well and I strongly recommend it.

My question is: those of you that have looked at both ports on our compressors... do the openings lead directly to a small tank inside, easily reachable by inserting the vacuum tube (same size of a brake wire from a bicycle)? Or are there passages and lines, meaning that the only way I can do this is by removing and draining upside down?

I have thought about measuring the amount of oil I pull and add the same amount in mL (adding a bit to make up for the empty dryer/evap/condenser - see this and this)... but I think it may be best to empty the compressor completely and add the recommended 120-140mL.

Can I get some brainstorming power from the AC experts?

Thanks!

deschlong

iTrader: (8)

Hmm, I dunno. Removing the compressor is 6 bolts (4 + 2 hoses), plus the belt tensioner. I'm of the mind that there are few opportunities where your A/C system is disassembled so it's important to do it right/by the book when you have the chance. Gives me peace of mind.

DSMAddicted

Sold.
I'll keep the oil extractor in the box.

axis11

No.

The suction and discharge ports does not go straight down. You will have to pass thru the two messing scrolls and when you reach the bottom, oil is not there. Oil is mostly on the back of the compressor near the relief valve area.Its not that difficult to remove the compressor. There is lot of room to move around.

DSMAddicted

Excellent info, thanks.

One more question for you guys. My AC died completely towards the end of last summer.
It used to have issues, but now it's blowing warm, period, hence my decision to re-do everything from scratch, etc.

Simple question: what is the most effective way to test and see if the compressor needs to be replaced? I ask because I vaguely remember hearing super loud belt screeching one of the last times I used the AC last year. It was an especially hectic time for me, so after popping the hood and making sure that all belts were there (especially alternator), I didn't look into it further. Then winter came, and here I am now, with fuzzy memory and just remembering about it.

I am thinking I might have a bad compressor actually (or maybe clutch). Just dawned on me.

Let me know your thoughts guys.
I am ripping everything out and flushing sections, replacing valves, o-rings and all, so any quick suggestion to check AC Compressor before putting it all back together will be helpful.

Thanks!

-Walter

motegicivic

If you remove the compressor might want to replace it. You can check the clutches on compressor with feeler gauge, if you hear noise from the compressor there is a good chance it is bad. If it is original I am betting it is bad, mine lasted almost 13 years. My replacement aftermarket works better than the original honda.

DSMAddicted

Which replacement did you get? New or reman? Brand?

Thank you.

axis11

OP, I assume the a/c system is dismantled now. Have you taken any pressure readings after the problems came up? Readings would be very helpful in diagnosing your compressor and the whole a/c system as well.

DSMAddicted

Actually not yet, I plan on tackling the AC work next weekend.
Sadly, I did try to recharge the system two weeks ago with a friend (before I read all the threads and learned so much) and I suspect I might have introduced some air and/or moisture in the system, because I don't recall purging the center line (typically yellow) after tapping into the R134a can.

Do you think it's still worth taking some pressure readings before evacuating the system and starting to take things apart?

Thank you Axis11.

strategy400

I bought this:

http://www.ebay.com/itm/1994-1995-Ho...sories&vxp=mtr

and a new condenser from radiatorbarn.com

and replaced everything but the expansion valve. I poured about 3 oz. of oil in (system has 4 - 4.5 normally) and so far everything is quiet and smooth and uncomfortably cold inside.

Also, I bought the cheap vacuum pump from harbor freight and vacuumed the system down as far as it would go (is it 29 hg?) for about 45 minutes.

Then, I had also purchased a cheapo digital scale from harbor freight so I could weight in the exact amount of refridgerant (R134a in my case). I weighted in 530 grams, which is near the middle of the spec for my system (1995 del sol). I just weighed a can and placed the can on the scale and sucked it in then weighed the empty can (valve on in both cases) and deduced that the can held ~330 grams. Then I placed the next can on the scale while charging and could actually watch the grams leave the can. When it was down 200 grams I was done. Also, in case this helps - my static pressure was ~67 (car off pressures equlaized between high and low) at ambient 60 degrees outside.

The hardest part of replacing the parts was the receiver drier and it's clamp and the hard lines going between it and the condenser... a real struggle to get them lined up right and working in tight spots, removing parts for access, wiring connectors etc.

Also, be VERY careful tightening and loosening fittings as it is easy to crack bend or otherwise maul the pipes and fittings (the metal is soft and thin). USE 2 WRENCHES and don't over tighten. The o-rings will do their work without 500 lb. ft. of torque. If you crack/strip a fitting/line on a new part you will be heart broken.

Summary: right amount of oil + right amount of refridgerant + be careful + try to do it right = ice cubes spitting out of the dash.
Anything else = hate yourself and want to die.

motegicivic

The compressor I got was from Advance Auto, I ordered it online, it was new and not a remanufactured unit, just slightly more for new. I do not recall the brand, but it had some chemical added called "ice32" which is supposed to make it cooler, works great. Also replaced the dryer.

When adding you can go by ounces there is a service label typically about 22oz going by memory, so say a can is 16 oz use one can and say 1/3 of another can or 12 oz cans use 2 etc slightly less.

You should take pressure readings before you start the work, you need the low and high sides, then cross reference AC charts to give you an idea of what is wrong.

strategy400

I went with grams because metric system has less issues with "weight of liquid oz." (seeing as I was weighing in the refrigerant with a scale) plus just easier to be more precise.

My compressor was new and as long as you source it from a reputable place it should be ok.

Pressures aren't really as much of a concern when you have an evacuated system and you are weighing in the specified amount of refrigerant. I just posted my pressure for reference for anyone wondering what the pressure readings were after weighing in the refrigerant. I can post my high and low/cycle on/off readings if anyone wants.

My car didn't have a service label for the A/C (or it was missing) but I found a Honda A/C installation guide for my car with the specs.

DSMAddicted

Great info. Thanks for sharing your notes man.

Good to know. Would you guys happen to remember price and what kind of warranty on your respective compressors, by chance? I am also thinking about investing in a screen kit like this one when putting everything back together.

Would it be too difficult for you to share that on here? I can host the image/document, if you need me to. Or is it simply a link?

Thanks.

motegicivic

http://shop.advanceautoparts.com/web...___#fragment-1

use promo code p20 to save 20%

If might have the oil already in it, if you order it look at it sometimes they are prefilled.

I got mine close to 3 years ago and can not remember the brand, the link above has 2 options depending on availability.

strategy400

Usually the compressors come with enough oil for the entire system (too much). Each component requires a certain amount of oil.

The links to the install guide were on here somewhere.

I'll attach a zip.

It's really for 1995 only (might apply to 1994).

DSMAddicted

Thanks man.

Excellent, thanks for sharing.

Former User

If you have not already disassembled the A/C system, then I suggest that you place it under deep vacuum for a few hours and then recharge it with the proper weight of R134a. Afterwards, use the manifold gauge set to measure the high and low side pressures with the engine running at 1500 rpm and the A/C running on Max cool. Post the pressures, as well as the outside temp and humidity and the air temp discharged at the center vent. This information will expose any problems and allow you to diagnose them.

DSMAddicted

Thanks Ron.
Problem is, I don't have a recovery machine, so I'd be wasting quite a lot of R134a.
I have brand new dryer, evap assembly, expansion valve ready to go in.
I bought a LOT of tools for not being a shop (good set of manifold gauges, reusable flush kit, two taps, valve kit, vacuum pump and more)... do you still think it's worth to load the system just to get the readings if I was planning on swapping all the above anyways?

Just trying to prioritize steps/options and budget carefully.

Thank you.

Former User

Have you priced the cost of just refrigerant recovery by local shops?

The cost for 2 12-oz cans of R134a would be about $20.

If I understand correctly, your main question now is whether or not the current compressor is bad and should be replaced. This gives you 2 options -- (1) buy a known good replacement compressor and install it along with the other items on your list or (2) vacuum and refill the system with refrigerant and oil so that you can measure high and low side pressures for diagnostic purposes. The latter seems like the wisest choice to me because you really don't know why your A/C failed in the first place.

DSMAddicted

No, I was trying to avoid dealing with shops altogether. I am sick of them.
But I understand I am limiting my options here.

Actually, $30 at walk-in price. They all seem to be $14 per can. I can -however- get them for $9 each through a friend's commercial account.

Probably what I will wind up doing. I will be investing most of this weekend flushing and replacing everything (including evaporator assembly, expansion valve etc) and I don't feel comfortable risking to mess everything up by giving my 19 year old compressor another chance.

Makes perfect sense. A new compressor, however, is the last piece of the puzzle that will practically make my AC system brand new (again, already have evaporator assembly from '99 Civic with cabin filter slot, new expansion valve, new dryer, new o-ring kit, new schrader valves etc).

Given the very limited free time I have, and considering that an extra couple hundred bucks for a new compressor are not going to kill me and might be a wise investment that will save me a lot of time down the line, I think I'll go ahead and go with option #1.

I realize the purpose of this thread evolved into something different through the past days, but things changed as I did more research and weighed my options.

Former User

I can buy 12-oz cans of R134a for $8-9 from my local Walmart.

Are you also replacing the evaporator and condenser?

DSMAddicted

Update: After a whole lot of research on the strangest AC Compressor brands from local stores (Tough One, Murray, Four Seasons <-- bought by Murray afaik, Evercool and many more - all between $250-310 + tax) and seriously considering a $130 eBay one, I finally made my decision and ordered a brand new Denso unit from Amazon. AdvanceAuto sold it for like $310 + tax - $50-60 (coupon), but Amazon at $243 next day shipping seemed like a no brainer.

I also ordered the AirSept suction screen kit from a local AutoZone.

That's a great price. Let me check my local Walmart, good idea.
Yes and no. Evaporator: I am installing the one from a '99 Civic, so I can do the cabin filter retrofit.
Condenser: no.
I am, however, flushing every component separately (lines, evaporator, condenser) using this guy I just got in the mail.

New compressor, new expansion valve, new dryer will be installed after everything else has been flushed and plenty of compressed air has gone through to ensure no residual chemicals are left behind.

If all of the above doesn't give me nice cool A/C (assuming I manage to do everything correctly), I don't know what will.

Former User

Not sure how you decided that among the key A/C components, this^ was the only one that was fine.

DSMAddicted

I figured it's a simple component with no moving parts.
My logic is: if the condenser is physically good (no leaks) and it flushes clean (as much as I can tell), it should be ok.

Please do correct me if I am wrong. I am fairly new to this.

Former User

The evaporator also has no moving parts. Really, only the compressor has moving parts, except for the condenser fan. While the condenser has no moving parts, it like the evaporator is a critical A/C component that relies on very efficient heat exchange. If the condenser metal is corroded or the condenser is clogged internally, or the condenser fins are bent or clogged externally, there will be poor heat exchange and therefore poor cooling by the A/C system.