Automotive Air Conditioning Information Forum

Just wanted to give you all a little update. I have switched gears to work on an AC project in my 1988 BMW. My wife needs a car with working AC, so I've been focusing on that car. Plus, I've had family in town the past couple weeks, so my attention has been divided. I will be able to get back to the van soon... and will post updates in here!

I don't want you all to think I have given up or abandoned this post.

GottaBeCold88 wrote: ↑Wed Aug 10, 2022 7:10 am Just wanted to give you all a little update. I have switched gears to work on an AC project in my 1988 BMW.

Start a new topic on the BMW if you like.

We wondered how you were doing

Wife's car definitely needs to be the priority, the "yes dear" relationship model is widely successful

this guy is tenacious. I figured he would be back.

Best of luck with the BMW, and start a thread for it if you need help.

Well, the good news is the BMW project was pretty uneventful! So no new thread needed. I don't want to go off on a tangent, but I replaced all the stock stuff from 1988 with a parallel-flow condenser, high performance SPAL fan, a custom bracket to fit a brand new Sanden compressor (SD7H15), new drier, new expansion valve, and new custom hose crimped by me. I replaced all the lines except two that were in the interior under the dash — didn't want to mess with removing them. Then I pulled out the evaporator, and flushed everything old out with a pneumatic flush canister and a few jugs of AC flush. Filled it with 28ox of r134a and she blows in the high 30's, with recirc on, everything full blast, windows open, 1500 rpm, etc.

So I'm glad to have at least ONE AC build under my belt that actually turned out okay! This gives me more confidence as I head back into the van.

Okay guys, with the BMW done I'm looking to get back into the Dodge Van project.

Last we left off, I was going to add an inline service port so I could see pressures right at the overhead evap unit.

Unfortunately, the inline port I bought doesn't fit with the windshield being where it is—it's a bit cramped so I need to get a bit more creative. I ordered some more parts and I should be good to go in a few days.

While I wait for this stuff to add a port by the evap, I have some questions:

• While I have the system empty of r134a, should I also adjust the TXV back to its stock setting? Detroit mentioned perhaps it is flooding at this point.

• Also, when doing the BMW AC build, I learned some stuff. Namely, draining the compressor properly. If you recall, when I did a "reset" and drained and refilled the compressor, I mentioned only less than 1oz came out. My method was flawed I think. I was turning over the compressor by hand, and letting the oil come out of the S and D ports. After only 1oz dribbled out, I added in 4.5 oz of PAG oil. When i did the BMW compressor I surprised to see a similarly small amount of oil come—this was a brand new compressor supposedly filled with oil. Then i discovered there was a drain plug. Wow! Once I opened the plug, a huge amount of il came out. Which makes me think that on the Dodge Van, I didn't properly drain the compressor, and just added 4.5oz to the compressor when it was likely already full of oil because I didn't drain it properly. So, I'm wondering, is there a chance that there is just way too much oil in my system? And if so, what's my action here?

Thanks for your patience, guys.

Detroit has worked with you the most on this, so I'll leave final comments to him.

As far as oil, you def want to try to establish the correct charge. I would indeed drain the comp any/every way you can. Too much oil will def. impair cooling.
As far as the TXV, as I have been following along, I am not so sure I would dial it back to what it was. You are planning to change out the suction line to #12, right? This actually came up quite early in the saga.

Is that a postal scale you are using in the BMW pics? If not, what type. We have posters on here all the time wishing they could do a better job of weighing, but not wanting to invest in an honest-to-goodness refrigerant scale, even tho the prices have come way down.
In any even, how well does your weighing process work?
I can see the small can not moving around much when it is full, but as it gets lighter, doesn't that can have a tendency to flop all over the place?

Yes, I would adjust the TXV back to original setting.

I think your Denso is a fixed displacement wobble plate, the castings look like it, and the Sanden it is trying to be like is also a wobble. There is a separate crankcase that the wobble mechanism is in, my feeling is it should be openly connected to the suction port. If there is a separate plug with soft metal crush washer you could try draining all oil and starting over, but it's a big job.

Thanks guys.

Okay, I will adjust the TXV back to original setting while I plumb in the additional service port. Parts should arrive today.

And sounds like I won't worry about the oil for now. A bit odd that only less than 1 oz came outwhen I did the original drain, but i'll to forget about it for now. I could drain the compressor, but if I do have too much oil, it's likely also in all the lines, etc, so I'd have to flush the lines out. Cross that bridge later. I have plenty of r134a and can keep charging and recovering as we see fit.

I'm prepared to do a #12 hose, after we confirm it would really help, by getting more accurate superheat and subcool readings using my relocated service port.

As for the scale, yes it's a little postage scale I bought on Amazon. Works nice. Yes, the canisters move as the empty out, but if you put them in a little bucket of warm water, and tare the scale to that, it negates the moving problem. And if you go without the bucket of water, as shown in the pic, you can drape the yellow hose in such a way that the weight of the hose keeps the emptying canister from moving around.