All of these questions pertain specifically to the factory A/C on my 1985 F-350 Ford.


1. If I replace the "discharge" hose, the one between compressor and condensor, assuming that the 134a has all leaked out, must I pull a vacuum on the system, or can I simply re-charge ??

2. Must I also replace the drier/accumulator ??


3. Although freely leaking at the crimp on the discharge hose, the thermometer in the vent still shows 40* on Max A/C in 85-90* heat; why does almost every hose, the accumulator, and the entire top of the compressor, have condensation pouring off of them ??........Maybe this is normal, but I had never noticed it before.


Thanks.

 

[/QUOTE]You need to vacuum the system. This is due to water vapor that is in the system. Dont forget to add a bit of oil too.

I would. If it has leaked for a while then your going to have it open to the atmosphere for a while longer its a good idea. It absorbs moisture really quickly.

Sounds like you still have a bit of refridgerant in the system. I would recommend taking it to the local shop have them draw it down. Take it home do the work on it. Take it back to the shop and have them vacuum it and recharge it.

Its normal because they are cold. When something is cold moisture condenses on it, like ice tea summer.

Your welcome.

 

In a normal sealed A/C system, there is a certain amount of compressor-oil and the rest is refrigerant.

When a hose starts seeping, as mine is, is it only losing refrigerant; or, is it also losing oil as well ??


When adding a can, to keep up with the leak, should plain old R134a be added, or should the deluxe kind that has oil added be used ??


Also, what about the various kinds I see that have "leak stopper"; do they work or are they just snake-oil ??

Thanks.

 

Yup. Differs from system to system. The oil is lubricant for the compressor. It also flows through the rest of the system and coats everything. When you replace parts your supposed to replace the oil as well.

Both. The oil is atomized and traveling with the refrigerant. Its also how we techs find the leaks. Usually there is die in the oil to help with that.

I am honestly leery of the add a can stuff. How do they know how much oil for each system they inject? You should be ok adding with out since your going to change the parts soon. But when you draw down and open the system add a few ounces when you recharge.

Oh no, they work. Stop the leaks cold. Or should I say hot. Because thats what you eventually feel out of the ac and then its time to change the entire system. Fun fun fun. Its like stop leak in the coolant. What happens is it eventually becomes nice and solid and blocks passages. Or, even better, gets into the compressor and gums it up. Stay away like the plague!

 

Thank you very much, Mr. tmleadr03; I feel some smarter, already.

 

Smarter I cant fix, knowledge I can help with.

 

I agree with teamleadr03, except I'd replace the dryer just because it's an 85' model, but still again if it still has freon in it and still working....hmmmm, probably not. Worked on Cadillacs and only change the dryer/Accumulator if

A) the dessicant bag broke open
B) severe metal failure, i.e compressor internal failure and that means orifice blocked completely with metal. Minor failure it got a compressor and GM filter.

This is how we did it, how the man that trained me has been doing it for the last 25-30 years at the same Cadillac dealer. Problems, none.

I'd also stay away from the "leak fix" freon, it blocks small orifices correct? What is your evaporator full of??? This is the same question GM brought up and said they have found it can seal up your evap and if there is one part of the a/c you don't want to have to replace it's that. Usually burried behind dash in most cases.

As far as oil and dye mixed freon I'd say go for it. You don't know how much oil has leaked out over time, again, the a/c sounds like it's still working. The can will tell you how much of an oil charge there is, I believe it's 2 oz's. If your system requires 3 cans to charge I'd throw two in with the oil charge and put in a total of 4 oz'z of oil and let it ride and that is what I would do to my own and not be worried. There are exact figures for each component, condensor requires this, compressor this and so on. But when it comes to aged vehicles and things sometimes you just have to make an educated guess.

Tmleadr03's advice is top notch and correct but there is flexibility in the lingo and how it can be done and what will work and work properly. Most folks don't have the money to replace every component that is suggested to replace when things happen. When they first came out with R134A and you wanted to convert a R12 system they said you had to replace all seals with new ones, do this do that. When I left the auto world to convert you evac'd the system, checked for leaks, put in a certain amount of new oil for R134A and recharge to a recalculated amount and you were done.

I would take his advice on the take it to some place and have them evac the system cause it is a $10,000 fine for releasing refrigerant into the atmosphere....at least that's what I remember. If you don't have a vacuum pump, same thing, you need to vacuum the system, let it sit and make sure it has no other leaks, also a violation, knowingly recharging a system with a leak.

 

These guy's deffinetly have you going the right direction. I change the receiver drier on my trucks whenever I have the system open, it is essentially a filter and at 40 bucks it is cheap insurance, I also always bring the system into a vacuum for a minimum of 30 minutes, it takes care of the moisture and helps to determine the sealed condition of the entire system, then a shot of dye/oil and 2.5-4 #'s of refrigerant depending on the truck I am working on.


Tim

 

A little more history on the 1985 system :

Around fifteen years ago, I had the local expert to fix a major leak, give the whole system whatever he deemed necessary, and convert it to R134a.


What sort of amuses me is the way the government made the big scare about how dangerous Freon was, and how it would bring about the end of time, should more than a few drops escape into the elements; but now, since hardly no one still uses Freon, they make a worse deal over the supposedly safe R134a.




I have another question :


Seeing as how my compressor is 23-yrs old, I was wondering if it would be advantageous to baby my leaking hose until summer's heat is over, then evacuate the system, and replace the bearing(s) in the compressor; or, would it be smarter to simply let it go until it locked up ??


I have an identical compressor, with hardly any miles on it, that I robbed off of an old Bronco we used to have, but the belt-pulley on it is for the little skinny belts, "A" I think; whereas, the belt-pulley on my truck is the much fatter "B".


Thanks for all of your help and information.

 

I have always been a fan of letting it go till it dies on my own cars but love to replace good parts customers tell me they need. If it aint broke dont fix it, unless someone wants to pay you to do so.