How much R134 do I need for my '85 F250

[stumiister]

The underhood label is missing.
I have the bosses RobinAir a/c recycler/recharger machine hooked up to the truck after everything is out and I have a good vacuum in the system when I go to recharge it how much R134 do I add?

 

[chris142]

I don't have my ac spec book handy. My 87 is 3.25lbs of r12. That equals 2.75 lbs of r134a. You can always go by pressures. Hold it at 1800 rpm amd aim for 2.2 times ambient on the high side

 

[stumiister]

I cant connect the high side I dont have the adapter fitting for it.
I will try that, but if anyone else has any ideas let me know please

 

[Hydro-idi]

I just went to Walmart and kept buying the cans of r134a until the gauge said it was full. Don't think my a/c system was ever switched over to use r134a but it is working fine. Walmart also has the adapter kit. Sounds like you are doing it the proper way which is even better.

 

[stumiister]

Hydroidi
I work at a fleet trucking company so I have acess to all the fancy shop tools most guys dont, and since the boss has a A/C machine I took advantae of it, and the bosses dont mind if I work on my truck there as long as it is on my time.

 

[FordGuy100]

Mine was 2.75 lbs of R134a as well. I would assume thats what you should shoot for.

 

[stumiister]

I put in 2.75 and now I can hang swinging meat in the cab.

 

[FordGuy100]

Good deal!

 

[chris142]

Go buy the adapter for $5.00.

 

[icanfixall]

These rigs all have the same ac systems be it a single or crewcab. Hangin meat is how I drive. I really never turn off my air unless I'm strating the engine up. But even in windet I have the air on but I push it over to heat. Dry hot air is what I like.. Mostly dry cold air.

 

[chris142]

These trucks are one of the few that work great on r134a! It was 95 here today and I was showing 38 out my vents. A comparable dodge or chevy wont work worth a squat if retrofitted to r134a. We wont put r134a in a dodge or chevy as they just wont cool. They stay r12

 

[Hydro-idi]

Another helpful modification is to cut the heater hoses and install ball valves to shut the hot coolant flow to the heater core. I recently did this and my a/c is noticeably cooler

 

[stumiister]

I may put in heater valves not to make the a/c colder but if the heater core leaks or a hose ruptures

 

[MIDNIGHT RIDER]

These trucks are one of the few that work great on r134a! It was 95 here today and I was showing 38 out my vents. A comparable dodge or chevy wont work worth a squat if retrofitted to r134a. We wont put r134a in a dodge or chevy as they just wont cool. They stay r12

My wife's 1991.5 Dodge/Cummins begs to differ.

On a typical stranglingly humid 98* Kentucky day, it will pull the dairy probe zip-tied into the vent down to 30* American and chill you to the bone.

These vintage Dodge trucks blow through BOTH the evaporater and heater-core at the same time; they are not separated in isolated chambers.

It came factory-original with some silly vacuum-operated cut-off valve in the heater-hose; even brand-new, these allow about 1/4 of the coolant volume to pass through when closed.

With that silly factory valve, the vent temperatures were about 50* at best.

I tossed that mess in a sink-hole and put in a manual stainless-ball valve and that simple modification made all the difference in the world.

I have a cut-off in my 85 Ford and it also does make a difference, especially those times when it is just marginally warm enough that one would otherwise run the A/C on LOW, I can then leave the A/C OFF and be comfortable.


I would give five big hunnert-dollar bills if my Ford A/C would constantly perform as well as the A/C in her Dodge.

 

[chris142]

We always feel heater hoses to make sure that the heater valve is working Or pinch them off For testing purposes. The problem here lies with the AC condenser not being efficient enough And I can't keep the pressure down. Maybe you're 91 has an updated condenser? Maybe they were getting ready for the changeover coming in 93