Javelin aux fuel tank problems

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olypenflyr
Posts: 12
Joined: Fri Sep 28, 2018 5:01 pm

Javelin aux fuel tank problems

Post by olypenflyr »

Purchased this 170B last year. Put fuel in the aux tank and flew to test the system. I can hear the pump working on the ground, but a few problems are present. Fuel gauge and fuel transfer light don’t work. In the air after switching to the left tank with the right tank half full there was no change in fuel quantity after 20 min with the pump on. Returned to the airport and drained out 14 gallons- the amount I had put in. We are due for annual in three months so I plan to get this operational. Would like someone with experience with these tanks to give me a call to help diagnose and possibly where to get parts. I have the STC but no other installation paperwork to help. Cell number is 206-719-7116. Thanks much.
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GAHorn
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Joined: Fri Apr 12, 2002 8:45 pm

Re: Javelin aux fuel tank problems

Post by GAHorn »

Did you check the various documents posted in this thread? http://www.cessna170.org/forums/viewtop ... =41&t=6925
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
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n2582d
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Joined: Mon Apr 29, 2002 4:58 am

Re: Javelin aux fuel tank problems

Post by n2582d »

Dave,
A copy of the Javelin installation instructions was sent to your email address. They are also available here.

Just because you hear the pump turning doesn't mean it is putting out pressure as it's not a constant displacement pump. Here's how Javelin says to check for proper operation:
Click to Enlarge
Click to Enlarge
They say, "The pump rate is 2.5 minutes per gallon. One hour should be allowed to transfer the 18 gallons." Those two flow rates don't add up but does give you an idea of how long it takes to empty the aux. tank -- 45-60 minutes. The first thing I would check is to see if the filter is clogged on the pump. Pegasus sells a 74 micron filter or the courser 400 micron filter and the end gasket. Once that is checked see if you have any fuel pressure with the pump on. Max. pressure for the Bendix 476087 pump is 4.0-5.5 psi. If you have an older pump it has points, what Bendix calls "Interrupter". Current pumps are solid state or "Electronic". Another thing that might be worth checking is the check valve. Any chance it is stuck closed?
Gary
olypenflyr
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Joined: Fri Sep 28, 2018 5:01 pm

Re: Javelin aux fuel tank problems

Post by olypenflyr »

Thanks, I'll check all that and thanks for the instructions. It has an older pump - not the Bendix pump. Since this hasn't been used in number of years maybe it will be as simple as a clogged filter, etc.
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c170b53
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Re: Javelin aux fuel tank problems

Post by c170b53 »

Can you post a pic off the pump ?. It maybe an early model not well identified.
Jim McIntosh..
1953 C170B S/N 25656
02 K1200RS
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n2582d
Posts: 2808
Joined: Mon Apr 29, 2002 4:58 am

Re: Javelin aux fuel tank problems

Post by n2582d »

Bendix line of pumps was taken over by Facet. Here’s the “decoder ring” for finding out what pump you have (assuming it’s a Bendix or Facet pump). I’d consider getting the right pump if you don’t have the paperwork to go along with a pump different than what’s called for by Javelin.
Gary
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n2582d
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Joined: Mon Apr 29, 2002 4:58 am

Re: Javelin aux fuel tank problems

Post by n2582d »

Dave,
Recent discussion on the fuel valve placard got me thinking about paperwork and placards required for the Javelin auxiliary tank. First, you need to have the Javelin supplement to the Airplane Flight Manual (AFM) on board. This is found here. That document directs you to have three placards. Next there is AD 73-17-01. This requires a placard under the transfer switch shown here. There are also some rules in the FAR’s that I’m not completely sure apply as this tank is not installed as an STC as it is listed in the TCDS. To be on the safe side though I plan on complying with them. The first is found in Appendix B to part 43:
(d) For extended-range fuel tanks installed within the passenger compartment or a baggage compartment, the person who performs the work and the person authorized to approve the work by §43.7 shall execute an FAA Form 337 in at least triplicate. A completed copy of that form shall be—

(1) Placed on board the aircraft as specified in §91.417 of this chapter;

(2) Given to the aircraft owner; and

(3) Forwarded to the Federal Aviation Administration, Aircraft Registration Branch, , Post Office Box 25724, Oklahoma City, OK 73125, within 48 hours after the work is inspected.
FAR 91.417 (d) referenced above says:
(d) When a fuel tank is installed within the passenger compartment or a baggage compartment pursuant to part 43 of this chapter, a copy of FAA Form 337 shall be kept on board the modified aircraft by the owner or operator.
Finally, if your aux tank doesn’t work it should be placarded “INOPERATIVE”. :roll:
Gary
jon s blocker
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Joined: Tue Apr 23, 2002 1:56 pm

Re: Javelin aux fuel tank problems

Post by jon s blocker »

Make sure you put the inline check valve in the right direction. If you put it in wrong, (the wrong direction), the fuel will not be allowed to be pumped into the wing tank. Obvious, but easy mistake, don't ask. Jon
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