Leaky Tilt/Trim Reservoir on '87 Alpha One Mercruiser

[alumanut]

I just recently purchased this boat and, although a long-time boater, I'm new to stern drives. The reservoir appeared to be very low on the tilt/trim pump. Dry runs have not shown any problems in raising or lowering the drive so I simply added the prescribed 10W30/40 oil. I cycled the drive fully up and then back down and left it lowered. A day or so later while vacuuming out the area around the pump I found that the pump and reservoir we're sitting in a pool of oil -soaked carpeting. I had noted the level of the oil in the reservoir after completing the prior add and it had now dropped a good 3/4" to 1". Obviously there is a leak at the pump, but because it went down (---overnight) when the pump was not operating and the drive was fully lowered, my immediate thought is that I have a leaking reservoir. It's raining today and the boat is not covered so I'm playing mechanic via computer. If it does turn out to be the reservoir, will a replacement reservoir fit up with OEM equipment? This is a 1987 Chris Craft with only 350 hours on the engine, so my thinking is that it's all original. Are there other possibilities that I'm overlooking?

 

[Bondo]

Re: Leaky Tilt/Trim Reservoir on '87 Alpha One Mercruiser

Ayuh,... Welcome Aboard,... Donno which pump you've got,... Post a picture of it, there's 3 or 4 different 1s,...

 

[alumanut]

Re: Leaky Tilt/Trim Reservoir on '87 Alpha One Mercruiser

Ayuh,... Welcome Aboard,... Donno which pump you've got,... Post a picture of it, there's 3 or 4 different 1s,...

I'll try to do that when the rain stops. The only other data I can offer, aside from the pump being floor-mounted is that the engine is a 3.0 liter. It's going to take a whole roll of paper towels to clean up the spill. Fortunately, or unfortunately, the carpet around the pump seems to have absorbed most of the oil before it entered the bilge.

 

[tpenfield]

Re: Leaky Tilt/Trim Reservoir on '87 Alpha One Mercruiser

It sounds like you have done the right things to isolate the issue to the reservoir. Definitely need to know which style pump it is to order the right reservoir as Bond-o stated. And hold on to your hat while ordering a replacement, because the price of the thing might blow it away.

 

[alumanut]

Re: Leaky Tilt/Trim Reservoir on '87 Alpha One Mercruiser

Try as I might, I can't figure out how to add photos to the thread! The only new info I have is that the reservoir is definitely cracked - and there is a tag on the pump motor that reads "SAE J1171 - MARINE." Does this serve to properly identify the unit??? Where can I get the correct replacement reservoir? One other tidbit of info is that another label calls for 10W30 or 10W40 oil. Thanks in advance for any help.

 

[tpenfield]

Re: Leaky Tilt/Trim Reservoir on '87 Alpha One Mercruiser

SAE J1171 is the compliance standard for marine use. It basically states that the component is spark protected . Many electrical components in the bilge will have the same tag . . . starter, alternator, trim pumps, etc.

You will have to do some searching on Mercruiserparts.com or Perfprotech.com or elsewhere to verify the correct pump that you have and then can get the correct reservoir

 

[alumanut]

Re: Leaky Tilt/Trim Reservoir on '87 Alpha One Mercruiser

SAE J1171 is the compliance standard for marine use. It basically states that the component is spark protected . Many electrical components in the bilge will have the same tag . . . starter, alternator, trim pumps, etc.

You will have to do some searching on Mercruiserparts.com or Perfprotech.com or elsewhere to verify the correct pump that you have and then can get the correct reservoir

Wow! You learn something new every day! I think I've got it covered if the pump is original (OEM reservoir on order---) which, I'm fairly certain, it is. Otherwise, the search will resume. I stuffed the area around the pump with paper towels so that I can deal with it after Father's Day. My best to all the Fathers out there - young and old!

 

[achris]

Re: Leaky Tilt/Trim Reservoir on '87 Alpha One Mercruiser

Try as I might, I can't figure out how to add photos to the thread! The only new info I have is that the reservoir is definitely cracked - and there is a tag on the pump motor that reads "SAE J1171 - MARINE." Does this serve to properly identify the unit??? Where can I get the correct replacement reservoir? One other tidbit of info is that another label calls for 10W30 or 10W40 oil. Thanks in advance for any help.

How to Post Pictures - The Basics

 

[Don S]

Re: Leaky Tilt/Trim Reservoir on '87 Alpha One Mercruiser

Which pump do you have, A,B or C?

 

[alumanut]

Re: Leaky Tilt/Trim Reservoir on '87 Alpha One Mercruiser

Which pump do you have, A,B or C?

View attachment 198569

Definitely "A."

 

[tpenfield]

Re: Leaky Tilt/Trim Reservoir on '87 Alpha One Mercruiser

Isn't the going price about $50-60 for the reservoir ??? Kind of takes your breath away . . .

 

[ktbarrentine]

Re: Leaky Tilt/Trim Reservoir on '87 Alpha One Mercruiser

You sound like you have the exact same problem with your reservoir that I had when I bought my 1990 Chap two years ago... The reservoir has a screw in the center of the bottom that holds it to the base of the pump assembly. The screw hole develops spider cracks and there is nothing you can do short of replacing the reservoir. Not a difficult job, just involves taking the whole assembly out of the boat. When I went to order the reservoir, found numerous places saying it is obsolete and not carried. I finally found one. I will try and dig up that order info if you need it (edit....re-read your post.. sounds like you have that covered).
After I put the new one in, I placed an inexpensive "glad" type sandwich container under the reservoir, so if/when it leaks again, at lease the carpet wont get soaked, and it makes it easy to check for each outing.
(yes...I remember 50+ for the part...but hey, it's a "boat"!)

First Choice Marine: Sierra Tilt/Trim Reservoir #18-6771 : $50.48

(edit...man, did I get ripped! Its now on Amazon for 28.95!!!!! Look up # 18-6771)

 

[Don S]

Re: Leaky Tilt/Trim Reservoir on '87 Alpha One Mercruiser

Why don't you try replacing the oring between the pump and the reservoir first. PN 25-89498

 

[ktbarrentine]

Re: Leaky Tilt/Trim Reservoir on '87 Alpha One Mercruiser

Agree....Checking the O-ring (and replacing) would be easy and quick (the o-ring on the attachment screw).... But based on the age of the reservoir (older than mine), I suspect it has the typical spider cracks. That will be obvious on disassembly.

 

[Don S]

Re: Leaky Tilt/Trim Reservoir on '87 Alpha One Mercruiser

The newer pumps have a different kind of reservoir attachment than the single screw from the bottom up. 4 screws go from the pump down into inserts in the reservoir. They don't leak near as much.

 

[alumanut]

Re: Leaky Tilt/Trim Reservoir on '87 Alpha One Mercruiser

I sure like the idea of putting a "sump pan" under the pump assembly! I'm away from home for Father's Day so I won't know know until later in the week if I have the correct reservoir. As for simply replacing the "O-ring," I can actually see a crack in the sidewall of the reservoir. I wish that I had seen it before I topped off the oil!

All of the comments are certainly appreciated!

 

[Bondo]

Re: Leaky Tilt/Trim Reservoir on '87 Alpha One Mercruiser

I sure like the idea of putting a "sump pan" under the pump assembly! I'm away from home for Father's Day so I won't know know until later in the week if I have the correct reservoir. As for simply replacing the "O-ring," I can actually see a crack in the sidewall of the reservoir. I wish that I had seen it before I topped off the oil!

All of the comments are certainly appreciated!

Ayuh,... Welcome Aboard,.... Obviously, ya need a New sump,...

All that's to be determined is Which 1,....

 

[alumanut]

Re: Leaky Tilt/Trim Reservoir on '87 Alpha One Mercruiser

This was apparently the original tilt/trim pump, or a copy thereof, because the reservoir for an '87 unit was the right one. I had two surprises: the first was when I released the hydraulic lines (---with the drive all the way down) I got covered in at least a half quart of oil from one of the lines. It just kept squirting and dripping! My analysis of that is that the pump had forced air into the lines, due to the empty reservoir, and then compressed it. My second surprise (---and a caution to others) was that the screw furnished with the new reservoir was too long and it bottomed-out before tightening the reservoir against the O-ring. Since there is a design restriction (---tube) to keep the screw from being over-tightened against the plastic reservoir this problem isn't readily apparent. I exchanged the new screw for the old one and all was well. I cycled the drive at least a half-dozen times full up to full down to get rid of the air, using the trailering switch and topping off the reservoir as needed. It's working well and it sounds relatively good for a 25-year-old pump. There was a lot of congealed grey colored slime in the bottom of the old reservoir. I'm assuming that this was from minor water intrusion over the years - i.e. condensation and the like. The old reservoir was cracked in four different directions. I couldn't figure out how it was holding enough oil to make the system work until I noticed that the oil level didn't seem to fluctuate when I cycled the unit up and down. I concluded, with my limited knowledge of how the hydraulics work, that the oil is simply circulated from one side to the other of the cylinder pistons - i.e. - positive pressure in either direction. For some stupid reason I had simply thought before that oil was pumped into the cylinder to raise the sterndrive and then returned to the reservoir when the sterndrive was lowered. OK - time for all you mechanics to laugh!!!