Re: 1984 4wd SR5 - Air conditioning compressor blown shaft seal

[84sr54wd]

Hey guys,

When I first got my Tercel, 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 were in the 225-250 range on a good hot day at the high end.

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 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

[irowiki]

Have you replaced the expansion valve? That's the most restricted part of the entire system.

Also I'd replace the drier again as it has probably trapped some stuff.

[84sr54wd]

I have not replaced the expansion valve yet....I know i can get it from rock auto and another drier too for pretty cheap. I am concerned with how hard the expansion valve is to get to since my understanding is that it is in the heater box. I can't find any youtube vids of people doing this job on this car. I am wondering just how much of the inside of the cabin has to come apart?

[irowiki]

Oh the expansion valve was easy.

Glove box came off, a few of the vents came out, then the "cooling unit" came out. The FSM details it!

[84sr54wd]

Yeah I've been reading up on the cooling unit removal in the factory service manual. Fortunately I have that. It looks like you just disconnect the two lines under the hood at the firewall and then everything else is under the dash and that center section between the heater core and the blower fan comes out. I figured while I'm in there I'll put a new evaporator core in it as well since I found one on RockAuto for 55 bucks.