Rick
Titsworth wrote:
Put this is the category of you
don’t know what you don’t know… The attached photo
shows two fittings.
The top one (actually two) is from the bottom of a TSIO0550 oil
cooler where it feeds the turbo’s (for cooling) - at least that’s
what was on my engine and seems to reflect the diagram in the TCM manual.
The bottom one is functionally the same thing but is a single fitting that I
got from a local hydraulic fitting supplier.
Is there a reason that TCM used two fittings when they could have
got by with one?
It appears the original(s) might be brass and steel (plated).
I’ll re-check when I’m out at the hanger. The new/bottom one
is steel (plated). Perhaps there is some issue with the steel fitting in
the aluminum oil cooler housing (galvanic/seizing), or perhaps they intend the
brass fitting to be softer when attempting to get it in/out (if it’s
stuck), or ????
Anyone have any insight before I insert the new one? I was
going this way because I desired the shorter fitting for better hose
clearance/alignment.
Also, some time ago, I replaced a 90 degree TCM fitting on the fuel
pump with a 45 degree steel one. Now, I don’t recall if the
original was brass? and/or don’t know if that was a mistake for some
reason. I don’t recall anything in 43.14 regarding brass vs steel
fittings in aluminum housings – but’s there’s plenty of stuff
in there that I may have missed/forgotten.
I’d also be interested in the opinions of others on the
list about this. I found a couple of instances of exactly the same situation on
my TSIO-550, including a couple of 90 degree fuel system fittings where a 45
would make hose alignment and routing better. Thinking the 45 degree fittings
provided a smoother fuel flow path, I substituted where it made sense. I also
swapped out multiple fittings, including the above noted, for a single, and in
one situation used two 45 degree fittings vice one 90 degree to provide
clearance around an engine mount tube. Used good quality steel Parker fittings.
Bob Pastusek