Looking for a used Pitot Tube

[kevinw]

The pitot heat is tripping the circuit breaker that's built into the switch and I'm told there's something going on internal to the mast or heating element. I'm also told a new pitot tube runs $3,200 so I'm looking for a good used one. If anyone has one laying around or can point me in the right direction please let me know. '82 M20J. Thanks, Kevin

[Bob_Belville]

Alan Fox, Jerry Pressley, and Paul Loewen all deal with salvage Mooney parts.

[takair]

1 hour ago, kevinw said:

The pitot heat is tripping the circuit breaker that's built into the switch and I'm told there's something going on internal to the mast or heating element. I'm also told a new pitot tube runs $3,200 so I'm looking for a good used one. If anyone has one laying around or can point me in the right direction please let me know. '82 M20J. Thanks, Kevin

Be sure it is the pitot tube.  The switches degrade too.  Does it trip instantly or after time?  Check if the switch warms up first, if it does, it may simply be the switch.  Not cheap, but cheaper than the tube.

 

[kevinw]

When I turned it on to test it, it switched off after about 3-4 seconds. What's strange is I removed the four screws that hold the pitot in place, disconnected it and tested it for voltage and continuity. While I know just enough about electrical issues to be dangerous, they both tested normal. After I reconnected it, it worked normally and I thought it was a connection issue but the next time I flew, I turned it on and it switched off in about 3-4 seconds. My mechanic, who hasn't had a chance to look at it yet, told me to start looking for a used pitot but now you have me thinking it might be the switch.

[1964-M20E]

While you are looking for cheaper alternatives look at the wire to the pitot tube.  You may have chafing that shows up as a short when the engine is running.

[Igor_U]

On my '67F, switch is actually Klixon circuit breaker switch that got weak and would do the same. Replacing it with a new one  (same amperage) solved the problem.

I believe your M20J has also Klixon CB, just a different, rocker type then my plane.

Good luck.

 

[kevinw]

Thanks for the responses. I looked the best I could for wire chafing and didn't see any. Sounds like I really need to rule out the switch before buying a pitot as it seems more and more likely this is the real issue. Just need to figure out an easy way to test it.

[Nippernaper]

I just replaced my pitot on my 78 J with a NOS. Ebay is your friend.


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[thinwing]

Not sure of your wiring diagram ,but my M has a relay between  switch and pitot heating element.A week cb /switch ,if no relay would pull about 10 amps ...either way if pitot initially powers up and grows warm ...than I doubt it is pitot tube

[kevinw]

9 minutes ago, thinwing said:

Not sure of your wiring diagram ,but my M has a relay between  switch and pitot heating element.A week cb /switch ,if no relay would pull about 10 amps ...either way if pitot initially powers up and grows warm ...than I doubt it is pitot tube

I'm going to run out to the hanger tonight and see what I have in there. Looks like an E-T-A switch and I'm hoping either the nav light or landing light switch is the same type so I can change them out and confirm this is the issue.

[Igor_U]

Kevin,

please make sure you use same amperage CB switch; I would expect pitot tube heater would draw more amps then nav lights or similar.

it seems you already removed the pitot tube before and tested OK... You could do it again and also remove suspected switch and test it on the bench, if you have few wires lying around to connect to a power source. If all good, it would point to airplane wiring and if it disconnects, it could mean switch getting weak.

[EricJ]

7 hours ago, kevinw said:

The pitot heat is tripping the circuit breaker that's built into the switch and I'm told there's something going on internal to the mast or heating element. I'm also told a new pitot tube runs $3,200 so I'm looking for a good used one. If anyone has one laying around or can point me in the right direction please let me know. '82 M20J. Thanks, Kevin

My airplane failed static check a few months ago due to a leak in the pitot tube.    A new one was less than $700 for my 77 M20J.

[kevinw]

My airplane failed static check a few months ago due to a leak in the pitot tube.    A new one was less than $700 for my 77 M20J.

That’s interesting. $3,200 seemed outrageous. Thanks for sharing that


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[Guest]

11 hours ago, kevinw said:

The pitot heat is tripping the circuit breaker that's built into the switch and I'm told there's something going on internal to the mast or heating element. I'm also told a new pitot tube runs $3,200 so I'm looking for a good used one. If anyone has one laying around or can point me in the right direction please let me know. '82 M20J. Thanks, Kevin

Before spending that kind of money I’d like to be certain.  Why not connect a similar current draw to the wire at the pitot head to test the breaker/switch.  Something like an incandescent landing light bulb should work.

Clarence 

 

[kevinw]

Before spending that kind of money I’d like to be certain.  Why not connect a similar current draw to the wire at the pitot head to test the breaker/switch.  Something like an incandescent landing light bulb should work.
Clarence 
 

That’s a really good idea. I was also thinking of powering the pitot with a 12v battery with a 15A fuse in there to see if the fuse blows. Thanks Clarence, I’ll try your idea first


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[Guest]

8 minutes ago, kevinw said:

That’s a really good idea. I was also thinking of powering the pitot with a 12v battery with a 15A fuse in there to see if the fuse blows. Thanks Clarence, I’ll try your idea first


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Powering the pitot tube would also make sense to isolate the problem.

Clarence

[Yetti]

Hook it up and shake the end of the wing to get some vibration going.

J schmatics http://mooney.free.fr/Manuels M20J/M20J/Mooney Service Manuel M20J Vol. 2 of 2.pdf

 

[Eraaen]

Wow, prices all over the place.  Everything checked out from the dash to the tube.  I was charged $1145.99 to have it "overhauled"  I don't know if that meant it was traded/core charge, or if it was somehow repaired.

[carusoam]

Expect CB switches to mechanically wear and become weak...

things with high loads used all the time like landing lights aren’t a surprise when needing replacement...

The surprise is the cost of the CB Switch... and the challenge to get it swapped out with a long bus bar in the way..,

PP thoughts only..,

-a-

[kevinw]

Well it turns out it's not the switch. The pitot tube was removed and bench tested. It has a short in the heating element. 24V tubes are plentiful but the 12V model not so much. I'm on the hunt for a good used PH502-12 or AN5812-12

[markejackson02]

1 hour ago, kevinw said:

Well it turns out it's not the switch. The pitot tube was removed and bench tested. It has a short in the heating element. 24V tubes are plentiful but the 12V model not so much. I'm on the hunt for a good used PH502-12 or AN5812-12

Alan Fox?

[kevinw]

I found a pitot tube on eBay so should be good. Thanks everyone.