THEMCGUIRE
1/2 ton status
Safer anyway. I vacuumed the system and letting it sit overnite we will see tomorrow if my vacuum holds.
Thanks for the support.
Thanks for the support.
CK5
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1988 K5 Air Conditioning Upgrade ?
- Thread starter THEMCGUIRE
- Start date
should hold vacuum for 30-45 minutes...leave the Schrader valve in..
are you using correct pressure switch at the dryer? need one for r134a...
did you put in new orifice tube in proper location?
pressure switch...
orifice tube...
are you using correct pressure switch at the dryer? need one for r134a...
did you put in new orifice tube in proper location?
pressure switch...
orifice tube...
did the cans get cold at all while filling...?
THEMCGUIRE
1/2 ton status
I messed up
It was the double scrader valves that messed me up. I removed the one that came with the drier, re vacuumed and gas started going in fast, cans got real cold!
However,
the reason my a/c originally failed was the high pressure line going from the condenser to the evaporator broke somehow. Not finding a replacement I took it to a hydraulic hose repair ship and they "fixed" it.
When I started adding R134a after removing the EXTRA scrader valve, Gas started escaping from the "repaired" line fitting. On checking I found that they repaired it using a smaller piece of pipe.
Since then I found that LMC had a replacement all along and I ordered it.
BUT, I did not know about replacing the pressure switch. Duh...
now how do I find the part number for a pressure switch that is for 134a ?
During my search for the part number I found this page, very interesting http://www.e38.org/pparish/gm-rp.htm
==========================================================================================
So, I found part number, it is Four Seasons part 36674... it turns off at 21 PSI and turns on at 42 psi. Per various ads it will fit my 1988 K5. around 18 bucks!
============================================================================================
It was the double scrader valves that messed me up. I removed the one that came with the drier, re vacuumed and gas started going in fast, cans got real cold!
However,
the reason my a/c originally failed was the high pressure line going from the condenser to the evaporator broke somehow. Not finding a replacement I took it to a hydraulic hose repair ship and they "fixed" it.
When I started adding R134a after removing the EXTRA scrader valve, Gas started escaping from the "repaired" line fitting. On checking I found that they repaired it using a smaller piece of pipe.
Since then I found that LMC had a replacement all along and I ordered it.
BUT, I did not know about replacing the pressure switch. Duh...
now how do I find the part number for a pressure switch that is for 134a ?
During my search for the part number I found this page, very interesting http://www.e38.org/pparish/gm-rp.htm
==========================================================================================
So, I found part number, it is Four Seasons part 36674... it turns off at 21 PSI and turns on at 42 psi. Per various ads it will fit my 1988 K5. around 18 bucks!
============================================================================================
Last edited:
THEMCGUIRE
1/2 ton status
So I ordered it and am waiting for it and then when outside and looked at my stock switch.
Damn, it has an adjustment screw between the terminals. 1/4 turn to the left and it lowers pressure 4 psi.
Boy can I waste money.
Damn, it has an adjustment screw between the terminals. 1/4 turn to the left and it lowers pressure 4 psi.
Boy can I waste money.
THEMCGUIRE
1/2 ton status
Not done yet.
I had major trouble getting the old orifice tube out. In the end I bought a 5/16 long screw and wrapped it in paper towel so it would just slide into the evaporator and keep it centered. Then screwed it in and put a box wrench around the head. Hit it with a plastic hammer and it pulled the old orifice tube out.
After a good flushing, I am now attempting to install my third NEW orifice tube. My 1st one was a variable type. 30 bucks wasted. Switched to the $2.98 stock type. They will not go all the way in. So I pulled the evaporator last nite. The bottom tube of the evaporator has a slight bend in it, about 1/2" above the 3 indentations that prevent the orifice tube from going in too far. This bend is preventing the tube from going all the way in.
I tried to straiten it out but I guess you need special tools to fix this. Next I tried to heat the tube, hoping for some temporary expansion, still does not fit.
I have given up and ordered a new evaporator from NAPA. $135 bucks. About to go pick it up then we will see.
So this means that except for the two hoses to and from the compressor I will have replaced the entire A/C system. It had better work!!!!!!!
Will advise.
I had major trouble getting the old orifice tube out. In the end I bought a 5/16 long screw and wrapped it in paper towel so it would just slide into the evaporator and keep it centered. Then screwed it in and put a box wrench around the head. Hit it with a plastic hammer and it pulled the old orifice tube out.
After a good flushing, I am now attempting to install my third NEW orifice tube. My 1st one was a variable type. 30 bucks wasted. Switched to the $2.98 stock type. They will not go all the way in. So I pulled the evaporator last nite. The bottom tube of the evaporator has a slight bend in it, about 1/2" above the 3 indentations that prevent the orifice tube from going in too far. This bend is preventing the tube from going all the way in.
I tried to straiten it out but I guess you need special tools to fix this. Next I tried to heat the tube, hoping for some temporary expansion, still does not fit.
I have given up and ordered a new evaporator from NAPA. $135 bucks. About to go pick it up then we will see.
So this means that except for the two hoses to and from the compressor I will have replaced the entire A/C system. It had better work!!!!!!!
Will advise.
There is a repair kit for the evap inlet that holds an orifice tube. You cut the old line and this piece goes on with a compression fitting. They are normally in-stock at parts stores and reasonably priced.
And I know that I've posted before about the stock pressure switch being adjustable. You just have to read CK5 more.
Next time I have to take mine apart, I want to add a double switch on the high pressure port. I've spotted these on other vehicles. There are two temperature switches on them - a high pressure safety switch (probably N/C) and a fan cycling switch (probably N/O). Then the cooling fans should run only when the condensor gets hot, which could save gas (and relay contacts!) in the summer and aid the defrost in the winter.
And I know that I've posted before about the stock pressure switch being adjustable. You just have to read CK5 more.
Next time I have to take mine apart, I want to add a double switch on the high pressure port. I've spotted these on other vehicles. There are two temperature switches on them - a high pressure safety switch (probably N/C) and a fan cycling switch (probably N/O). Then the cooling fans should run only when the condensor gets hot, which could save gas (and relay contacts!) in the summer and aid the defrost in the winter.
THEMCGUIRE
1/2 ton status
Now you tell me.... 
THEMCGUIRE
1/2 ton status
a/c now working getting less than 50 degrees with a/c on max parked.
Not drivable yet.
Blue gauge reads 30 psi. Red gauge reads about 175 psi.
I found that my low pressure adapter had a rubber washer inside that was ripped. Replaced it and that solved the problem.
Thanks for the help.
Not drivable yet.
Blue gauge reads 30 psi. Red gauge reads about 175 psi.
I found that my low pressure adapter had a rubber washer inside that was ripped. Replaced it and that solved the problem.
Thanks for the help.
...just in time for Fall!...
(I'm laughing WITH you, not at you)...
(I'm laughing WITH you, not at you)...
THEMCGUIRE
1/2 ton status
Getting closer and closer to my move to Vegas. I am now prepared...
