Getting Neglected A/C going

[BlueCruiser84]

Hi all,

The AC is my 94fzj80 has not worked since I bought it 8 years ago. It had no charge in it and I didn’t really care. I disconnected it once to get to the heater core ~6yrs ago and about a year ago removed the drier for a high clearance bumper And just left the lines dangling open. I never intended to have AC. Well, now we’d like to go on some longer highway trips and listening to mud tires and wind with a wife and two kids ain’t cutting it.

I’ve relocated the drier to the battery box with the r12 lines and now I’m wondering what else I need to replace/inspect before trying to charge the system. I’ve not messed with AC before because it’s not my thing, but now I’ve got a vacuum pump and a set of manifold gauges and I’m ready to dig in.

I bought a new drier and new orings and those came with an expansion valve - all will be replaced. Anything else to check? I’ll blow out the lines when I replace the orings. I need to figure out if my compressor is any good, but then what? Pull vacuum and if it holds then charge it up?

 

[ppc]

There is a good possibility that an AC compressor that hasn't run in 8 years is trashed and going to need replacement.

 

[flintknapper]

There is a good possibility that an AC compressor that hasn't run in 8 years is trashed and going to need replacement.

^^^^
Yep.
The entire system has basically been open to atmosphere for the last 8 years. Compressor is a definite No-Go. And if it were me....I'd flush the hard lines and replace everything else (Compressor,Evaporator, Condenser, TXV and Drier). I'd disconnect each and every fitting, install new O-rings with Nylog.

 

[BILT4ME]

^^^I agree^^^

 

[BlueCruiser84]

What trashes the compressor? It just corrodes inside and will be locked up? Or something else?

As you can tell I know zero about HVAC.

 

[BILT4ME]

What trashes the compressor? It just corrodes inside and will be locked up? Or something else?

As you can tell I know zero about HVAC.

The moisture from being exposed will rust the pistons and seize it or make it so it won't seal.

Not worth even trying to recover it, really. The oil in it would have also taken on moisture and turned acidic.

The dryer has a desiccant in it that must be replaced. If the system would have remained sealed, then it may have been recoverable, but with the lines open, no.

 

[1972FJ55]

I'd suggest removing the compressor, since you'll need to drain the oil out anyway, remove the 4-bolt cover where the hoses attach and visually inspect the two ports. Then see if the front hub will turn by hand. If it does, it may be salvageable, but realistically, if this is a keeper vehicle, just replace everything and call it good.

 

[BlueCruiser84]

I'd suggest removing the compressor, since you'll need to drain the oil out anyway, remove the 4-bolt cover where the hoses attach and visually inspect the two ports. Then see if the front hub will turn by hand. If it does, it may be salvageable, but realistically, if this is a keeper vehicle, just replace everything and call it good.

it’s a keeper, but it also looks like a raisin. I’ll do some investigation before I go replacing things. Sounds like compressor is probably toast though.

 

[dugsgms]

I would add that if the lines were left open for a length of time I would flush rather than just blow out the lines. There are products designed just for this purpose, some are just a evaporating solvent and some are a degreaser mixed in a a/c safe oil, I prefer the former but have used both with good results.

 

[BlueCruiser84]

The oring kit that RockAuto sent is wrong. Guessing they are SAE instead of Metric. I’ve got a bunch of metric orings and the sizes match up, however, does the AC system use a special material? The ones sent by RockAuto are green and the ones I have are black - that’s the extent of my knowledge.

I could go to the dealer, but my dealer rarely has what I need and it’s Sunday.

 

[BlueCruiser84]

Ok. Here is a picture. Oring off hardline that runs into the condenser. Green orings are from the kit. Black is factory ‘94 cruiser. Neither of the green options look right, but this is the kit that comes up in my internet parts searches. I’ve ordered the Santech kit which I should have in the morning, but online it looks exactly the same as the gpd kit I have currently. What am I missing here...? IDs match on smaller one but ODs are way off. ODs are close on larger one but ID is way off.

 

[flintknapper]

The oring kit that RockAuto sent is wrong. Guessing they are SAE instead of Metric. I’ve got a bunch of metric orings and the sizes match up, however, does the AC system use a special material? The ones sent by RockAuto are green and the ones I have are black - that’s the extent of my knowledge.

I could go to the dealer, but my dealer rarely has what I need and it’s Sunday.

They can be either color you want (HNBR) O-Rings for A/C applications. HNBR o-rings are made from hydrogenated nitrile

 

[BlueCruiser84]

So any thoughts on those orings? I don’t know how much size matters here. If it fits - it works? Or if the rubber portion is too skinny it won’t seal. I don’t have my vac pump yet so I can’t test anything.

 

[JeepinPete]

I strongly recommend getting the o-rings from Toyota. I went through this a couple years ago. Replaced every o-ring with a kit from Rockauto. In a years time, two of the new o-rings leaked. It is beyond frustrating to go through all of the effort then have something as insignificant as an o-ring take you back to square one.

 

[BlueCruiser84]

Just an update and a PSA. Do NOt use the gpd kit that comes with gpd products. The orings are the wrong size. I picked up a Sandtech kit from autozone and the Orings are the correct metric sizing. I’m going to replace them all and pump the system down and see where I’m at.

@JeepinPete I went to the dealer and they said if they need a kit they just buy it from the local auto parts place rather than piece everything together. Seems silly Toyota doesn’t have an oring kit for similar vintages. I’d imagine most vehicles across their lines use the same Sizes? I didn’t have the patience to sit their with the parts guy and pick out every oring.

 

[ZackR]

FWIW I rolled the dice and my compressor worked just fine. Similar to the OP my system was open for 5+ years before I decided to bring it back online.

Repairing the AC is definitely in the top 3 best decisions I've made for the cruiser. Driving home yesterday in 90F+ weather, stayed nice and cool. The AC system on these once fully functional is enough to freeze you out.

 

[BlueCruiser84]

FWIW I rolled the dice and my compressor worked just fine. Similar to the OP my system was open for 5+ years before I decided to bring it back online.

Repairing the AC is definitely in the top 3 best decisions I've made for the cruiser. Driving home yesterday in 90F+ weather, stayed nice and cool. The AC system on these once fully functional is enough to freeze you out.

I turned the compressor by hand and it felt tight but smooth. Being totally ignorant as to what a compressor should feel like I’m going to take this as a good sign!

 

[flintknapper]

I turned the compressor by hand and it felt tight but smooth. Being totally ignorant as to what a compressor should feel like I’m going to take this as a good sign!

Exactly what it should feel like. But personally, I'd be leery of using one that had inoperable and open to atmosphere that long.

But...your luck might be better than mine.

 

[BlueCruiser84]

Here’s another n00b question. How do you determine how much oil to add to the system? Is flushed the condenser and it was just nice clear solvent that came out. May have been some oil in there but tough to tell. I didn’t remove/replace anything else except the drier.

I put vacuum on the system and left it overnight - no change. That’s a good sign at least.

When you vacuum the system does that remove oil? For example everything I read says turn the vacuum pump on for 1+ hrs to fully vacuum the system and remove all moisture. Is the system empty at that point or does the oil stay in?

 

[flintknapper]

Here’s another n00b question. How do you determine how much oil to add to the system? Is flushed the condenser and it was just nice clear solvent that came out. May have been some oil in there but tough to tell. I didn’t remove/replace anything else except the drier.

I put vacuum on the system and left it overnight - no change. That’s a good sign at least.

When you vacuum the system does that remove oil? For example everything I read says turn the vacuum pump on for 1+ hrs to fully vacuum the system and remove all moisture. Is the system empty at that point or does the oil stay in?

Oil is not removed during the vacuuming process. It is mostly suspended in the refrigerant and 'most' is lost when a system is 'evacuated' BUT in the case of leak (especially a slow leak) some amount of residual oil will pool in the lines, condenser, evaporator and drier. How much...is anyone's guess. That it is why it is best to flush a system that has been sitting for awhile or the condition of which is unknown.

Most systems (empty) will require 7-8 ozs (total system including the compressor). Too much oil will result in poor A/C performance, too little (significant amount) will result in decreased compressor life.