I think I just blew up my A/C

[tony-muscle]

Although unlikely, a failed or plugged expansion valve could cause the pressure to build and blow the hose.

Is there a way to test for a plugged expansion valve before filling the system with refrigerant?

 

[Don C]

I am still struggling with the fact that the new green O-rings I find are metric and the unit is actually inch. When I pull a hose or connection open the green rings look horrible. Do you have place to get the inch O-rings? Putting a square peg in a round hole is just not right.

Harbor Freight has the green (HNBR) o-rings in SAE sizes, don't know if the kit has the size you need, though. I've used them on other things, like a pressure washer and airless paint compressor, without any problems.

https://www.harborfreight.com/205-piece-hnbr-o-ring-kit-67644.html

 

[73pony]

Although unlikely, a failed or plugged expansion valve could cause the pressure to build and blow the hose.

Is there a way to test for a plugged expansion valve before filling the system with refrigerant?

The only way I know how to test is with the system charged and running.

 

[tony-muscle]

Although unlikely, a failed or plugged expansion valve could cause the pressure to build and blow the hose.

Is there a way to test for a plugged expansion valve before filling the system with refrigerant?

The only way I know how to test is with the system charged and running.

Thank you Jason for all the help. I sent the hose out today for repair so it won't be until 2 weeks or so that I will get them back.

 

[tony-muscle]

I think I will leave my current A/C system but get a new Sanden compressor and bracket adapter. I think I can use my current hoses, except that I will need a longer high pressure hose, which is the one I am redoing that broke so it should be easy. I like the black one from VDF (https://www.cvfracing.com/black-sanden-style-ac-compressor-r134a-v-belt-pulley/). Sometime I will also try to get to the fan inside the car to see in what condition is it. It gets very noisy at high speed.

Do you think I need a new dryer? I had just replaced the dryer a month ago so I will think that I don't need a new one.

 

[Don C]

Whenever the system has been open for more than a few minutes the drier will start absorbing moisture out of the air, the higher the humidity, the more it absorbs. I wouldn't take a chance on it, they're not that expensive to pay for some peace of mind. If the drier cannnot pull moisture out of the refrigerant, the liquid moisture can destroy the compressor.

 

[tony-muscle]

Whenever the system has been open for more than a few minutes the drier will start absorbing moisture out of the air, the higher the humidity, the more it absorbs. I wouldn't take a chance on it, they're not that expensive to pay for some peace of mind. If the drier cannnot pull moisture out of the refrigerant, the liquid moisture can destroy the compressor.

Thanks. By the time i put it together it would have been 5-6 weeks with high summer humidity.
Sent from my SAMSUNG-SM-G930A using Tapatalk

 

[Jeff73Mach1]

Replace the dryer

 

[tony-muscle]

Replace the dryer

Out of curiosity. What is the size of the condenser that comes with the Classic Auto Air system? Is it bigger?

 

[Jeff73Mach1]

Don't recall, but as I never had air. I have nothing to compare it with

Finished up the install of the 56 F 100 yesterday-it has a smallish condensor, but worked great

 

[tony-muscle]

Don't recall, but as I never had air. I have nothing to compare it with

Finished up the install of the 56 F 100 yesterday-it has a smallish condensor, but worked great

Cool...(pun intended)! Do you have an additional electric fan or just the mechanical w/clutch?

 

[Jeff73Mach1]

neither- Just a shrouded flex fan (Yuck) It would not break 180 while moving. Hit 210 after idling for 15 minutes.

 

[tony-muscle]

Does anyone knows of an A/C vent for the center where you can adjust the horizontal direction of the louvers? What I have now allows vertical adjustment but not horizontal. I would like to have two separate vents in the center like I have, but with the horizontal adjustment capability. I notice that in my daily driver I adjust it for the air to hit right in my face until the car cools down. In the Mustang I can't get that to happen due to the lack of adjustability. I wonder if the Cougars have something like that.

Edit: I found this. I wonder if something like this will fit. However, it is ridiculously expensive.

https://secure.cougarpartscatalog.com/store/p/14604-Center-A/C-Register-Bezel-Grade-A-Used-1969-1970-Mercury-Cougar.html

 

[tony-muscle]

More thought on the RPM issue. My engine pulley is 8" and the A/C pulley 6". With that pulley ratio the compressor will hit 6,000 rpms at 4,500 engine RPMs. I believe my pulleys are stock so this can easily happen in any stock engine with A/C. The Sanden compressor has a 7,000 rpm "downshift spike" rating and a 5" pulley so it will get up there at 4,375 engine RPMs. I think a RPM switch and a high pressure switch would be helpful.

 

[Don C]

https://www.summitracing.com/parts/sum-830449-1/overview/

 

[Carolina_Mountain_Mustangs]

More thought on the RPM issue. My engine pulley is 8" and the A/C pulley 6". With that pulley ratio the compressor will hit 6,000 rpms at 4,500 engine RPMs. I believe my pulleys are stock so this can easily happen in any stock engine with A/C. The Sanden compressor has a 7,000 rpm "downshift spike" rating and a 5" pulley so it will get up there at 4,375 engine RPMs. I think a RPM switch and a high pressure switch would be helpful.

Would the pressure valve on the compressor not gone off if over pressure? On the rear bottom outside of the compressor.

 

[Jeff73Mach1]

Vintage air advertises that their Sanden Compressors are good for 6000 continuous engine RPM, Mine has spun considerably faster for brief moments without a problem. Some of the Sanden compressors are 10000 rpm capable!

 

[tony-muscle]

https://www.summitracing.com/parts/sum-830449-1/overview/

Exactly. They have another one where the LCD screen shows the RPMs. I have it in my radar screen.

More thought on the RPM issue. My engine pulley is 8" and the A/C pulley 6". With that pulley ratio the compressor will hit 6,000 rpms at 4,500 engine RPMs. I believe my pulleys are stock so this can easily happen in any stock engine with A/C. The Sanden compressor has a 7,000 rpm "downshift spike" rating and a 5" pulley so it will get up there at 4,375 engine RPMs. I think a RPM switch and a high pressure switch would be helpful.

Would the pressure valve on the compressor not gone off if over pressure? On the rear bottom outside of the compressor.

I don't know about this pressure valve. Once I remove the compressor I will look. In my case, I didn't have a high pressure type of binary switch which would have save me from trouble.

Vintage air advertises that their Sanden Compressors are good for 6000 continuous engine RPM,  Mine has spun considerably faster for brief moments without a problem.  Some of the Sanden compressors are 10000 rpm capable!

The more I think of it, the root cause of my "overpressure" situation was likely caused by overcharging the system. The RPM contributed, but it probably would have not failed if it wasn't for the overcharge condition.

 

[Jeff73Mach1]

sometime **** fails and the cause is never known. Try not to overthink it

 

[tony-muscle]

Does anyone knows of an A/C vent for the center where you can adjust the horizontal direction of the louvers? What I have now allows vertical adjustment but not horizontal. I would like to have two separate vents in the center like I have, but with the horizontal adjustment capability. I notice that in my daily driver I adjust it for the air to hit right in my face until the car cools down. In the Mustang I can't get that to happen due to the lack of adjustability. I wonder if the Cougars have something like that.

Edit: I found this. I wonder if something like this will fit. However, it is ridiculously expensive.

https://secure.cougarpartscatalog.com/store/p/14604-Center-A/C-Register-Bezel-Grade-A-Used-1969-1970-Mercury-Cougar.html

One more discovery about my A/C. I realized my center air register (now I know the right name) has the louvers reversed, meaning that they are aiming towards the middle instead of towards the driver/passenger. Who installed this thing??? :shootself:

The Shop Manual can be a wonderful thing. I will get this fixed over the winter and I may not need the adjustable register I was researching.