Mercruiser oil reservoir - A Good Maintenance Idea

2003 - 5.7L 350/300HP with Bravo 3 - 1000 hours.

I do my own maintenance. It's been a good experience and I do not think a yard would give 'the love' I do. Sometimes it comes back to bite me in the *ss, but live and learn ( like NOT knowing to torque my gimbal ring to shaft nuts each season - that was an expensive lesson )

So, I was going to fill my outdrive reservoir as I always do at the beginning of the season. It was bone dry 'cause when I drain the lower unit, I let the res oil out too ( I know I could clamp the feeder hose, but...)

I looked in the res and it was goo! I mean sludgy, thick, gonna-create-a-problem - goo.

My Advice - Take a look at the bottom of the res. For me, the oil was not going to flow into the feeder hose that feeds the drive and, potentially, the sender would not rise or lower right either - not letting me know I was low on oil.

The FIX- Remove the reservoir ( do NOT loosen the big nut on the bottom - that would be a PITA to re-tighten - trust me. ) instead, pull the wires where they attach to motor, remove the feeder hose and remove the whole reservoir. I used diesel fuel oil to clean the reservoir, shaking it around and, I used a coat hanger, bent straight with a small pc of rag bent in place with the end of the hanger - to get into the tight places in the bottom of the reservoir. Once clean, remove all diesel, then reinstall the way it came out. Take a pix with your cell to capture the position of it all. Refill and look for the next thing that's gonna be a PITA !

I would also add that you should look at the hose. Over time they get hard, even brittle, and can fail. Result: bilge full of oil. If you can't pinch the hose tight, it's probably time for new.

2004 mag

Posted the same tank condition in 2016. Now, if you can remove a non-leaking oil filter for maintenance w/o cutting it in-half, I'm listening... BT told me to get a strap wrench...got one over the winter....will see how the strap wrench works later this summer...what a poor chevy design

Never have had to cut one. You might be over tightening ? Mine never leaks, and although not easy to remove, with a strap wrench they always come off.

A Trick - when dumping oil for season and removing filter - for a fast, clean change out--- poke a hole in the top of the oil filter with a screwdriver 'jab' - helps to drain the oil out of the filter fast. Wait a few minutes, then, use a ziplock under the filter to capture any oil and the filter.