Port oil line goes where and does it need maintenance changing?

[jimmaki]

I thought I was just doing routine maintenance on my 1998 SPX but it's slowing turning into a full resto part by part. The starboard oil line off the bottom of the oil tank goes to a fitting on the side of the crankcase which is very visible and easy to get to with the carbs out for rebuild. But the tube that goes from the top of the oil tank/breather disappears down the port side of the engine under what I think is the tuned pipe. Is this something can can be changed without taking off the pipe and is it even necessary to change it? I can't see if or where it's rubbing against the hull so I don't know if or how badly it might be chafed but I see no unusual amount of oil in the bilge so I'm pretty sure it isn't leaking. Should I replace the oil line that's on the starboard side? It seems ok ... what's the criteria for changing it? I am planning on changing the oil filter and the 3/32 lines from the oil pump to the check valves on the intake manifold.

[EDIT] I just thought of something related to this. I've been using XPS mineral oil since I had my 1993 XP. But read somewhere that the RAVE engines like the one in my XPS, should be run on synthetic oil. I also read if you change oil to change or clean everything oil related as mixing oil can cause problems. I don't want problems but I also am not looking forward to changing all the oil lines (see above). If I go from XPS mineral to XPS synthetic, am I in trouble if I don't change drain, clean, and otherwise refurb the oil system?

 

[LouDoo]

I think that's the return oil line for the drip feed for the rotary valve, it probably does not need changing.

Lou

 

[jimmaki]

I think that's the return oil line for the drip feed for the rotary valve, it probably does not need changing.

Lou

Great, I wasn't looking forward to having to change it. I've always used XPS mineral oil in it, but I heard the RAVE engines should use synthetic. Can I switch from XPS mineral to XPS synthetic without changing all the oil lines, draining and cleaning the oil tank, priming the lines and filter and pump, etc.

 

[fitty650sx]

Drain the tank, pump feed and the rotary lines as best you can. Change the oil filter after the mineral oil is out. The injection lines will be fine if there is mineral in them. Refill with synthetic and bleed the oil pump as the manual states.

I would check the oil pump calibration at the same time, as well as red-loctite the little screws that hold the cover plate onto the top of the oil pump. Take one out, spray it with brake cleaner, dry, loctite, and reinstall. Repeat with the other one. Of the three 787 engines I've had, all three had loose oil pump screws.