1987 Buick Grand National R12 charge

[tbirdtbird]

Well, we already know we are not getting the full benefit of the condenser, based on the water test.
Pressures at idle or even 1000 RPM are just not helpful, we need 1500-1800 RPM to get a better handle on what is going on. A comp does very little work at lower rpms and the system cannot be judged.
By now you should be a pro at the required conditions....

Recirc, max fan, max cool, doors open (ie a full load test) is what is needed

Are you able to get your fingers on the pipe into (after TXV) and out of the evap and compare? Pipe out should be the same or colder
We asked this question before but it was never answered

[Ajrothm]

Well, we already know we are not getting the full benefit of the condenser, based on the water test.
Pressures at idle or even 1000 RPM are just not helpful, we need 1500-1800 RPM to get a better handle on what is going on. A comp does very little work at lower rpms and the system cannot be judged.
By now you should be a pro at the required conditions....

Recirc, max fan, max cool, doors open (ie a full load test) is what is needed

Are you able to get your fingers on the pipe into (after TXV) and out of the evap and compare? Pipe out should be the same or colder
We asked this question before but it was never answered

Yeah I checked the pressures with the engine revved up to about 2500 rpms or so. Yesterday they went to about 31l/250h... but it was only about 87* degrees in the garage. When I tried this test back in may, I saw about 37l/300h on a 98* day with it really heat soaked, if I recall.

As for the piping in/out of the evaporator, it’s mostly covered but I may be able to get a finger on it. I’ll check today.

The suction line definitely gets cold. When I first opened the hood after a 30 min drive, the suction line almost had frosty fog on it before it was sweating.

I tried to upload pics of my gauges, thermometers etc but the forum won’t let me load them. The files are all too large.

The system pressure with the engine of was about 65/65 at 86* which seems a little low compared to the charts I see online. But back in may it was 75/75 at 90* so I’m not sure if it’s a little low or not.

I have been testing the system in Max, blower speed on the 3rd speed and doors shut.

If I tested it with the doors open and blower on high, I doubt it would get below 65* in the vents.

Just the blower on high seems to overwhelm the evaporator and raises the vent temps to 56-58* from about 49-50* at the 3rd speed.

[JohnHere]

I tried to upload pics of my gauges, thermometers etc but the forum won’t let me load them. The files are all too large.

As an aside, my camera usually saves photos anywhere from 2MB to 4MB, but the maximum photo size on this Forum is 256K. The best way I've found to have the system accept photos is to download a compression app and use it to re-size them. The free Android app that I use has an option to re-size images to 250K, just under the maximum. I've used this app several times without any problems or degradation of image quality.

[tbirdtbird]

If you are using any ver of Windows, the included app Paint will resize nicely for you. Look for the "resize/skew" icon

[Ajrothm]

I tried to upload pics of my gauges, thermometers etc but the forum won’t let me load them. The files are all too large.

As an aside, my camera usually saves photos anywhere from 2MB to 4MB, but the maximum photo size on this Forum is 256K. The best way I've found to have the system accept photos is to download a compression app and use it to re-size them. The free Android app that I use has an option to re-size images to 250K, just under the maximum. I've used this app several times without any problems or degradation of image quality.

Thanks man. I’ll look for an app. I’m using an iPhone so I’ll have to find something apple based. I’ll look into it.

[tbirdtbird]

From Google, your best friend
"Can I resize a photo in Apple photos?
In the Preview app on your Mac, open the file you want to change. Choose Tools > Adjust Size, then select “Resample image.” Enter a smaller value in the Resolution field. The new size is shown at the bottom."

[Ajrothm]

Ok starting now.

Engine cold/not running static test. 90L/90H at 92* ambient.

Going for a good 30 min drive now to get the system food and heat soaked, then I’ll throw the gauges in it without shutting it off and get some hot readings and go from there. Will report back asap .

[Ajrothm]

Pic test..

Frosty suction line after 30 min drive.

[Ajrothm]

Ambient temp at the radiator. 94* outside but hotter in the garage.

[Ajrothm]

Idle at around 1000 rpms, AC on Max, doors shut, fan speed on 3. Vent temp around 53*.