Gascolators

Discussion in 'Maintenance Bay' started by Tom-D, Sep 14, 2018.

  1. Tom-D

    Tom-D Taxi to Parking

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    Started new thread because Yes it was major thread creep on the forum.

    This is why I inspect the gascolator on every annual.
    The pictures below are of a Gascolator I removed from a 150, I don't believe it had ever been off prior to this. You'll see the corrosion that occurs in these fuel strainers, you can see the brass 100 mesh screen, which is supposed to separate the water from the fuel, From the looks of it it has never been cleaned or serviced. The "O" ring is hard and brittle, and the whole assembly is dirty, corroded.
    Those that believe these do not require inspecting just because they have no AD, are the inspectors you do not want doing your annual.
     

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  2. timwinters

    timwinters Touchdown! Greaser! PoA Supporter

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    From the 100 hr / annual inspection checklist in my 182's service manual:

    2-15

    Fuel System
    1. Fuel strainer for internal cleanliness, security, leaks, and safetying; drain valve and control for proper rigging, operation, leaks, and security.
     
  3. Dan Thomas

    Dan Thomas En-Route

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    That O-ring came off in one piece? Can't be more than 20 or 30 years old;) I sometimes see them crumble into little bits when they come off.

    I think a lot of airplanes get maintained like cars. Fix it when it quits. That's usually when the fuel filter on a car gets replaced.
     
  4. Tom-D

    Tom-D Taxi to Parking

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    It's pretty evident that some inspectors don't use that as the required list as mentioned in FAR 43-D.
     
  5. kyleb

    kyleb En-Route

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    I replaced the gasket on mine at the last condition inspection. When I pulled the gascolator to clean/check the screen, I found that the gasket had turned brittle - it actually cracked when I flexed it. So I flexed it again. And a new crack formed. Another $3.50 down the tubes. ;-)
     
  6. Dan Thomas

    Dan Thomas En-Route

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    That's a really old gasket. The screen gasket usually lasts quite a while. It's the two O-rings that should be replaced periodically: The MS29513-111 at the bottom, and the MS29513-138 at the top, in the groove where the top of the bowl goes. Then there's the MS29513-010 inside the top body, to seal the plunger shaft. That one is plenty of fun to replace, especially in a crowded compartment.

    The above applies to the typical legacy Cessna strainer. There are numerous other types. When strainers get too old and worn out, repairs can be expensive. Steve's Aircraft has STC'd gascolators that are easier to work with: https://www.stevesaircraft.com/gascolator.php
     
  7. Tom-D

    Tom-D Taxi to Parking

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  8. Dan Thomas

    Dan Thomas En-Route

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    O-rings aren't the issue. Rotted-out bowls, failed plunger tips, standpipes chewed up by mechanics using vise grips, or their valve seats corroded and leaking, screens falling apart: those are the issues. Even the aftermarket parts aren't cheap. The Steve's gascolator uses a single reusable O-ring (metric, mind you, so order spares), a simple screen disc, and you install your own curtis drain valve in the bottom. Cheap to maintain and real easy to open and clean.
     
    Last edited: Sep 15, 2018
  9. Dan Thomas

    Dan Thomas En-Route

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  10. flyingron

    flyingron Touchdown! Greaser!

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    Yep, especially if you find the pilot has been illegally running some amount of unknown autogas in the thing. We've found some Navion crashes that we're pretty sure were caused by ethanol. There are no STCs for autofuel in the NAVION and there are no STCs that permit any amount of ethanol in the autofuel they allow.
     
  11. Tom-D

    Tom-D Taxi to Parking

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    They are the only issue when you do the inspection and find a good unit.
    If you don't find a good unit, 99% of owners will call salvage and get another.
    I don't believe I would advise any owner to buy a $300 replacement when a used good unit is $100 or less.
     
  12. Let'sgoflying!

    Let'sgoflying! Touchdown! Greaser!

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    does this gascolator look ok? 3FB5B36A-816C-4BD9-A8F2-14BBFDB23E98.jpeg
     
  13. Tom-D

    Tom-D Taxi to Parking

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  14. Let'sgoflying!

    Let'sgoflying! Touchdown! Greaser!

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    Looking into it today, will fix up.
     
  15. kyleb

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    My gascolator has one gasket and an o-ring in the drain. The assembly is inspected every year and parts are replaced as necessary. It is a 10 minute job, including the leak check afterwards.
     
  16. Salty

    Salty En-Route

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    This is of extreme importance, but a chunk of broken metal inside the engine is no big deal? Ok.
     
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  17. JAWS

    JAWS Line Up and Wait

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    They are both serious.

    You have to wade through the BS and diatribes to find any value. Welcome to the internet - take everything with a large grain of salt and do your own homework to make your own decision.
     
  18. Let'sgoflying!

    Let'sgoflying! Touchdown! Greaser!

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    Wrong thread?
     
  19. Salty

    Salty En-Route

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    Not me. You?
     
  20. Let'sgoflying!

    Let'sgoflying! Touchdown! Greaser!

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    Oh, I thought perhaps you thought you were in this thread about the metal part in the engine; if not ignore.
     
  21. JAWS

    JAWS Line Up and Wait

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    Welcome to cheap and fast annuals. Complacency at its finest!
     
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  22. Salty

    Salty En-Route

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    No. I was comparing the two threads. Perhaps reread my post?
     
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  23. Gary Austin

    Gary Austin Pre-Flight

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  24. Sundance

    Sundance Filing Flight Plan

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    Of all the years I’ve been wrenching I check mine every 25 hours, yep I know overkill. Usually not an issue it’s clean,but I have cleaned corrosion, If you catch it early and keep it clean it’s not an issue. Not mentioned,I call it the last chance filter on the Carb, I am talking about small Continentals. If I don’t find FOD in the strainer, if I do,I also pull it, usually find hair,little black pieces, bought a tagged carb,fresh overhaul, no filter in it at all. Looks like a sewing thimble. I worked at a flight school for 8 years, every 100 hrs we pulled the gascolator, and the last chance filter. We had 16 Cessna 150s averaged 8 100hr insp every month. Oh the good old days.
     
  25. NordicDave

    NordicDave Line Up and Wait

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    Very common to see gascolator in the above condition when a plane has been sitting. It's the lowest point in the fuel system, as evidenced by the corrosion from water.

    I agree with the above post, this piece is frequently overlooked on annuals. So much for the many log books that say "annual inspection done in accordance with Cessna Maintenance Manual".

    It's a shame since like others have said, the annual required maintenance parts for the gascolator are inexpensive.
     
    Last edited: Oct 9, 2018
  26. wilkersk

    wilkersk Cleared for Takeoff

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    Recently read a story about a guy who bought a super cub from down in Oregon. He flew it back to Fairbanks and had to make and off airport landing for an “engine problem”.

    Turns out the previous owner had apparently been filtering his gas through a chamois. But, must’ve been placing the chamois rough side down over the aircraft filler neck. The gascolator was full of fibers from the chamois. New owner said it looked like the gascolator had never been inspect.
     
  27. Timbeck2

    Timbeck2 Final Approach

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    Other than what appears to be a backwards safety, what else is wrong with it?
     
  28. Plano Pilot

    Plano Pilot Pre-takeoff checklist

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    It was the end of an oil ring that had broken off and came through one of the holes in the oil ring groove of the piston. It must have just happened because the owner said it did use a little extra oil on their last leg.

    I would have posted the results on the other thread but some people could not get along and got it locked. That stopped any additional productive inputs that anyone might have had.
     
  29. JAWS

    JAWS Line Up and Wait

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    That is nice to hear that it was confirmed that it is minor in nature (relatively).
     
    Last edited: Oct 9, 2018