Replacement Tilt/Trim pump?

DHag

Petty Officer 2nd Class
Joined
May 29, 2007
Messages
166
I have a '79 Mercury V-150 V6. Dual cylinder tilt system, round-motor Prestolite pump mounted inside the boat. Both pump and motor are going out.

I'm finding it next to impossible to find a complete replacement that doesn't cost half what the boat is worth. Most of what I can find is "motor and reservoir only with no valve body." In other words, no pump. Just the motor.

Will this newer "Oildyne" type of pump work as a replacement?
iBoats item here
EBay store item here

It's for 225-275 horse Mercruiser. But just looking at it, other than possibly needing to adapt the hose fittings, I can't see why not. I'll try to contact the manufacturer, but thought I'd ask here, too.
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,033
Re: Replacement Tilt/Trim pump?

I do not think either of those will work for you.

There was an aftermarket "pump and upper resevoir", that would fit. You reuse the lower resevoir cover which has the pump and control valve. However, there are at least two kinds of these. Both will bolt up, however, one has a shorter armature than the other, and it will not drive the pump. I would cross reference them to the parts diagram for your motor, or match them up in person.
 

RRitt

Captain
Joined
Mar 30, 2006
Messages
3,319
Re: Replacement Tilt/Trim pump?

measure the amount of fluid displaced when the rams retract. the volvo AQ290 pump is the "best buy" trim pump by a mile. Its easy to find for under $200 and easily as good (or better) than anything mercury sells for under $1000. In fact, mercury used to sell the exact same pump for about $850. I guess somebody forgot to tell Volvo that boat parts should not be priced the same as car parts. But the reservoir only holds a cup or two of fluid. If your rams displace more fluid than the reservoir holds then you can't use the volvo pump.
 

DHag

Petty Officer 2nd Class
Joined
May 29, 2007
Messages
166
Re: Replacement Tilt/Trim pump?

the volvo AQ290 pump is the "best buy" trim pump by a mile. Its easy to find for under $200 and easily as good (or better) than anything mercury sells for under $1000.
I found an Arco replacement motor and reservoir for $169, which is a third the price of the OEM replacements. That's funny, since the Arco is listed as the "premium" unit by most sales sites.

My pump is still working. Mainly just the motor is dead. A fresh motor spinning at full speed may make it work fine. Also, I'll replace the O-rings and other seals while I'm in there.

I also found a blow-up diagram of the pump itself. It may not be "serviceable" according to the official literature, but it can be taken apart. If it can be taken apart, then it can be refurbished, even if I have to fabricate something.
 

DHag

Petty Officer 2nd Class
Joined
May 29, 2007
Messages
166
Re: Replacement Tilt/Trim pump?

Thought I should report the results, in case anyone reads this thread.

The Arco motor and housing did the trick. While in there, I took the pump apart, paying careful attention to the location and direction of the springs and check balls. It was gummed up with crud. I did a thorough cleaning, and put it back together with fresh lube on all the parts.

I disconnected the lines at both ends, and blew them out with compressed air. Then I manually raised and lowered the motor until no oil came out of the fittings anymore.

I refilled with fresh 10W30 motor oil as specified by the official Mercury shop manual, and went through the procedure to bleed all air out.

I'd say it works like new now. It's great!
 

rjedney

Cadet
Joined
Nov 26, 2010
Messages
22
Re: Replacement Tilt/Trim pump?

you did a great job on your trim pump. love to see boat people have good luck in fixing their own boat. a big ho ho for you. nasty little brush springs to put in place, always gave me a hard time. raymond
 

littlemoose

Recruit
Joined
May 2, 2012
Messages
1
Re: Replacement Tilt/Trim pump?

Just bought a new motor for the pump for less than $200 from Lighthouse Marine Supply. You might try there. Where does the blue wire go?
 

aussieflash

Lieutenant Junior Grade
Joined
Feb 5, 2011
Messages
1,004
Re: Replacement Tilt/Trim pump?

Thread is from 2010.If you need help start your own thread for much better results.
 
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