New member, help with Toyota Hiace AC

[tbirdtbird]

" I had assumed that if the AC is used regularly, it should maintain the refrigerant and not loose charge. Is this not the case? Ie is it abnormal for my Honda to still be working this well at this age?"

Regular usage has no bearing on what is called seasonal losses or attrition. Even barrier hoses will allow a very very minimal leakage. If you want to excel in AC obtain an electronic sniffer. Be certain your plastic port caps are in place, they are actually the final seal, not the schraders.

If it is working well, leave it alone.

Look carefully at the screen when adding pix, once you have selected the pic, there is one more step needed, it says 'place online' or something similar

[JohnHere]

I also have a UK spec but US built '97 Honda Accord Aerodeck, what you might know as an Accord US Wagon, with the F22B engine and factory AC. The AC has never been serviced, but still works very well even after 25 years. Ive owned it for 14 years and use the AC at least twice a week. The first owner (I'm only the 2nd) used it regularly also, he was a family friend and cared for it diligently. It is a R134a system also. Because of my experience of this and other older Hondas I had assumed that if the AC is used regularly, it should maintain the refrigerant and not loose charge. Is this not the case? Ie is it abnormal for my Honda to still be working this well at this age?

I know the F22B as a gasoline engine. As mentioned above, regular use of the A/C system doesn't materially affect the refrigerant charge or loss thereof. If the system still works well after all those years, consider yourself lucky that you haven't had to service it. Seasonal losses, as mentioned, affect the charge, as does leakage past the compressor shaft seal. The system on your Honda must be unusually tight and leak free.

My experience here also is what made me look at the electrical aspect of the Toyota AC first before checking the gas.
Are Toyota's' systems more prone to leakage?

I don't think so.

Is there a significant range different manufacturers AC configurations, ie does the low refrigerant / pressure threshold differ between manufacturers? Would the Honda still be working because the limits are more generous (if they even exist), with the Toyota limits being less forgiving?

Again, I don't think so. Without getting into too much theory, if two vehicles use one type of refrigerant—in this instance, R-134a—the temperature/pressure relationships will still be the same. Therefore, IMHO, one manufacturer's limits won't differ much (if at all) from those of other manufacturers.

[JohnHere]

Could I please have the relevant extracts of the electrical diagrams that you have? I am yet to find a good online manual for van.

These electrical diagrams for your 2009 Hiace might be helpful:
https://fuses.guru/toyota/toyota-hiace- ... x-diagram/

Or, look into a subscription to Mitchell's, which covers the entire vehicle and is probably more detailed. Don't know whether that's available in the UK, though.