Holy smoke, that's some fireworks!

What do you use for a vac pump, single or dual stage? What vacuum level do you get it down to? What do you use for a vacuum gauge to see the level achieved?

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85 300D turbo pristine w 157k when purchased 167,870 July 2025
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

Single stage commercial . Have calibrated gauge and at 1100 asl I see 29 inches. If you hold 29 for some time and run the engine to full temperature you can be sure that whatever minute amount of water vapor is in the system is absorbed by the desiccant....or so small a volume it will not ice anywhere..


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[http://languageandgrammar.com/2008/01/14/youve-got-problems-not-issues/ ]

"A liberal is someone who feels they owe a great debt to their fellow man, which debt he proposes to pay off with your money."

Would you know if I run two vacuum pumps in series, would I be able to achieve lower vacuum levels than a single pump? I can rent (free) a single stage pump from Autozone, I can scrounge up a compressor from a house AC unit and run that in series.

I need to come up with some kind of digital vacuum gauge. They seem to start at $140 and up. This one reads in microns https://www.amazon.com/CPS-VG200-Digital-Vacuum-gauge/dp/B009AXGCSC?ie=UTF8&redirect=true&tag=gols-20

I don't care the units used. I can convert them Vacuum Pressure - Units Converter

I am buying one of these to play with, $20 shipped New SMC RS Vacuum Pressure Switch ZSE4B 01 26 Q | eBay

readouts in kPa, mm HG, psi and bar

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85 300D turbo pristine w 157k when purchased 167,870 July 2025
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

[QUOTE=funola;3608741]Would you know if I run two vacuum pumps in series, would I be able to achieve lower vacuum levels than a single pump? .......................................................[UNQUOTE]

I would say no. Both pumps do the same thing so very low vacuum of 1 torr or better would not be attained. Even lab' rated vac' pumps only pull down to 5 torr.

You need very specialized ( read : Expensive.) equipment to pull a near pure vacuum.

I would say that is is impossible to pull a pure vacuum.


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[http://languageandgrammar.com/2008/01/14/youve-got-problems-not-issues/ ]

"A liberal is someone who feels they owe a great debt to their fellow man, which debt he proposes to pay off with your money."

[QUOTE=dkveuro;3608748]I can have access to a vacuum pump used in a lab, problem is getting permission to wheel my car in there. And then explaining of why I need that sort of vacuum in my car A/C

btw - funola

I have lived in third world countries where resources were scarce, I regularly saw A/C work being done by pressure testing with a junked refrigerator compressor pushing air in the system.

It was good enough - cant say about longevity, usually A/Cs were taxed to the max as summer meant 120F in the shade.

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1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)