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