Automotive Air Conditioning Information Forum

You are correct, my bad, but since he is having a performance issue, dams for the cond. will not hurt.
Honda's are known for poor AC design engineering, so sometimes we have to takeover ourselves
My nephew is a technician at a dealership and actually is a one-man restoration department, and thus works on a wide variety of makes for every complaint imaginable, including fixing up bad engineering and bad installs by others. Once a car came in with complaint of poor cooling, well what do you know the FD was mounted on its side. He can attest to the less than desirable Honda engineering on several fronts

This has been a long thread, did the issue of re-heating ever come up

tbirdtbird wrote: ↑Sun Jul 18, 2021 7:29 am This has been a long thread, did the issue of re-heating ever come up

What is re-heating?

It depends on how the heater/AC air box is setup. Newer cars have diverter/blend doors to direct either hot air or cold air or a mix, older cars have a hot water heater valve that is shut off when you don't want any heat such as in the summer.
Either system can fail thus allowing warm/hot air to mix with the cold air.

tbirdtbird wrote: ↑Sun Jul 18, 2021 7:29 am You are correct, my bad, but since he is having a performance issue, dams for the cond. will not hurt.

Sorry, tbirdtbird...I didn't make my previous post and its recipient clear. It was intended for the OP and not you specifically. But I agree that adding air dams and seals won't hurt and probably would help regardless of whether the factory put them there or not.

Harry Seaward wrote: ↑Sun Jul 18, 2021 6:47 am JohnHere wrote: ↑Sun Jul 18, 2021 12:33 am
The factory data that I have for your 2007 CR-V specify 18 ounces of R-134a and 4.5 ounces of PAG-46. You mentioned earlier that you charged it with 16 ounces of R-134a and approximately 6.5 ounces of PAG, maybe more. If the specs I have are accurate, it's undercharged by two ounces, and it still has too much oil in it.

I'm looking at the Honda shop manual and sticker under the hood.
https://drive.google.com/file/d/12t-KdO ... sp=sharing
The sticker under the hood says 15.5-17.9 for 134a. I went 16 since that fit nicely within both ranges.

For the oil, I have 3 lines and hoses, unless you count unions; in which case I have 4. 3 + 1.667 + 1.334 + (.334 * 3) = 7(.003)

I believe that the Shop Manual led you astray, and I also think that you're over-complicating this.

You should know that Honda is notorious for being very vague and confusing about listing A/C specifications in their service manuals, not only for your vehicle but also for most other Honda cars and trucks. The chart you reference under "Refrigerant oil, Capacity of components," indicates what each component CAN contain, not necessarily what they SHOULD contain and whose quantities are subsequently added together to arrive at the "total amount."

I have several specification sheets that indicate a TOTAL MAXIMUM of 4.5 fluid ounces of PAG-46 for your vehicle. I believe they are accurate given how small your system is and how little refrigerant it holds. So IMHO, if it actually takes 4.5 ounces and you put in maybe 7 ounces, you have more than a 60-percent excess oil charge in the system--a HUGE overage for such a small system--which, as you're seeing, raises pressures through the roof and results in inadequate cooling.

I would have put 2 ounces in the compressor, 1-ounce each in the condenser and evaporator, and 1/2-ounce in the R/D to arrive at the correct amount.

As for the refrigerant, if you charged 16 ounces net weight and didn't draw back into the system the refrigerant that remained in the Manifold Gauge Set (MGS) hoses, then you undercharged it by roughly that amount. (I described that procedure in another recent post.) On the other hand, had you charged it to the maximum amount of 17.9 ounces per the under-hood sticker (or 18 ounces as suggested), the total charge would still be within the range called for by the under-hood sticker even if you didn't draw back-in the refrigerant remaining in the MGS hoses.

So I stand by my original comment: The system is undercharged and has too much oil in it.

JohnHere wrote: ↑Mon Jul 19, 2021 9:11 am So I stand by my original comment: The system is undercharged and has too much oil in it.

I'm not arguing with you - just clarifying where I came up with my figures, and that I wasn't just winging it. Had I seen the 4.5 before I put everything together, I would have gone that route instead.

No arguments on here. It's just my humble opinion for your consideration to help in figuring out what might be causing the problem

JohnHere wrote: ↑Mon Jul 19, 2021 4:21 pm No arguments on here. It's just my humble opinion for your consideration to help in figuring out what might be causing the problem

It's appreciated! I wouldn't keep coming back if I wasn't interested in what all of you have to say. I just wish (accurately) getting oil out of this system was easier. The lines and TXV on the evap are relatively easy to get at, and I could ~probably~ flush 1.5 ounces out of there. Two rounds of that would ~probably~ get me pretty close to where I should be, but a seized compressor is what brought me here in the first place, and I'd pull what's left of my hair out if I seized another compressor by pulling too much oil out. Next time I have a couple hours with the car again, I'll pull the compressor and do it right. I'm getting pretty fast at getting the compressor in and out.

Personally, I would simply try to just blow compressed air thru and see how much oil comes out, you may not need to flush.

We also paint cars here in our paint booth, so we have a refrigerated air line drier right after the air compressor and our air supply is very dry as a result. But in any case you have been blowing compressed air thru regardless, just be sure to give a good vacuum. Maybe change the drier again

tbirdtbird wrote: ↑Sun Jul 18, 2021 7:12 am " There's just a ~1" gap between the two and it's wide open on the top and sides"
WOW!!
That is the equivalent of an AC mile.
I would get some foam strips in there and you will see a big difference.
I was about to ask you to use a garden hose and mist down the condenser but this huge gap is def part of your problem
Foam=cheap and easy

When we do custom installs we always mount the cond. no further away than 3/8 inch

I have never seen a factory install with that much of a gap.

I agree that 1" gap on the top and sides is not really helpful. It's really a financial decision by the OEM, if an unsealed condenser meets the performance targets, ship it! If it doesn't meet, now you need to get into how much it costs to meet the targets, maybe seals will cost $10, maybe a bigger condenser will cost $3, maybe moving the existing condenser closer to the radiator will be no material cost, but design change cost. $10 added cost means millions of dollars cost to the OEM, it's a big deal.

Condensers are usually mounted close to the radiator, because why not? Underhood package space is really valuable, just ask our cheerful fellow who had to work on a Mazda 6, a little bit more room is luxurious. There isn't much downside to mounting it close until you get really close and the two might chafe if the condenser has already been bent in by hitting a bird but still working. If the Honda has it mounted 1" away from the radiator, there might be some really easy ways to seal up those edges and increase the airflow through the condenser, overall airflow through the radiator will be reduced (has to be reduced, restriction has been added). If you aren't towing trailers up Death Valley grades, I would prioritize AC performance.

Blocking off fins/tubes of the condenser with cobbled seals is probably counter productive, like you gain airflow but lose finned heat transfer area. Best solutions are flat structures that block off gaps, don't need 100% sealing, but also don't block fins.

DetroitAC wrote: ↑Tue Jul 20, 2021 7:45 am If the Honda has it mounted 1" away from the radiator, there might be some really easy ways to seal up those edges and increase the airflow through the condenser

I was thinking of getting one of the black foam tubes (sorta like a small pool noodle) from home depot that people use on their external copper pipes on their house to keep them from freezing. It seems like that should wrap nicely around the sides and top. Not sure how much of the fins would get covered, but it's worth a shot.