Help converting ‘92 to R134

[Ranger305]

I have rebuilt my ac system and am converting to R134. The low side adapter works fine, but the new high side hose has a male M10 port. What do I need to do to to adapt this to the 134 gauges so I can vacuum and fill this thing?

 

[adsm08]

Nothing.

Generally, unless you have a machine with a pump that can force the refrigerant in all vacuum, evacuating and charging are done through the low side port. That way you only have to overcome 30 some PSI, and not a +100.

The high side port is more for diagnostic readings.

 

[Ranger305]

So I don't need to vacuum the high side? The system was opened to replace ththe accumulator and suction/discharge hose?

I think I'm looking at the high side port, it's near th he compressor in the suction/discharge hose between the compressor and the condenser?

 

[Denisefwd93]

So I don't need to vacuum the high side? The system was opened to replace ththe accumulator and suction/discharge hose?

I think I'm looking at the high side port, it's near th he compressor in the suction/discharge hose between the compressor and the condenser?

if you have an older Ranger that hi side port was actually put there for charging refrigerant at the factory it has a little rubber poppet and is easily dislodged charging hose Schrader depressor. You can pull the whole vacuum through the low side or the high side, don't have to do both.

Oops, I should learn to read before I respond because it's one of my big complaints about other people I see you did replace the hose you need R134a charging connectors for your hoses,

 

[Ranger305]

My problem seems to be that there is no adapter I can find to go from this M10 male fitting to a r134 fitting. If vacuum of high side isn't necessary, I dont need to adapt it.

 

[Denisefwd93]

My problem seems to be that there is no adapter I can find to go from this M10 male fitting to a r134 fitting. If vacuum of high side isn't necessary, I dont need to adapt it.

You have a picture? Sounds like you're describing the high pressure switch connection, it could be on the muffler or could be on the hose, depending on the makers of the hose set.

 

[Ranger305]

It's the port in the lower left of your pic, on the silver cylinder. My hose doesnt have the port at the end of that hose where it has the slip connector.

 

[Denisefwd93]

That's the high pressure cutout switch connector

It's the port in the lower left of your pic, on the silver cylinder.

 

[Ranger305]

This truck has never had anything in that port, I always assumed it was the high side service port. I can't find any other port on it outside of the low side port on the accumulator. Is it possible there isn't a high side service port? Sorry if these are dumb questions, I'm learning a lot from this.

Not questioning Adam's info above, but trying to understand this system better as I've always thought yo have to vacuum each side from their respective ports, but it looks like you work strictly with the loe side port on this truck.

Also, there is a brass button on the high side of the block on the back of the compressor. What is its purpose? Looks like a plug with a vent in it. No threads or any th hinges exposed.


This is what my hose looks like: https://m.ebay.com/itm/A-C-Manifold...6hbG4JQ:sc:ShippingMethodStandard!37174!US!-1

 

[Denisefwd93]

This truck has never had anything in that port, I always assumed it was the high side service port. I can't find any other port on it outside of the low side port on the accumulator. Is it possible there isn't a high side service port? Sorry if these are dumb questions, I'm learning a lot from this.

Not questioning Adam's info above, but trying to understand this system better as I've always thought yo have to vacuum each side from their respective ports, but it looks like you work strictly with the loe side port on this truck.

Also, there is a brass button on the high side of the block on the back of the compressor. What is its purpose? Looks like a plug with a vent in it. No threads or any th hinges exposed.


This is what my hose looks like: https://m.ebay.com/itm/A-C-Manifold...6hbG4JQ:sc:ShippingMethodStandard!37174!US!-1

Do you have guage hoses with134 service connectors blue & red? or quarter inch flare guage hoses?

On the back of the compressor block, the brass button is a relief valve, the silver cylinder is a muffler, that connector is generally for high pressure cutout switch that you may not need or have on your older truck.

you should be able to find 134 hose service connectors & adapters

No, you don't have to draw from both sides, it's faster from both sides, but from the low side will do the job.

 

[Ranger305]

Yes, I am doing the Loan-A-Tool at a local parts store to get r134 gauges and a vacuum pump.

Good info on the relief valve and muffler. That also explains the vacuuming as well. I have an adapter on my low side port, so I should be good to go as soon as I pick up the gauges and pump again.

Many thanks to both of you for educating me on this! I def understand the how and why much better now.

Believe it or not, the system was completely intact until last year when I pulled too hard on the discharge hose while replacing the engine and cracked it. I've owned this truck since 1995.

 

[Denisefwd93]

Yes, I am doing the Loan-A-Tool at a local parts store to get r134 gauges and a vacuum pump.

Good info on the relief valve and muffler. That also explains the vacuuming as well. I have an adapter on my low side port, so I should be good to go as soon as I pick up the gauges and pump again.

Many thanks to both of you for educating me on this! I def understand the how and why much better now.

Believe it or not, the system was completely intact until last year when I pulled too hard on the discharge hose while replacing the engine and cracked it. I've owned this truck since 1995.

Just a couple things to take note about when you put a vacuum on it.
The new low side hose May collapse so don't be alarmed about that, also if you're not going to use the Schrader high pressure cutout connector make sure to plastic cap is on it lest the vacuum leak through the schrader, when you pull from the low side,

Assuming you flushed and replaced the oil you should be good to go when you get it charged up!

 

[Ranger305]

So I pulled a vacuum on it for 3 hours, unhooked everything and let it sit for a couple days. Went out this afternoon, hooked the gauge up (can't connect high side) and it still had the same vacuum reading so I charged it.

When I put it together, I added a 7oz bottle of PAG46. It also had 1oz of some coolant helper and the way I read the bottle, treat it as 7oz. According to the charts, the truck took 36oz of R12 and 7oz of Oil. I added three 12oz can of R134. The can tap had a leak I didn't catch until the first can was half empty, so I may have lost an oz or two. It took much longer for the last can to empty compared to the first two. Low side pressure with AC on high sits right at 45psi stable. Ambient temp is 80deg. Chart says it should be between 40 and 50psi.

In running it for 30min or so, the compressor never kicked off. I pulled the compressor wiring lead to make sure the clutch wasn't stuck and it kicked off immediately and the pressure rose to 85psi. Temp at the vents was about 54deg.

Should the compressor not cycle occasionally?

 

[Denisefwd93]

Seems like you got it first attempt congratulations! they usually short-cycle when it's below 70 like in the morning when it's really cool. The Cycles get longer and longer as refrigerant starts to percolate, it doesn't work fast like the old R12 did,

So I pulled a vacuum on it for 3 hours, unhooked everything and let it sit for a couple days. Went out this afternoon, hooked the gauge up (can't connect high side) and it still had the same vacuum reading so I charged it.

When I put it together, I added a 7oz bottle of PAG46. It also had 1oz of some coolant helper and the way I read the bottle, treat it as 7oz. According to the charts, the truck took 36oz of R12 and 7oz of Oil. I added three 12oz can of R134. The can tap had a leak I didn't catch until the first can was half empty, so I may have lost an oz or two. It took much longer for the last can to empty compared to the first two. Low side pressure with AC on high sits right at 45psi stable. Ambient temp is 80deg. Chart says it should be between 40 and 50psi.

In running it for 30min or so, the compressor never kicked off. I pulled the compressor wiring lead to make sure the clutch wasn't stuck and it kicked off immediately and the pressure rose to 85psi. Temp at the vents was about 54deg.

Should the compressor not cycle occasionally?

 

[Ranger305]

Thanks! That was an interesting process. No we'll see how long this 26 year old compressor makes it and go enjoy some cool air on the hottest days.