Fuel Sender on a Bladder STC

[Toothdok50]

Just bought an M20C that had fuel bladders installed, and I'm finding that one of the fuel gauges (R tank) are not showing changes during a fuel burn.  Are the original type of fuel senders reused with this STC, or have they've been changed out with something more modern.  Of course any sort of mod is possible, but just wondering if its a common practice to reuse the original fuel sender once bladders are installed.

[takair]

Reuses old probe.  Is it stuck high or low?  

[Bob_Belville]

Until the advent of the CiES we used the same 50 year old senders. If you're going to have to spend money put it toward the modern technology.

If the old sender is hanging up you should check on the possibility that the arm is rubbing on the nut plate that the sender bolts into. The bladders seem to have less clearance.

Sent from my XT1710-02 using Tapatalk

[Toothdok50]

Thanks guys...  One tank is showing F all the time.  One is about 3/4 F and never goes above that.  We keep the bladders full, so I'm not sure if it'll go lower, since we've not done many long treks to burn a quarter tank of fuel.  I'll check if there's any impingement preventing movement of the sender arm.

Now I'm trying to pick up a set of used senders to have them refurbished and I'm a little puzzled about the P/N on the device.  My parts catalog is showing two different part numbers--one for the R tank and one for the L tank.  All the senders I'm finding online for Mooney aircraft don't match the P/N listed.  Any guidance here?

P/N called out in parts catalog are: Right:  5641991 and Left:  5642354   Those online are P/N 610242-003.  Is there a L and R that are distinct from each other?  Is one a Mooney number and the other a manufacturer's P/N?  I'm lost...

[carusoam]

Dok,

Keep both eyes open while you are researching your options...

There are some new style floats with digital (and analog) capability... with tremendous proven accuracy... and improved float arms... generally much higher quality than 50 year old floats...

Look up Cies for fuel level sensors...

Running out of fuel is a common mistake for VFR pilots...  mostly, because they think crappy fuel level sensors are OK to have... MS has had IR pilots run out of fuel as well... One was a reminder to not be cheap, the other was a reminder to know before you go... both were heading out to purchase fuel...

If your fuel level sensors aren’t working, get them OH’d or just go with the new ones...

Your screen name indicates you would prefer to not get caught out with a pair of bad sensors...

If your screen name was financially struggling engineer... I remember those days ... i’d Still get them fixed and working properly... it just isn’t that hard... or expensive... even in a plane with bladders...

Best regards,

-a-

[steingar]

I think my fuel gauges are legal, they do show empty when the  tanks aren't empty.  That said,  I wouldn't rely on them for anything save decoration.  I'll switch them out for modern senders one of these days.  In the mean time, I know my fuel burn and my time.  I am rarely surprised at how much fuel I put in the airplane.  Besides, I was told as a student pilot to go by fuel burn and time, and to never trust an airplane's fuel gauges.

[DXB]

I have the old senders inside bladders. One seems pretty accurate, the other never shows above half full but seems pretty accurate below that level.  I've refused to put any money into fixing these things because I will not ever be able to put trust in them anyway - they merely meet the legal standard.  I do put some trust in my fuel flow, which seems very accurate. 

There's a recent thread in the Modern Mooney section about an Acclaim owner who recently experienced a disparity between tank gauges and fuel flow data, in conjunction with a fuel smell in flight.  The enormous fuel leak he developed under the cowl very fortunately didn't ignite or cause fuel exhaustion. CiES senders are in my near future. Then any major disparity between my fuel flow total and the gauge readings is unlikely and also can then be treated as a serious issue without hesitation if it happens.

[Old Chub]

I have a 68 C model with bladders and CiES sending units.   I had the same issue with one tank (L/H) showing full all the time.  I removed the side panel (after troubleshooting with meter) and found the sending wire loose on the sending unit.  

[Toothdok50]

I'm really trying to get this issue corrected.  I do want fuel senders I can rely on.  Perhaps I'll have to do the CiES senders---what's a thousand bucks amongst friends?  I'm just a little confused about their ability to work with current gauges.  They say they work with resistive gauges, but you need a "tank and gauge map."    What?  That put me off, as I'd like to use those gauges that are currently in the panel.  Any ideas as to what that means?  No A&P here...

 

[carusoam]

Dok,

Got an engine monitor like a JPI900?  Match the Cies gauges and JPI together... frequency based is all the rage.., compared to resistance based... accuracy is everything.  More accuracy is even more preferred...

Don’t have an engine monitor, buy the digital fuel level gauges that match your float’s needs... (Cies has recommendations for that too...)

Do you have a mechanic that can help you with the best way to outfit your plane?

There are many threads around here of people that have been in your shoes already...

You can read them, or have your mechanic do the required research...

There is one thread where a Pro-pilot just claimed he threw out his old mechanical float sensors because nobody wanted them... 

 

Many people have decided that their plane is a forever plane... no matter what it is... it gets top of the line stuff... Engine monitors and WAAS GPS are to protect the pilot... and his wallet... what’s another amu...?

PP thoughts, not a mechanic...

Best regards,

-a-