The problem is the cycling switch (low pressure switch on the accumulator) sticks and the Schrader valve on the high pressure line has failed.
Currently the system is running and maintiaining about 35PSI of R134a on the low side during max cool. The dust cap on the high side line is sealing the system though.
I bought a new valve (part #52545-8184) and a new cycle switch (part #5246-6358)
Problems, the valve is the core and the body. The stem is not serviceable alone. It looks like you unthread the valve from the flange on the high pressure line. But what size wrench does it take??? It is between 9/16" and 5/8" and also 15mm and 16mm. Are there special wrenches for this type of equipment?
I got the switch to work with a 7 oz ballpeen, but I'm sure it will fail again. If I'm going to take the system down I want to replace both items. FYI, the compresser and accumulator are about 10 months old.
I know about evacuating the system and purgung to remove moisture so no lectures on refer 101 please.
TIA
Posted by Hawkeye (Member # 88) on :
Just a dumb question - do you have a service manual for it? I've found my Camaro Service manual very valuable.
Posted by SSHEETS (Member # 1989) on :
quote:Originally posted by Hawkeye: Just a dumb question - do you have a service manual for it? I've found my Camaro Service manual very valuable.
No...it's my mom's truck and the AC quit. Like I said, I've got it working, but it would be wise to replace the two items listed. My mom and Dad are both retired and my dad's health is getting poor. It scares me to think of him stuck in a hot truck cab Posted by westell (Member # 2034) on :
i had this happen on my full size blazer 4x4, and it was the fan clutch, not working well at idle, but still functional.
head pressure on compressor built up, and poof, there goes all the freon.
Posted by SSHEETS (Member # 1989) on :
quote:Originally posted by westell: i had this happen on my full size blazer 4x4, and it was the fan clutch, not working well at idle, but still functional.
head pressure on compressor built up, and poof, there goes all the freon.
The system is still finctioning normal rightnow, although the cycle switch does stick occaisionaly. When I remove either the cycle switch or the high oressure access valve the freon will have to be released from the system. If I bleed it down to 15-20psi I can hopefully swap out the valve before moisture enters the system. If that doesn't work, I can borrow a vacuum pump and pump it down Posted by 2002Z4CSS (Member # 1393) on :
Tim normally you should be able to unscrew the low pressure cycling switch and only a very small amount of freon will escape. I just unscrew the switches very fast. I never heard of the schrader valve or the low pressure cycling switch sticking and I have worked on a/c systems for over 25 years. There may be a piece of compressor debris in the valve causing it to stick. If you do discharge the system, remove the orifice tube and check it for debris. It should be clean with just oil on the screen. The worst I have seen at this location was a bad o-ring on the switch or a pin hole in the schrader valve boss weld. If you unscrew the schrader valve boss then you will loose the freon charge. Any auto parts store will have R134a. With any pressure in the system,you will not get moisture in the system. That only happens on a dead system with no charge or pressure at all. If you decide to get a vacuum pump, I used to use an old refridgerator pump to vacuum the system down. After 20+ years, it finally took a dump. I just bought a nice air powered vacuum pump from Harbor Freight for $10. It takes the system to a 28.5" vacuum in just seconds. Check them out online.
Posted by Steve da Wrench (Member # 1301) on :
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