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You need to jumper the low pressure switch (unplug the connector and jumper across the terminals) so the compressor will run and take in more refrigerant.
Once there is sufficient charge in the system (say your reading 30 psi on the low side at 1000 rpm) you can remove the jumper and plug the connector back in, and continue charging until you have added the full amount (about 36oz if I recall).
It looks like everything is hooked up correctly, it's been over an hour and it's still holding almost 30" of mercury.
The only hickup was the low site quick connect adapter on the accumulator. The was already an needle valve thing in the accumulator that I had to remove before i could screw on the adapter.
If the "needle valve thing" your referring to is the "Schrader Valve", you need to leave that in. That is what seals the port when you remove the cutoff valve or gauge hose. I don't know what you mean by "adapter" - if you mean the hose fitting adapter and this adapter will remain on the truck, and the adapter has a Schrader valve in it so you can remove the gauge hose - then okay. But before you fully charge the system, be sure there is a Schrader valve somewhere in the chain to retain the charge.
BTW - I hope this is obvious - but never open the high side valve on the gauges while charging (that would overpressure the R134 can). Only open low side.
I'm ready to refill, anyone know how much R134a it takes?
The system holds 48oz of R12, and converting to R134a you put in "up to" about 80% of the original charge. So that's 36 - 38oz of R134.
You need to jumper the low pressure switch (unplug the connector and jumper across the terminals) so the ciompressor will run and take in more refrigerant.
Once there is sufficient charge in the system (say your reading 30 psi on the low side at 1000 rpm) you can remove the jumper and plug the connector back in, and continue charging until you have added the full amount (about 36oz if I recall).
Ok, got it. Will try that when I get home from work, thanks.
Originally Posted by CountryBumkin
If the "needle valve thing" your referring to is the "Schrader Valve", you need to leave that in. That is what seals the port when you remove the cutoff valve or gauge hose. I don't know what you mean by "adapter" - if you mean the hose fitting adapter and this adapter will remain on the truck, and the adapter has a Schrader valve in it so you can remove the gauge hose - then okay. But before you fully charge the system, be sure there is a Schrader valve somewhere in the chain to retain the charge.
BTW - I hope this is obvious - but never open the high side valve on the gauges while charging (that would overpressure the R134 can). Only open low side.
The system holds 48oz of R12, and converting to R134a you put in "up to" about 80% of the original charge. So that's 36 - 38oz of R134.
The new accumulator low side port already had a Schrader valve in it, and then I pulled the quick connect hose fitting adapter (yes, it will stay on the truck) off the old accumulator and tried to put it on the new accumulator, but the adapter also had a Schrader valve. I had to pull the valve on the accumulator, two Schrader valves in series were not working well together. That seems painfully obvious now, but I didn't know you could remove them, so originally I just thought that when you push the needle on the top one it pushes the needle on the next one underneath it. Wasn't until I was at the auto parts store and saw replacement Schrader valves with a little T-handle removal tool in the help section that it dawned on me that maybe they weren't supposed to work in series like that.
Also installed the heater core shut off valve. Not entirely sure which hose was in and which one was out, but one of the two was already split with a male to male splice connector and hose clamps so I just pulled that out and stuck the valve in its place.
I put a tee in the vacuum line going to the inside/outside air servo over by the pass side hood hinge. This servo gets vacuum only when the lever inside is on "max". We had a thread on this, and I think Gary found a un-used port on the slide lever in the dash that he was going to cut open and use that, even though he would have to run another vacuum line out under the hood.
They have electrical solenoids that will control vacuum if you wanted a separate switch on the dash. The way I did it was quick and easy.
I knew of the post for the vacuum line I meant the heater hoses.
Dave - - - -
Great news, CountryBumkin's jumping the terminal trick worked, she's blowing cold air for the first time in at least 7 years (she sat up for 5 years before I bought her and I've owned her for 2 now).
Notice the beautiful condensation behind the beautiful lady on the window from the cold a/c!
I was losing a lot of cold air around the evaporator coil box into the engine compartment so I taped the seams as best I could with this aluminum HVAC tape stuff.
Not sure how well this will hold up but I figured it was worth a try.
The only issue is that it blows blows about 10% out the vents, 20% out the dash/defroster/windshield vents and the other 70% out the floor here:
Id like to get more air to the dash vents, but I'm tickled pink just like it is!
Gary has a drawing of the HVAC ducting on his website A/C & Heater - ???Gary's Garagemahal
Note which "doors" may be not closing or sticking, and check them to see if they are getting vacuum when they should. For example the "Floor/defrost door" may not be closing because the vacuum hose to it may be cracked/leaking.
If the vacuum hoses from the EGR system were any indication, I'm sure these are bad, too. If my work schedule lightens up I'm going to try to take care of this this week, I had to drive all the way to work with the windshield wipers on because it was blowing cold air through the defroster in covering the windshield with condensation. Not that I'm complaining, I'll take this problem over the no AC problem any day!
If the vacuum hoses from the EGR system were any indication, I'm sure these are bad, too. If my work schedule lightens up I'm going to try to take care of this this week, I had to drive all the way to work with the windshield wipers on because it was blowing cold air through the defroster in covering the windshield with condensation. Not that I'm complaining, I'll take this problem over the no AC problem any day!
I hear ya!
It's pretty easy to see and work on the AC duct system if you remove the dash pad and radio.
I hope mine turns out as well when I get mine working again.
IIRC they use short rubber hose to join the longer plastic lines and it is the plastic line that break from age.
Till you get time to check the duct work place a towel covering the glass
Pulled over, let it cool down and started it back up. Drove for a couple minutes and the temperature started creeping up again. Just because the only thing that I knew that changed lately with the air-conditioner, I turn the air conditioner off and danged if the temperature didn't go back down to just a little above normal.
Make sure your fan is working. AC adds heat load as the condenser is mounted in front of the radiator so the heat is added to radiator load.
Does it stay in the Normal range as long as the truck is moving (air flow through radiator)? If yes, you may find that the fan clutch is not working properly.
I added an electric fan to my setup - because my AC pressure was going to high while sitting still (not enough air flow) and the AC high pressure discharge opened, however my radiator temp was never a problem. When I added the fan (to come on with AC) my AC high side pressure dropped about 25 or 30 psi while sitting still.
I would not believe that gauge. A poor ground to the cab sheetmetal can cause that. If you want to know what the temp of the engine is, go get a set of gauges at the store with numbers on them and use them to troubleshoot with.
I would not believe that gauge. A poor ground to the cab sheetmetal can cause that. If you want to know what the temp of the engine is, go get a set of gauges at the store with numbers on them and use them to troubleshoot with.
I'm not sure a new set of gauges is warranted just yet. Personally, I've found the factory gauges to be extremely consistent. My temp gauge, for example, usually sits at the O (in Normal) once the engine is warmed up. Now is that 180 or 200 or who knows what? Heck if I know, but if the needle climbs much above the O, I know I've got a potential problem looming.
Also, when the temp gauge was climbing, was the new heater shutoff closed? In theory it shouldn't change anything, but maybe it affected flow elsewhere. It's easy enough to check. Don't make any other changes and open up that valve. Go for a test drive, duplicating the overheat conditions as much as possible, and see what happens.
