Jump to content

A/c Valve Leak


Recommended Posts

Posted

I have not checked the A/C pressure in the 4 years i have had my truck, and I thought since it seemed to be getting a little warmer I would put an A/C pressure gauge on it and top off the freon if needed. Well, needless to say the valve stuck and it is just leaking out vapor and freon now.

 

Can I change out the schrader valve or do I need to replace a heck of a lot of parts all because of this valve leaking? Any help appreciated.

Posted
I have not checked the A/C pressure in the 4 years i have had my truck, and I thought since it seemed to be getting a little warmer I would put an A/C pressure gauge on it and top off the freon if needed. Well, needless to say the valve stuck and it is just leaking out vapor and freon now.

 

Can I change out the schrader valve or do I need to replace a heck of a lot of parts all because of this valve leaking? Any help appreciated.

 

You should be able to just replace the valve, but you're going to want to put it under a vacuum afterwards to make sure no air/moisture is in the system before recharging. If you can swap it while it's leaking, then no worries, but you may have frosty fingers afterwards....

 

That definately sucks though.

  • 2 weeks later...
Posted

me too. low side valve. It seemed like the dust cap made the leak stop. Maybe it didn't and it was just quieter. In any case, anybody have experience with this? Does the tool mentioned above allow replacement of the valve core without discharging the system? Is it possible the dust cap is actually containing the low side pressure?

Posted

The valve insert is the same as tires use and the tire tool works. Usually, these valve pins just get stuck and jiggering it lets it seat perfectly. Rarely do you need to replace the insert. The cap is the real seal. These also do not leak if the oring is ok.

 

Ken

Posted

The high side uses a ball seal. After the system has been ran for several months. Once you clip on be prepared for the horror.... The coupler usually wreck the ball and requires that you replace the fitting. Four Seasons 409-521 (I think, I remember that right, that should be the NAPA number)...

 

It requires you drain (recover........ vent) R134a. Then remove the fitting and also replace the low side if necessary...... While doing this you should know that you NEED TO VACUUM THE SYSTEM back down to remove moisture. 1 hour of vacuum, will do the trick nicely. Get new caps also, as ken said above that really seal it all off good....

 

If the system has not been preforming well, might not be a bad idea to change the orifice tube while your at it...

 

I have no less than 4 of these fittings in my tool box.... It is a frequent problem. And if you don't vacuum it down shame shame shame.... You just introduced moisture into your system. It has now began the death dance.

 

Jbo

Posted
The high side uses a ball seal. After the system has been ran for several months. Once you clip on be prepared for the horror.... The coupler usually wreck the ball and requires that you replace the fitting. Four Seasons 409-521 (I think, I remember that right, that should be the NAPA number)...

 

It requires you drain (recover........ vent) R134a. Then remove the fitting and also replace the low side if necessary...... While doing this you should know that you NEED TO VACUUM THE SYSTEM back down to remove moisture. 1 hour of vacuum, will do the trick nicely. Get new caps also, as ken said above that really seal it all off good....

 

If the system has not been preforming well, might not be a bad idea to change the orifice tube while your at it...

 

I have no less than 4 of these fittings in my tool box.... It is a frequent problem. And if you don't vacuum it down shame shame shame.... You just introduced moisture into your system. It has now began the death dance.

 

Jbo

 

I agree 100%, except in the case where the system still has positive pressure in it, and the tool referenced above is used. That tool allows the valve to be replaced while the system is pressurized, and no moisture is introduced to the system. If however, all pressure has already escaped, then the system needs to have a vacuum pulled on it.

 

I can't believe I am up this early to go fishing... While playing golf on Sunday, one of the guys that joined our group said that anyone that went fishing must have absolutely nothing else to do. He's now going fishing with us today :D

Posted
The high side uses a ball seal. After the system has been ran for several months. Once you clip on be prepared for the horror.... The coupler usually wreck the ball and requires that you replace the fitting. Four Seasons 409-521 (I think, I remember that right, that should be the NAPA number)...

 

It requires you drain (recover........ vent) R134a. Then remove the fitting and also replace the low side if necessary...... While doing this you should know that you NEED TO VACUUM THE SYSTEM back down to remove moisture. 1 hour of vacuum, will do the trick nicely. Get new caps also, as ken said above that really seal it all off good....

 

If the system has not been preforming well, might not be a bad idea to change the orifice tube while your at it...

 

I have no less than 4 of these fittings in my tool box.... It is a frequent problem. And if you don't vacuum it down shame shame shame.... You just introduced moisture into your system. It has now began the death dance.

 

Jbo

 

I agree 100%, except in the case where the system still has positive pressure in it, and the tool referenced above is used. That tool allows the valve to be replaced while the system is pressurized, and no moisture is introduced to the system. If however, all pressure has already escaped, then the system needs to have a vacuum pulled on it.

 

I can't believe I am up this early to go fishing... While playing golf on Sunday, one of the guys that joined our group said that anyone that went fishing must have absolutely nothing else to do. He's now going fishing with us today :fingersx:

 

 

GM does not have a valve core on the high side. They use a ball seal.... It requires complete replacement..... TEM 409521 (GM High Side Most vehicles all GMT-800's) you can not leave the pressure in the system and change this. Low side is a valve stem. Most leaks on GM's is the high side.

 

JBo

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Forum Statistics

    250.4k
    Total Topics
    2.7m
    Total Posts
  • Member Statistics

    342,840
    Total Members
    8,960
    Most Online
    appletrav
    Newest Member
    appletrav
    Joined
  • Who's Online   1 Member, 0 Anonymous, 376 Guests (See full list)

  • Latest Articles

  • Posts

    • This is a 1/2 ton thing ONLY.  All HDs 2020-2026 have the two speed transfer case, with Autotrac as an option.     1/2 tons 2019-2026, regular 4x4s come with a single speed case (no 4LO!), and trucks with Z71 ordered, or all Trail Boss trucks come with the 2 speed case.  2 speed case is also an option on WT, and is also standard on High Country.  
    • 2013 5.3 still to this day calls for the PF48 filter.  Which as a 15psi bypass pressure.     There is a TSB, 17-NA-157 that talks about the PF-63 and PF-64 filters which have a higher bypass rating of 22psi.    TSB HERE - temp.xml   "Beginning in 2012, the oil pumps began to regulate main gallery feedback instead of pump out pressure. This means that the oil pump now does not begin to regulate until pressure is built up to the main gallery. This change reduces the amount of time it takes to provide oil to the engine bearing and lifters during extreme cold start conditions.  Main gallery feedback oil pump control systems are present on the following engine families which use Spin-on oil filters: Small Gas Engine (SGE), Large Gas Engine (LGE), High Feature (HFV6) Gen2 and Small Block Gen5 gasoline engines. These engines with the main gallery feedback oil pump control systems are factory built with an ACDelco® oil filters"   It also calls out what engines use those filters.  The gen 4 small blocks were not on that list (LMG, LC9, L9H, L92, L94, L20, L96).  Gen 5 small blocks use the higher pressure filter.          That all said...   Your 7045 Napa filter is the PF63 equivalent, with 22psi bypass.  You are already using the higher bypass pressure filter.  You CAN keep using it, you don't technically have to use it though.  
    • Do you know WHY the filter relief setting was increased to 22 psig?    When the new system goes into the second stage the pump volume ramps up considerably. It was found that the 15 psi filter bypass setting put the filter in bypass on a warm engine when the second stage was activated. Raising the filter bypass setting forced the filter to do what it designed to do. Filter. Preventing debris from circulating during high load, high rpm operation.    So next question is how did GM find this out? VLOM/lifter failures and a deep dive by Melling Corp.    Last question. Is it required? Look at it like this; a motor may be equipped with a rev limiter. But it only works if the set point in reached. That 22 psig setting only matters if the pressure differential across the filter media exceeds 15 psig during normal warm operation. Second stage kicks in around 3000-3500 rpm.    I can't answer your question because I don't know you and how you use the truck. But I think there is enough information here to let you decide for yourself. 😉
    • Probably not their first rodeo, so it should go as planned most likely.  Typically the service manager or tech doing the swap will put some seat time to shake it down after they get it all put back together.  We usually put 50-100mi before we hand them back so if something happens, its not after you get it.  A coolant leaks, oil leaks, a ground left off or loose, vibration, etc.     The new engines so far have been good?  There's been a couple that have popped out there again (the replacement engine) but most have been okay.  
  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...