The majority function just fine with up to a 9% pressure leak = they will not hold vacuum.

This is part of why they are so durable.

Perfection is achievable in a lab, but the old German engineers designed the ALDA for the real world.

Thats a little different, I see what you're saying. I simply meant you could create a vacuum signal or suck on the tube and feel vacuum.

Holding vacuum over a period of time, I have never had a reason to inspect.

It is still a reasonable test to apply vacuum to the ALDA to see if it holds even momentarily with a slow leak. Since any ALDA that cannot even register vacuum is surely garbage.

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Any ALDA leaking 1.5% of air pressure will fail to hold vacuum for any perceptible time, when tested with a hand vacuum pump by the average person.

The same ALDA should continue to function 98.5% efficient for ten+ years on average.

Now, I am not some recluse that goes around sucking and blowing on ALDAs, but I have tried about a handful.

Usually, I can create a vacuum. I don't hold it for very long, just a quick test to see if its responding.

1.5% is pretty f-in small, if I may say. Percentages of volumetric flow are difficult to understand and measure. If I put a mityvac on an ALDA I will register vacuum and it will leak down at a reasonably fast rate; this does not mean that I am not registering vacuum.

Saying that an ALDA will "fail to hold vacuum for any perceptible time" seems extreme.

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arguing with master mechanic Whunter about anything mechanical seems extreme...

an alda is a large thin brass soldered aneroid device. it's designed to handle pressure and adjust fuel to compensate for the amount of pressure in the atmosphere... applying vacuum as a test can damage it.

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

Arguing? you've got me all wrong. This is a semantics issue.

As far as applying vacuum goes; if you do not apply too much, there is no issue.

What would you say to the people;e who turn their boost up to 12 or even 15 psi... are they destroying their ALDA?

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possibly, but I doubt they are using an alda with high boost systems...

the destruction I was talking about is atmospheric pressure pushing on an aneroid designed for pressure...
applying EXTREME pressure could also damage it, but I don't know what it's limits are, only that it's DESIGNED for pressure, not vacuum.

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

I definitely agree with you on that.

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..pressure

..vacuum

..blow

Everybody knows ALDA = suck.

Move on.

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Cheers!
Scott McPhee

1987 300D