Revitalizing my AC system

[95C1500]

My truck has been without AC for a year now... This Texas summer will probably put an end to that

 

[kennythewelder]

I will never again have a car or truck without AC. It is just way to hot in south Louisiana to not have AC. It's already in the mid 90s.

 

[PeteyG708]

Seconding the “A/C in Texas” thing. El Paso is getting hotter and hotter, and it sometimes seems that the AC doesnt work!

Anyways, yes, charge the system with the dye added to the freon and use it. After some use, the leak should be covered in the dye, so you can use a UV flashlight to find the leak. Evac the system, repair the leak, replace what you want, and charge it up. Badaboom... solved.

On mine, it worked when I got the truck. After a while, it stopped blowing cold. I added a can or two of the black 134a (forgot the name) at that time. This was back in th 190Ks, and she has 220 now (bought with 186K). A/C works perfectly today, and all I did was add freon.

 

[Ken K]

Thumbs up on the nitrogen test as this is best practices. We used a tank at the dealer. I have more tools and equipment than a man is allowed to own, but I have a small tank of nitrogen, 2 sets of gauges, regulator, tank of R134a, GM O-ring kit, in-line-filters (ACDelco), J-Tool line repair kit, PAG oil injector kit, 2 vacuum pumps and a refrigerant identifier (At home / Retired). Yea crazy, but I have a diff spreader also.
With a heavily regulated industry, shops with charge stations are equipped with identifier and the stuff sold in the aftermarket, cans of "Fix-It" juice contains nasty solvents designed to swell O-rings and seals, plus they contain ester oil. Ester oil will turn to acid when exposed to moisture if a leak occurs in the future. Some solvents will dissolve the desiccant bag in the accumulator. This juice will be flagged as contaminated every time if you go in for service at a licensed shop for future A/C repair. They have 3 tanks for cleaned, new or other (Contaminated). They have to pay to get rid of it. The can stuff will cause trouble.
The contaminated stuff will damage your HVAC and a shops equipment, thus a filter & identifier are mandatory. Use nitrogen and HVAC soap, fix what you have, vacuum leak check, replace lost PAG oil volume, install a good quality dye, then charge the system. Maybe I am too picky, but 30+ years of doing repairs from bumper to bumper, cutting corners will bite you every time.

 

[Coveman]

The o-ring in the charging valve goes bad and the shrader leaks by. Very common on our gmt400s. Mine blew the plastic cap off the Schrader valve.

Get a replacement valve o-ring, a 20 dollar 134a recharging kit (get 2 or 3 cans of 134a so you have them handy) and follow the directions. Mine still had some charge in it so I didnt evacuate the system and it has been ice cold ever since.

 

[NightRunner]

I used to run mail in my old S10 Blazer with no AC. I was drenched in sweat almost 24/7. Now I'm faced with this truck and it needs an A/C overhaul. Previous owner self tapped the transmission cooler to the condenser so I know it needs to be replaced along with the two O-Rings that it goes into, but I don't know the condition of everything else. It'll probably just be a "replace the known faulty parts and see what happens" type of thing

 

[df2x4]

Previous owner self tapped the transmission cooler to the condenser

Wow...

A set of mounting ties is like $2, that's ridiculous.

 

[NightRunner]

Wow...

A set of mounting ties is like $2, that's ridiculous.

Exactly my thoughts. The only reason I think he would do that to the condenser is if the A/C system wasn't functioning when he did it. So if that's the case the condenser might not be the only thing that's bad in the system.

 

[Geo's66]

good information- another question. my 96 which is now out of college kid duty and with me is weak in the AC department. blows cool, not cold. 1st thing to do would be what? thanks guys. also, the blower fan for heat or cold is squeeking. that needs to be fixed as well.