Has anybody here used foam pipe insulation to wrap the cool line inside their engine compartment?
I stumbled on the idea here:
There are cars made today that have sight glasses on the receiver drier?
Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my address with the letter 'x')
Does that apply to R-134a systems?
Insulating the fat line will help some since heat absorbed on the return trip to the compressor puts an added heat load on the system. Insulating the skinny line may also help if that line is cooler than the environment under the hood. Not sure if it is, but liquid lines running through hot attics are sometimes insulated for this reason.
What would help more is cleaing the condenser and evaporator coils. The condenser coils are next to the radiator and can be gently backflushed with a hose. The evaporator coils are under the dash and are harder to access, but can also be cleaned if you can reach them.
Yup, most, if not all, Toyotas.
Yes.
I think liquid lines running through hot attics are insulated so that moisture does not condense on them and wet the attic insulation and corrode the lines.
Huh! I did not know that. Maybe MBA's aren't running the company.
Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my address with the letter 'x')
Does it also apply to R-12-to-R-134a conversions, where the R-134a charge is 25% less than the recommended R-12 charge? I did what a thought was a proper converson (new compressor, hoses, receiver-dryer, and condenser, flushed evaporator), and the pressures and temps looked right, but the sight glass was foamy at all RPMs and ambient temps. The conversion still worked fine when I sold the car 5 years later.
A few years ago, Ford Motor Company thought it would be a good idea to wrap the AC accumulator on Explorers with foam insulation. Not good... The trapped moisture caused the accumulators to rust out.
Have you seen any problems caused by the GM foam rubber sleeve they fit around most of their accumulators? I have not. Perhaps the Ford design created a complete seal of the unit, while the GM style is slightly open at the top and has a hole in the bottom to shed condensation.
Toyota MDT in MO
GM typically uses aluminum accumulators, the Ford ones were steel.
I still caution because the connecting parts may be steel and they're a bear enough in some climates.
Where ya been hiding?
Got a bit of your weather up here... :-( floods, lakes draining empty, death and destruction. More rain this afternoon.
Sorry, I figured the failure was from oxidation / eventual pinholes. Guess I shoulda processed your phrase "rust out" more literally. I've never noticed a steel accumulator on anything. Doesn't mean the eyes didn't see it though... What asshead would spec a steel accumulator in the pre-high priced aluminum era? Oh, that's right, Ford. It was probably a two for one deal; increase vehicle weight (up high in the engine compartment, no less) and make a normally bulletproof part fail. Suck is job # 1.
20 week 'So You Think You Can Dance' shut in marathon. Whenever there's any down time we watch 'Fame' reruns and eat Haagen Dazs. Actually I've just been busy with the house repairs and work. How's business?Yeah, sorry about the senseless destruction. If you follow our pattern to a tee, expect summer to happen sometime in September.
Toyota MDT in MO
Toyota's chairman emeritus has a PHD.
I don't have any first hand experience with R-12 to R-34-a conversions, but there should not be any foam in the sight glass regardless of the refrigerant. The foam is caused by air in the system. If there is air in the system, it probably wasn't evacuated properly prior to charging.
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Maybe we have different interpretation of 'foam', but when the sight glass shows "air" then you are seeing a lack of refrigerant and oil. It could simply be a void; it doesn't have to be air from improper evacuation.
Typically on R134a systems and conversions with a sight glass, you will see no bubbles at all once the correct charge is installed. {While charging}, the point at which they go away is usually still an undercharged state. Conversely, with OE R12 systems, depending on the heat transfer and localizations within the condenser region, it is generally accepted to see small bubbles during operation. I find this particularly true of FWD electric cooling fan designs especially while high speed fan operation is commanded on, and for a time after the compressor cycles on.
Toyota MDT in MO
With residential systems, the liquid line is rarely insulated. But the suction lines always will be. The suction line is the one that sweats. In a normal system, the liquid line should feel "neutral" and about at ambient temp. If it feels hot, might need to clean the condenser coils outside..
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