If that be the case, then someone needs to inform DHL and Rock Auto as DHL definitely has my order and this is not the first time.

 

Most of the things I order from RA come via DHL. I live just outside of Chicago (near O'Hare - northwest 'burbs) and don't notice a difference between UPS and DHL, with respect to delivery times. But, maybe being near a major metropolitan area helps. With Amazon, if the price is close, I usually go with them. They're much faster.

 

Agreed.

I always shop around, even checking E-Bay; like that old girl says in the song "my momma told me - You Better Shop Around"

In many cases, Amazon Prime comes out the winner;but, in the case of my new A/C compressor, Rock Auto price for the exact same kit was nearly half; and, coming FedEx, it did get here QUICK.

I ordered 8:AM Monday the 22nd and had it in my hands by 1:PM Wednesday the 24th.

However, if Amazon Prime had of been reasonably close in price, even ten or fifteen dollars more, I would have went with them due to their history of FREE and EASY returns and refunds and replacements; I have never yet had to return anything to Rock Auto, but I can't imagine it would be as simple (and FREE) as dealing with Amazon Prime; having to pay for return shipping on something as heavy as that compressor kit would take a big chunk out of the initial investment.

 

OKAY....., back to the A/C questions...

The new compressor came with Black O-rings to go under the two little manifold thingies on top of the compressor.

I have multitudes of Green refrigerant O-rings (are they HNBR ? )

Will I be fine to just use the supplied Black O-rings; or, would it be advisable to use my Green ones instead ?

Thanks.

 

I cant remember what mine where green or black as it has been years since I did this.

I think if I had the right size rings in grfeen I would go with the green ones.
Dave ----

 

In the many years that my switch was bypassed, I never did experience the compressor icing over; it always would freeze your drawers off and the longer it was on the colder it would get.

With the fan on the slowest setting, it would get downright frigid.

I did recently drive a 379 Peterbilt for a couple weeks haul and it was like you describe = cold as Christmas for about fifty miles and then quit cooling; turn the A/C OFF, give it a few minutes for the ice to thaw, and then freeze your tail off again.

On that truck, I believe the blower would actually start touching the ice; at least it sure sounded like it did.


As for the pressure switch, I learned something today.

I was under the assumption that, if I unscrewed the pressure switch, it would be an open hole into the system and should only be messed with when the system was open anyway, hence is why I had a new switch on hand so I could swap it in while the system was down.

I also had this really neat brainstorm about injecting the Dye.

I watched several videos where these guys were trying to pour the Dye from a big old bottle and dribble it into the gauge hose a few drops at a time and they had it dripping off their elbows and all over everything else and hardly any where it needed to be.

I thought, I could beat that.

Being a cow man, I always have plenty of syringes and big/long needles around.

My plan was, when I got the pressure switch removed from the accumulator, I would use a syringe to squirt the Dye in that opening.

Imagine my surprise when I removed the switch and found a valve-core behind it = I could have replaced that switch years ago and lost nary a drop of refrigerant.

The presence of the valve core didn't deter me from my mission though; I removed the core, squirted in my 15cc of Dye, and replaced the core with one of the new ones that came with the compressor kit.

I would probably have been okay using the original 1985 valve core that was in there, but I replaced it anyway.

So, the moral of this story is, if you need to replace the pressure switch, just screw it out and screw the new one in and no gas is lost.

I am going to copy/paste those instructions about how to adjust the switch so I can refer to them out on the trail and all. Thanks.

 

Always be ready with the new switch. Schrader valves tend to leak sometimes, so be ready to quickly screw the new switch in place. That's why the service port caps usually have o-rings in the top of the cap. The service port caps tend to leak also. That is one of those hard to find leaks. You put your equipment on the service ports, no leaks. Take your equipment off after filling, and a couple of weeks later, no cooling. The dye is really handy for those, you can clean the area around the service ports and then a couple weeks later you can see where the dye has leaked out around the service port.

 

Interesting. I suspect your AC system was operating slightly below max efficiency all this time for reasons unknown. Say 80%, just a guess. The system never got quite cold enough to cause ice to accumulate, but still felt plenty chilly. For example, if the coldest output was 42F, you'd never get ice. Even if the low-limit switch was active, it would have never turned off the compressor.

That's why I often suggest keeping a pocket thermometer in the center grill. I have a Taylor 6091N:



Lots of similar thermometers available, all under $10. I like this one because the needle is straight up at 40F, so it's easy to monitor as a glance. The upper end of the range is fairly low, too. No need for a cooking thermometer which may read substantially higher, with reduced resolution in the normal AC range.

I like being able to keep tabs on the AC performance. Realistically, you can't feel the difference between 38 and 45F. The former is good, the latter indicates the system may need a little love. Think of the thermometer as a distant early warning system for the AC.

 

Do not get stuck on certain temperature numbers. The system is designed to drop the ambient temp a certain amount of degrees. If it turns out to be a 25 degree drop, then if you are pulling in 90 degree outside air, your outlet temp will be 65 degrees. Of course on a very hot day you can put the system on max, and re-circulate the cooler air. You probably could have 40 degree outlet air, pulling in 65 degree air from the interior of the vehicle.

I do not know the official system temp drop numbers, 25 degrees is a number I pulled out of the air

 

Those Taylors are good; I have had one in the dash of every truck around here for years.

I saw the "holster" off, leaving just that area where the pocket-clip is; that way, I can clip the sleeve to the vent louver and slide the needle through it and into the air stream.

By the way, mine are old enough to have metal pocket clips instead of molded plastic.

I did go one better than the Taylor milk inspector thermometer in that I had a LCD digital read-out with about a three-foot cord with the sensor on the end of the cord.

I could read those big black numbers on the LCD screen a lot better than trying to see the fine print on the Taylor; alas, something happened to the digital and it quit working.

Last fall before my huge leak, I was seeing vent temperatures of between 26-30° on 80-ish days whenever I put the blower on the lowest speed; High fan would raise it to between 32° and 36°

Kicking on my "Blower Turbo Boost" would make the fan go crazy and the vent temperatures would raise to around 40°

For those curious, I have twin relays on both the Hot and Ground wires of the blower such that I can energize the relays and the blower gets full alternator voltage; I bet it triples in speed.

For the nay-sayers, it has been like that for several years and still going strong; not enough current kills more things than plenty of current ever did.

 

Although I am not finished ----- I think I got it fixed.

I am too worn out to go into all the little details, which I will later.

I pulled vacuum for six hours and let it sit under 25-inches Mercury for another hour and the needle never flinched; that gave me confidence to continue.

51° outside last night.

I started adding refrigerant last night at about midnight = more about that nightmare later.

Anyhow, I bypassed the pressure switch to keep the clutch engaged and added two cans refrigerant; if things were still pouring a leak, I didn't want to lose any more than that.

At the 1-1/2-can point, I had a steady 10 on the Blue gauge and 125 on the Red gauge; the accumulator was a solid chunk of ice and the big line across the firewall was heavily frosted plumb to the compressor.

I had the switch on Max A/C and the blower on normal High.

I hopped in the cab for a look and had an unbelievable 10° at the driver side vent.

I switched the blower to the lowest and watched the needle on the vent thermometer steadily drop to just below ZERO ! = I'll take that !

I know that adding another can will be the end of these super-cold temperatures; but, as it is, the dumb pressure switch won't let the clutch engage with the amount that is in there now --- unless I can dial it in --- or, just leave it bypassed.

I let it sit the rest of the night and had to make a little trip this afternoon and I still have plenty of cool air; I drove about five miles and the dash temperature was at 18° and you could hang meat in the cab.

Try as I might, 20° was as cold as I could ever get it with the old 1985 compressor.

I don't know how much of this improvement is the difference in compressors or how much can be attributed to the fact that rebuilding the compressor bracket has really stopped that flopping V-Belt and maybe stopped some slippage.

I will be able to tell when I hook up a trailer as the trailer vacuum pump is on that same belt; if the trailer vacuum recovers quicker, I will know that belt was slipping a bit.

I wish I had thought to take pictures of that thermometer as I fear it won't drop that low again until that last half-a-can I added leaks away.

Adding that final half-a-can explains the 18° I got today instead of dropping below 10°.; plus, it was 59° outside instead of the 51° of last night.



Forgot to add = adding that final 1/2-can made for a steady 20 on the Blue gauge and 150 on the Red; it held that for a long time.

There are about ten sets of numbers on the face of my gauges and they are not right here in front of me; the numbers I refer to are the biggest easiest to read numbers; I think they say PSIG.

 

Report = Five days since adding the first two cans of refrigerant:

74° outside after a high of 81°

92° on the dairyman's thermometer poked in the dash vent.

Heater Core valve closed.

Twin Condenser fans on.

Engine throttle at 1600-rpm.

Note: I need to measure for accuracy; but, the V-belt drive pulley on the crank-shaft is basically the same diameter as the A/C pulley; so, if my understanding is correct, compressor rpm is equal to engine rpm.

I fired her up and put the A/C on Max and blower-fan on the lowest/slowest setting.

All readings are American - Fahrenheit.

Readings taken at the dash vent just right of the column; the one that blows in my face.

Within minutes, I had 16° at the vent; this on two separate thermometers; my old 1-inch ZERO to 220° and my brand-new 2-inch -40° to 120°; both were reading exactly 16° and held it for ages.

I then shifted to High on the blower and flipped my "Turbo Boost" switch; anything loose picked up and blew to the back of the sleeper, my Walls blanket-lined jacket, two pairs of gloves, a big box of Kleenex, anything that wasn't bolted down.

I watched the temperature climb to 26° and stay there; I checked it several times during an hour and it never flinched.

You could hang meat in the cab.

Some years ago, a long-time refrigeration technician, who has spent his life servicing dairy milk coolers, and servicing trucks and farm tractors in between milk cooler crisis, explained to me that R134a cooled best at what most would consider much too low low-side pressures and recommended that the low pressure cutout switch be tuned to accommodate these low pressures; I believe he was onto something.

 

If you suddenly hear the belt squealing, quickly turn the A/C off. If you get the evap coil too cold, not all the refrigerant will turn to a gas. If liquid refrigerant hits the compressor it will lock it up. Getting super cold is not a good thing sometimes. That is why a freezer has different refrigerant. Different refrigerants turn into liquid and then a gas at different temps. R134a is not suited for a freezer for this reason.

 

Just bought this- thanks.
Not looking to hijack but a quick question:
I need all new components in my '85 Bronco AC setup.
Should I just buy all new original style components and a conversion kit to fill it
or is there an easy retrofit that doesn't include swapping over to serp belts for the 134a (fs10??) compressor?

Is the conversion kit just adapter fittings for the service ports?

Is there a particular original 1985 AC components "conversion kit" that works the best?
Oops, that is three questions.

 

You can buy just the conversion fittings, but a proper conversion "kit" gives you the r134a with the ester oil already in the refrigerant. If you want to just drop in the r134a you have to put a vacuum on the system for a couple of hours, then you have to add the r134a WITH the ester oil. The other oil type that is used with r134a is PAG oil. If you use PAG oil, everything needs to be flushed or new. The old R12 oil cannot be left in the system if PAG oil is used for the conversion. R12 oil can be left in the system if you use ester oil.