Automotive Air Conditioning Information Forum (Archives)

cmeseadoin on Sat August 29, 2015 10:40 PM

Year: 1984
Make: Toyota
Model: Tercel
Engine Size: 1.5L
Refrigerant Type: R134-a
Ambient Temp: 80
Pressure Low: 10
Pressure High: 225
Country of Origin: United States

Hey guys,

I have an '84 Tercel 4wd SR-5 wagon and when I first got it, someone had converted the A/C to 134 and it was not working, with no refrigerant in the system. I decided to charge it and see what it would do on the original '84 nippondenso compressor. It charged and worked for a while but I could tell the compressor was weak and one day while driving it, it started making a lot of noise so I shut it down. I determined that the compressor had failed and when I took it apart, there was debris in the oil. I took out the old compressor, bought a new one and then blew everything out as best I could. Evap and condenser especially and replaced the drier. I put in a new compressor, added new oil and did everything correctly, recharged and it ran great and ice cold. After a couple of trips with the car about 150 miles or so, I started blowing oil from the front shaft seal. Pressures at 2K rpm or so were in the 225-275 range on a good hot 90 some degree day at the high end and 20-30 on low side.

I tried to determine if this was just bad luck with a bad seal on a new compressor or if there might be a pressure issue causing the seal to blow. Maybe there was debris still in there somewhere from the old compressor failing and it was causing excessive restriction even though the system was cooling well. I ran into a bunch of opinions ranging from the a/c compressor manufacture I bought the new one from telling me anything over 150 on the high side was way too high to someone telling me that the shaft seal is on the low side of the system so it would never blow due to high presssure on the high side. I ordered a new shaft seal and compressor re-seal kit and tore it down, and put in a new seal. I've been fine for 3-3.5 months now. Tonight I see I'm starting to blow oil again from the shaft seal. I have dye in it and black light it regularly to check it. I'm blowing ice cold air and I'm cycling. Tonight at about 80 deg ambient I noticed about 225 high side but at 2500rpm, about 10psi on low side. In my opinion I might have restriction? Two shaft seals blowing? Any ideas from folks that know a/c?

I'm thinking tear everything down again, blow all lines out again, and maybe replace the condenser this time? Should I replace the evap too? Where can I get these things? I've been looking online. Think I could somehow blow these things out much better than I did before? I just know they are originals and the passages through them are very small. What are the odds I have a restriction with this reoccuring problem and could I save my condenser and evap from having to be replaced?

I took the old compressor apart to see how bad it was destructed and one of the baffle thin metal plates in it was eaten up badly and several of the circular tabs were missing. That means they are in my system somewhere. The pistons were chewed up and there were pieces missing. I'm guessing there is some of that still in likely the two coils. When I replaced the shaft seal on the new compressor, there is NO evidence of the new compressor chewing any metal traveling in the system....so if something is in there, I believe it is fixed in position and not traveling. Any ideas guys?

Chris

cmeseadoin on Sun August 30, 2015 9:39 AM

Does anyone know if, on a 1984 tercel, the expansion valve in with the evaporator in the heater box, contains a screen in it that could be clogged with debris?

cmeseadoin on Sun August 30, 2015 12:40 PM

26 reads and no replies...where are the usual suspects in the know?

HECAT on Sun August 30, 2015 11:02 PM

Blowing thru A/C components does not remove waste oil and debris. Sure you may see a little, and this can be used as evidence of the oil condition and if metal debris is present. If so, a chemical power flush, complete solvent removal, and drying is required. Back blow the condenser into a clean towel. If you cannot make it "like new" clean and dry inside (blowing is not going to do it), it should be replaced. Some of the particulates from the first failure could be restricting flow, and some of the very small fines could be wearing out the shaft seal. But this is all speculation based upon the unknown. The unknown needs to be eliminated.

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HECAT: www.hecatinc.com You support the Forum when you consider www.ackits.com for your a/c parts.

FLUSHING TECHNICAL PAPER vs2.pdf 

cmeseadoin on Wed September 02, 2015 9:29 AM

Thank you for the reply HECAT!

I have taken the system all apart. I pulled the cooling unit from the car and dismantled it to replace the TXV which is inside of the interior cooling unit mounted on the inside of the firewall. The evap did not look bad, and to I chose to blow it out with brake clean and compressed air. I had no problem doing so. I looked at the new evap I purchased from rockauto, but was not really happy with it. It was slightly smaller and the line fitting were not quite pointing the right directions. They could have been bent but I was told if the original can be used, use it. I've had enough experience with various things to also know that you can never duplicate original quality from back in the day. I cleaned it and washed the exterior and blew it all out inside and it seems to be ok. I did the same with the condenser b/c i've not been able to find a new one.

I realize that brake cleaner and compressed air is not a "proper" flush. I am a DIY mechanic with many years of experience across the board with various things. I have gotten into a/c in the last 10-12 years and had excellent luck. How would you recommend that a DIY guy like me flush components like a condenser/evap? I ran a couple cans of brake clean through each until it was perfectly clear and no oil residual. Also, I looked at the oil before I flushed it, which was fluorescent because I have dye in it, and shined several lights on it and can see NO signs of metal fleck or particulate contamination as if there were no particles traveling the system. I spot checked the oil at every line fitting I disconnected.

I'm hoping that either my TXV was partially restricted or failing on operation causing my suction pressures to be as low as 10 and my high side approaching 300 on a hot day.

mk378 on Wed September 02, 2015 9:47 AM

You really should replace the condenser. The serpentine condenser is easily clogged with debris and difficult to clean out. On the other hand, if you have a tube and fin condenser, don't expect good performance with 134a.

HECAT on Fri September 04, 2015 12:09 PM

Quote
Originally posted by: cmeseadoin


I realize that brake cleaner and compressed air is not a "proper" flush. I am a DIY mechanic with many years of experience across the board with various things. I have gotten into a/c in the last 10-12 years and had excellent luck. How would you recommend that a DIY guy like me flush components like a condenser/evap?

The chemistry of brake cleaner is the issue. What is in it (many formulas)? Is it chlorinated or not? What will it do to seals and hoses? Will it corrode metals? Will residues react with the new oils? Will residues react with the refrigerant? I know it is a great cleaner for brakes, but I believe we are messing with too many unknowns to use it for A/C flushing. Chemicals are often produced by mixing a few knows and then applying heat and pressure to make something new. Many do not realize that a very small amount of a unknown chemical added to the oil and refrigerant in a vapor compression system (in operation) can produce some crazy chemical reactions and results. Old refrigerant conversion done wrong even produced copper plating.

I am a mechanical engineer and a self proclaimed DIY at almost everything mechanical. But I often get in over my head, do not have the knowledge, do not have the skills, do not have the tools, and make lots of expensive learning mistakes. So my opinion regarding DIY A/C flushing is to learn the proper way and tool up; or you may just be setting yourself up for a expensive learning mistake. You may pick up some more A/C flushing insight from reading the PDF in my signature.

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HECAT: www.hecatinc.com You support the Forum when you consider www.ackits.com for your a/c parts.

FLUSHING TECHNICAL PAPER vs2.pdf