The International Cessna^® 170 Association

I'm helping a friend with a 1960 172 and an O-300C - it has an STC for an Airborne Mechanisms pulley-driven vacuum pump. The pump is Tango Uniform, the shaft has sheared and the rotor shattered. No overhauler will touch it. Airborne Mechansims seems to be TU also. If someone has a spare or overhaul kit, that might be nice. Any other ideas? (other than a venturi, which I suspect is in his future.)

Russ Farris

Earl Eastabrook (deceased last May) had the info on how to repair that pump legally, and I think I may have his documentation at the house. Today Jamie and I are at Gary and Deana Hanson's celebrating New Year's Eve and I will look up the info when I return home in a couple days.

Everyone....Happy New Year!

Hey George! As usual your'e the first to hit the button with an answer - I appreciate you checking into this. He wants to replace the pump with a venturi, but that's more involved than just fixing the pump, if possible. It's a VFR airplane, anyway.

Happy New Year to everyone! Russ Farris

Hey Russ,
Dad's engine went TU, but the belt driven pump is still alive......Dad can't believe that the pump lasted longer than the engine 35 years and the original pump...IFR aircraft...Don't know what we are doing with the engine....have to see if the crank is salvagable....May be able to send you the whole kit and kaboodle if we change to another engine...

russfarris wrote:Hey George! As usual your'e the first to hit the button with an answer - I appreciate you checking into this. He wants to replace the pump with a venturi, but that's more involved than just fixing the pump, if possible. It's a VFR airplane, anyway.

Happy New Year to everyone! Russ Farris

Re: first to answer:
That's sort of a goofy thing. My personal outlook has been that (as the originator of the forums) I was responsible for addressing participant's messages, so years ago, I got into the habit of making certain that anyone/everyone's posts received prompt replies. (There's nothing more discouraging to a newbie than finally getting up the courage to post a msg and have it go completely ignored.) My secondary impression is as the Parts/MX Advisor, that I'm required to either provide an answer or stimulate the discussion so it leads to solutions.
As an unfortunate result, some folks (especially new-comers) have seen those responses as discouraging participation by others. (I occasionally rec'd nasties from newbies holding me accountable for "hogging" the conversation, which has always puzzled me.) The old-salts realize that's not intended, and either tolerate or downright ignore me.

Re: venturi
If it were my airplane, I'd remove any dry vacuum pump (except a wet one on a "D" engine) and replace it with a venturi. Air Wolf advertises a new style dry pump that they claim is as reliable as the old wet ones, but I've not looked into them and so I'm skeptical. I know that venturi's have never failed me. Some day I expect to come into my inheritance and dream of installing a backup electric horizon. (Standing by for responses on THAT statement.)

russfarris wrote:I'm helping a friend with a 1960 172 and an O-300C - it has an STC for an Airborne Mechanisms pulley-driven vacuum pump. The pump is Tango Uniform, the shaft has sheared and the rotor shattered. No overhauler will touch it. Airborne Mechansims seems to be TU also. If someone has a spare or overhaul kit, that might be nice. Any other ideas? (other than a venturi, which I suspect is in his future.)

Russ Farris

Try these guys.

We can overhaul your core at a cost of $375.00



Victor Harris

Aero Accessories, Inc.

1240 Springwood Avenue

Gibsonville, NC 27249 USA

Tele- 800-822-3200 or 336-449-5054

Fax- 336-449-5461

Also check this thread. If you find some parts I would be interested. There was a guy in Texas that was selling the whole installation started out asking $3500 I had him down to $1750 But the deal didn't feel right with out being able to hold the parts in my hand and look at them, so I passed....... If you find parts I'm still looking for parts at reasonable prices.

http://cessna170.org/forums/viewtopic.php?p=32766

Here are a couple of opinions that come under that IMHO thing. (Actually, none of MY opinions are REALLY humble.)

1. Flying hard instruments in a C-170 is foolish.

2. Trusting a dry vacuum pump is very risky.

3.Anyone flying hard instruments, especially at night, in a C-170 using a dry vacuum pump has a serious death wish.

Here's the outcome of the vacuum pump story. Aero Specialities recieved the pump on Monday, on Thursday I got the phone call it was re-built. Price 350.00. I'm personally a fan of venturis, but this was the easiest plan on my friends 172, he's not instrument rated and never will be. Thanks to everyone for the information. Russ Farris

And to think that some folks get pizzed off and abandon the forums just because someone disagrees with their opinion on something. Good job, Russ and Tim! BluEldr will send a sympathy card when it croaks inflight.

I've just gotten up enough courage to finally post and so I'll say this - Gahorn and Bludr, I totally disagree with you!

AR Dave wrote:I've just gotten up enough courage to finally post and so I'll say this - Gahorn and Bludr, I totally disagree with you!

Dave, I agree with you.....but not totally......my perspective is ...any one flying hard IFR in a single engine, has a death wish......not just behind a given vacuum pump ...Brad

AR Dave wrote:I've just gotten up enough courage to finally post and so I'll say this - Gahorn and Bludr, I totally disagree with you!

HA! (Everyone:.... ARDave has this particular mod on his very nice 170B.) Hey, Dave!...OK if we jes' come up and camp without expecting you to take care of us? Can you actually jes' come out and visit without feeling like you gotta chop wood, cook, and care for our every need? I think a lot of us would be happy just bein' there.

I've been led to believe that Parker/Hannifin got out of the dry vacuum pump business because the FUZZ was going to require them to enclose a generic will form in the papework with each pump.