1988 F350 460

The A/C worked years ago for IDK how long, but it doesn't work now. I was thinking the best bet would be to replace all the O rings and then check the system for leaks.

Are the compressors known for leaks when they sit for ~15 years? Does anyone make a kit to reseal those compressors?

Are there known issues with the A/C system?

Doesn't the dryer wear out or get clogged up over time?

 

How are you going to check for leaks after you remove the refrigerant to replace the o-rings? That would require you to recover any refrigerant, replace o-rings, vacuum and refill the system with some dye. Is there any refrigerant in the system? Have you put gauges on it to see what is happening?

You can usually spot where there is a leak because the oil also leaks out with the refrigerant. Dust/dirt will stick to the oil at that spot.

Does it look like the compressor is leaking?

No. The dryer does not wear out. It is a closed/sealed system.

 

But the dryer does collect moisture from the system, so it can be saturated, right?

I'm going to have a close look at every part to see if I can spot a leak.

 

If you let the system sit open to the atmosphere the accumulator / receiver dryer can / will get contaminated with moisture
When you evacuate and recharge a system the vacuum time is what removes moisture from the system
They used to tell us to evacuate them for 4 hours on the old R12 systems (big) systems that held 3 pounds or more of freon
There is no reseal kit that I am aware of
Yes the comperessor shaft seals do not last forever
Rgink replace not reseal for the compressor
Reseal = replace all the o rings you can get to.
That means re3seal both soides of the condenser and the high side line into the evaporator where the orifice is
Inspect that fixed orifice while you have it apart
I assume you have retrofitted it to R134a already?

 

You asked if it wears out, so no, not if the system is sealed. On the other hand, your system has a leak so while I was replacing the o-rings and maybe the compressor, now is the time to replace the accumulator /dryer.

Who are”they?” I used to be a/c certified a long time ago and have never heard of evacuating a system for four hours! Once the refrigerant is recovered why would you continue to let the machine run for several more hours?

The orifice tube a cheap. If you are going to pull it out to inspect it why would you not install a new one?

I would not assume that. Maybe that is why the system is not currently functioning.

 

Yes, the dryer can get saturated and it is recommended to replace it anytime the compressor is replaced, or the system is open for an extended period.
Nobody ever does
However, most of them are cheap
Back in the day when you could get a decent warranty on a new compressor
They would only warranty the compressor if you had replaced the receiver dryer at the same time
Well, unless the orifice has debris in it, there is no need for a new one. Just lube it with AC oil and push it back in there
They is Ford AC school for me. I got my Ford masters cert masters in 1998
You let the vacuum pump evacuate one for hours on end to remove moisture is the reason

 

MT2526, A/C O-Ring Kit is what my supplier says you need. Probably a generic kit, but it sure has a lot of them.

 

I picked up a generic A/C o-ring kit years ago. It has dozens of sizes in it for a few dollars. Over the years I used most of them when rebuilding a few project cars A/C systems.

As far as vacuuming down the system goes I have always pulled a vacuum for at least an hour or so when I knew the system had been open to atmosphere for any length of time. Also replaced the receiver/drier (accumulator) too. Learned from a few old school service techs in my younger days (70s/80s). Did it help or prevent any issues? Cannot say it did or not. Never had a failure when using that technique.

 

Schrader valves are one of the most common leak points I service.

 

I replaced the Schrader cores per your request, whether they are leaking or not, totally worth it.

 

If the system is empty the dryer is trash now too. Pull the FOT and inspect for Teflon shards. If so, you need a system overhaul.

At this age should have had two systems if truck was used for daily use.

Search on my recommendations for overhaul. It is easy and condenser is THE KEY.

 

+1 for pulling a vacuum for 'some amount of time' if moisture contamination is suspected.
Under a vacuum, the moisture will slowly gasify, and be drawn out.
4 hours seems like a very long time, though- the guys in the shop next to us usually ran it
for half an hour or so. Or however long lunch was, so on Fridays, maybe an hour,
and said the filter/drier could have what was left, if any.

t