The system is actually a loop, pulling vacuum from either side does not matter. I don't know why the high side moved, but they are connected by way of the system loop.
Good info, Thanks. So from other videos there are comments that using shop air to pressurize the system will put moisture into the system. Which will eventually cause problems. I am guessing (if there is a leak) using a vacuum would also bring outside air into the system, maybe not as much moisture as compressed air. But not sure if that would cause any problems later. Also note that the high side pressure on most vehicles can be 150+ psi. So the vacuum pump is not simulating actual conditions. My amateur conclusion - use the vacuum pump to test for major leaks. If no major leaks put freon in the vehicle with dye and look for smaller leaks, the 30psi vacuum may not find smaller leaks. And note most pro AC shops will not just replace one O ring, they will only replace all the gaskets with the idea if 1 9 year old gasket is bad, and the system has been empty for some time, when fully pressurized the other rubber O rings will fail.
I know you commented awhile ago but better late than never The valves on the manifold gauge set close clockwise The valves on the couplers close counter-clockwise
A vac leak test is exactly how ac manufacturers indicate. The code specifies a much deeper vacuum using a mic gauge down to a min 250mic and a decay to less than 500mic over 45min. The more time allowed the more certain you can be. if it fails the vac test then you need to pressurize and hunt for the leak.
Im just doing this for the first time myself and here is what I did: I connected the vacuum pump and did the leak test on the hose manifold itself, by opening different valves one by one and run the pump. i had to tighten up a few connections, then i held vacuum fine. the connections are supposed to be tight due to the gaskets, you do not need to screw them down hard
@@criticaljim1 yeah I did mine also and I got it working, I didn't have one of the lines attached to the compressor correctly on because the bolt that came with the compressor I bought was a little bit too long. Once I figured that out I used the old bolt and then it tightened down and got a good vaccuum it wasn't the pump hoses, but I didn't know because I had just bought that brand new on ebay.
The person in this video apparently used masking tape to mark where the vacuum reading was at instead of writing it down; He will check back after a while and make sure it stays the same, where the tape is marked.
The system is actually a loop, pulling vacuum from either side does not matter.
I don't know why the high side moved, but they are connected by way of the system loop.
Can I use this if I used stop leak in my system?
@@user-ix2uv9er1v I never use stop leak in an AC system, I believe in repairing.
Most leaks are the o-rings, they are cheap.
Good info, Thanks. So from other videos there are comments that using shop air to pressurize the system will put moisture into the system. Which will eventually cause problems. I am guessing (if there is a leak) using a vacuum would also bring outside air into the system, maybe not as much moisture as compressed air. But not sure if that would cause any problems later.
Also note that the high side pressure on most vehicles can be 150+ psi. So the vacuum pump is not simulating actual conditions.
My amateur conclusion - use the vacuum pump to test for major leaks. If no major leaks put freon in the vehicle with dye and look for smaller leaks, the 30psi vacuum may not find smaller leaks.
And note most pro AC shops will not just replace one O ring, they will only replace all the gaskets with the idea if 1 9 year old gasket is bad, and the system has been empty for some time, when fully pressurized the other rubber O rings will fail.
Good idea to test each side for leaks individually.. as I only tested on both side together. This will cut my search by 50% almost :-) thanks.
Will this work to fund a leak in the evaporator coil? My understanding is the valve to the evaporator is closed when the car is not running.
Ivf v..
Can I use this if I used stop leak in my system?
you could try, but sometimes Stop Leak will mess up some lines and seals, so keep an eye on it for the next coming months
Which way is open or close?
I know you commented awhile ago but better late than never
The valves on the manifold gauge set close clockwise
The valves on the couplers close counter-clockwise
Vacuum testing an ac system is the worst way to test for leaks.
No it’s the best bro. Do you understand science
You can test FOR leaks, but locating leaks requires different methods
And when amicronpucture leaves the flap you will miss it every time. Science. Nitrogen pressure will show you the leak. Science
@@joeviragh8721Didn’t you read what revert2625 said??
A vac leak test is exactly how ac manufacturers indicate. The code specifies a much deeper vacuum using a mic gauge down to a min 250mic and a decay to less than 500mic over 45min. The more time allowed the more certain you can be. if it fails the vac test then you need to pressurize and hunt for the leak.
even used an Audi 2.0T .. same Ac im working on lol.
I just replaced multiple components & now have no vacuum at all. I don't know where or how to start. This didn't help.
how do you know if the gauge hoses are leaking where the are connected and no the actual car a/c system?
Im just doing this for the first time myself and here is what I did: I connected the vacuum pump and did the leak test on the hose manifold itself, by opening different valves one by one and run the pump. i had to tighten up a few connections, then i held vacuum fine. the connections are supposed to be tight due to the gaskets, you do not need to screw them down hard
@@criticaljim1 yeah I did mine also and I got it working, I didn't have one of the lines attached to the compressor correctly on because the bolt that came with the compressor I bought was a little bit too long. Once I figured that out I used the old bolt and then it tightened down and got a good vaccuum it wasn't the pump hoses, but I didn't know because I had just bought that brand new on ebay.
"Wanna open these up" *proceeds to turn valves to the right* Or am I missing something?
If you are reading this do not and I repeat do not use his techniques hes just jelly Firestone graded him after he fd it up himself
very useful
Um. 20 inches of Mercury is not enough for an ac system to evacuate all the air
That’s what I wa staining. I was at 28 and kept going
30 or 29
Awesome. Thank you
Worthless video.
You did not show how to find a leak.
Why the tape
The person in this video apparently used masking tape to mark where the vacuum reading was at instead of writing it down; He will check back after a while and make sure it stays the same, where the tape is marked.
Good idea. Im going crazy if the gauge moved or not. Going blind almost 😂
This guy has no idea.
seems to have a good idea to me ! why do you say that?
do you have vids on yt ?
@@blisterj used wrong gauges
I couldnt get past how long his finger nails are.... 💅