Hi guys,

My A/C doesn't work in my truck (94 350 with a 7.5) and due to the age I'm guessing there's massive leaks throughout the system. Anybody have any advice on upgrading/replacing the system and the costs associated? I'm pretty handy with most of my truck related things (righty loosey, lefty tighty and all that) but with the chemicals involved and potential for poisoning myself and the environment I'd like to know how a home wrencher would tackle this kind of thing. For example, replacing the unit I can probably do myself because it's a few bolts, however I'm not sure what's involved with replacing piping (pretty sure it's solid pipe and I don't think they sell kits) and I think that's out of my wheel house.

So, should I just find a reputable mechanic to handle this? Is it able to be piecemealed to save me some money? Should I just give up on it due to the potential cost?

This is my dream truck and right now my DD, I'd really like it to be comfortable for next summer for cruising and general driving so any advice is appreciated!

Thanks

 

no need to replace the hard lines unless they are bad.
you can replace the bad parts, then take it to a pro to evacuate the system and charge it to save some cash.

 

Big list, here we go! Replace all the hoses with modern 'barrier' style hoses rated for R134a/R1234YF, you can get good Gates/Murray brand from O'Reilly Auto (if they are in your state), I would have your condenser and evaporator flushed and leak checked, but if original they may need replacement from buildup/rust. New receiver drier, those capture moisture and should be replaced if the system is open to air for extended periods of time or age. New orifice tube, those keep pressure on high side and drop pressure to low side, they also have a filter screen to pick up contaminants. Go with a red/blue one, most people recommend the blue one. Compressor may need replaced too, there may be Motorcraft compressors still available, I've run a Murray on my truck for 3+ years no issues. There will be several 'green' rubber o'rings at various points on the lines and threaded connections, replace ALL the o-rings even if they look OK. All told you can probably get everything you need from the parts store and it works alright. As far as flushing, let a shop with a dedicated flushing machine do it. When the system is all fixed up also let the shop do a vacuum leak check, this makes sure all the seals are tight and that no refrigerant will be lost to the atmosphere. Its not gonna be cheap, several hundred, maybe north of a thousand in parts plus what you pay a shop. Worth it though.

 

I need to talk to the former owner but I think I'm looking at a full replace/upgrade and even for my own peace of mind I may do it. Especially since I'm pretty sure the old system ran on the old style refrigerant (forget the number associated with that) and not r134a.

I'll start pricing things out and see where I land as far as effort/cost and parts availability.

Would there be any benefit to upgrading anything on this system as far as compressors/condensors? Not just for added reliability but also for how cold the beast can get.

This is a whole new world to me!

 

The most common area of leaks is at the quick connect where the orifice tube is. Your truck already has barrier ac hoses being that it was a R134a system from the start. I also suggest looking at the condenser and replacing it along with the accumulator when doing a ac job. The condenser is prone to deterioration from road debris and it's also available very cheap.

 

FYI- amazon carries "new" Motorcraft AC compressors typically around $250-$300..... just overhauled the wife's 97 Cougar Sport AC systems last year (IIRR)...did it myself...had to use 4-seasons ac dryer/accumulator, etc..... by the time I was done, I spent about $800 for all components including new hoses & Freon.

 

Are the Motorcraft compressors that much better? Or is it because they are a known manufacturer?

 

Depends on who you ask but regardless they ARE the OE part, everything else is an imitation or reproduction, haven't heard of anything supposedly BETTER than Motorcraft for A/C but we have to go with what is still available or still in production.

 

The Motorcraft units are the same as the four seasons. These old Nippondenso units are not made anymore and all the patents have long expired. The last two Motorcraft units I purchased had the Same casting mark as the four seasons and where all made in China. You will notice Ford supports a lot of discontinued products through Motorcraft and Omnicraft with sourced components to fulfill jobber requirements. You are also required to replace hoses and condenser on vehicles built before 95 and subsequently need to have proof or the motorcraft warranty isn't valid.

 

I have never had a issue with AC Delco or MC components...4-seasons, dorman, etc......well, I will say this about 4-seasons.....they are a nationwide mfg......I went through 2 of their AC compressors in 3 years.....the 1st one the compressor housing split down the middle..... the installer (wasn't me...i was busy at work, trusted mechanic) called the wholesaler...they sold the new compressor at costs....(outside of warranty) and claimed 4-Seasons would not back them up. Ok...... now fast forward to last year.....the 4_seasons unit, now 3 years old, internals failed....went with MC......but I had to go with 4-Seasons accumulator.....there was a minor fitment issue....when heated, the aluminum component swelled just slightly making connecting the recharge hose impossible....tried a second replacement...same thing....ending up gently warming the aluminum fitting/assembly and bending the fitting about 1/16"......I called and spoke to tech support...….I was nice but explained the distain I had for their QA issues.....going back to the AC compressors...…. I must say the engineer was very nice....and when he checked the records he found where they were never contacted by the wholesaler......he stated that if he had known, they would have replaced the compressors free even if they were outside warranty...because they wanted the units back to see what went wrong..... very upstanding gent. I must also say, that while this is not unusual for 4-season components, many have had very good durability with the products.

t the time I did my wifes Cougar, the MC units were $100 cheaper than 4-Seasons (amazon), came with a much longer warranty and you could even buy an extended warranty.....(which I didn't do).

 

How does it not work? Does the system not have enough charge? Is there an electrical problem? Your putting the cart before the horse by assuming you need to replace a whole bunch of parts until you determine what is wrong. If it did leak out over time and is just low can you see where it is leaking? Is there oily dirt around the seals or the front of the compressor? You or a shop can put some dye in the system and charge it to find the leak if there isn’t already dye in it. I have used Spectra and Four Seasons parts with no issues at all.

The ‘94 Bronco I used to have was a R-134a system.

 

It might be part number specific....the unit I got for my wifes car was made in USA...……….

 

I'm not sure how it doesn't work, but I was under the assumption it was the old r12 system and not r134 so I thought I would have to replace near everything anyways.

Now that I know more I'm going to take it to a reputable mechanic and have them look for obvious leaks/broken items and then fill it back up and see what happens.