IdahoMooneyPilot

Fly Boomer: Thanks for the direction - will do!

Bartman & Fly Boomer: Thank you both for the IPA info & Amazon lead. I actually have 99% IPA; I will scour my POH for that information, as well as touching base with Griggs (nee O&N) regarding the bladders to see if they are compatible with IPA. And to your point - yes, 70% IPA is 30% water - it won't solubilize much additional water (if any), and might actually drop its water when added to 100LL. I had wondered about doing something like that - it's nice to hear confirmation from others!

EricJ: Wonderful information!! Thank you for sharing it. From what I heard from the servo overhaul shop, the screens are plain steel - and so they rust. I also understand that the boost pump is a vane-type pump with a steel sleeve that the vanes ride on; perhaps with ingress of water (which then sits for a while, depending...) that steel sleeve rusts a bit. I have had one party recommend rebuilding or replacing the boost pump as it may fail (and yes - mine is old too - I think it is an old Dukes, but haven't looked...). Thanks again!!

EricJ: I appreciate your quick feedback, and that you've had direct experience with this issue. Thank you! May I ask about your fuel pumps after your servo problem? Did either fuel pump: 1) have to be cleaned / overhauled / replaced?, 2) have problems or show evidence of trapped water causing damage?, or 3) no problems to date with either of the fuel pumps (no failures or no re-contamination of the fuel injections servo)?

N201MKTurbo: Thanks for your input. I note that after about 25 hours of flight (when the servo started misbehaving badly), on opening, the shop did find water trapped against the diaphragm, which is a low spot in the assembly. The water had not flushed out, but sat in there corroding springs, filters, etc. Fortunately no sealing surfaces had yet been compromised, so the unit is repairable and is being overhauled.

First - a warning: I have an M20J, with O&N bladders from about 20 years ago, with the old Shaw Aero fuel caps. My new (now former) A&P last year decided to do me a "favor" and replaced the O-Rings on my fuel caps. Thing is, he didn't do any research. It turns out that Shaw made about 50 different styles, and the ones I had were exceedingly rare (I doubt they installed 50 of them), with no documentation available today - - so inevitably the A&P put in the wrong O-rings, just as winter was coming on. Three months, parked on a slight slope, and 12 inches of wet snow later, I ended up with about a pint of water in each tank, which successfully hid in the bladders when I (religiously) sumped tanks and gascolator, only finding a trace of water from each at that time. Fifteen minutes later, the engine quit just as I was throttling up for takeoff - and that's when the bulk of the water manifest at the sumps and in the gascolator. This led to water contamination in the fuel injection servo, which I didn't realize was significant until operational problems with the servo this fall, after six months and 25 hours of flight. Fuel servo is now out for overhaul, and was found with water & rust inside upon opening. BTW: The fuel caps were immediately replaced six months ago with Griggs' (nee O&N) new cap & flange assemblies out of England, and they are wonderful! Not a drop of water. Now, my question: Have any of you had experience with this kind of thing? Did you find that the fuel pumps (engine & electric boost) also had water contamination issues, or were they fine? After 25 hours of flight, my gut feel is that any water in the pumps has probably been cleared - but I am not certain, and no two A&P's concur on what corrective action, if any, is needed regarding the pumps. I'm not too worried about from the fuel tanks up to the gascolator, as the gascolator is designed to trap out small amounts of water. I'm confident the fuel tanks & lines are clear of water up to the gascolator. But what about the pumps? Do they trap water the same way as the fuel injection servo?