Replacing Mercruiser trim pump bracket next weekend... Need advise

asm_

Petty Officer 1st Class
Joined
Apr 11, 2010
Messages
245
I finally decided to replace the trim pump bracket after 3 out of the 6 hole on the originally bracket have rusted thru. Since the space around the pump is limited, I doubt would be able to do the bracket replacement in the boat. So, I will likely have to disconnect the two hoses from the trim cylinders. There are few questions so I don't make fool of my self when the time comes.

- Are either one of those hose pressurized?
- Should I trim the out drive all the way or all the way down when I disconnect the hoses?
- Will I need to bleed the system?

Thanks!!

P1050353.JPG
 
Last edited:

Fun Times

Moderator
Staff member
Joined
May 16, 2009
Messages
8,808
It's your choice to either have the drive down before removing the hoses or support the drive in the up position so the fluid will not spray you/all over as the drive falls down.

When the drive is down, the fluid reservoir is the fullest and the reservoir should always be checked and added while in the down position.

There will be no pressure to worry about as long as the drive is lowered or supported.

As long as you don't rebuild the trim cylinders (rams)... air bleeding is done by raising and lowering the drive about 10 times as it's mostly a self bleeding system.

Have some rags handy as you'll need a few.

Good luck.:)
 

tpenfield

Moderator
Staff member
Joined
Jul 18, 2011
Messages
17,711
Yea, I've got one of those rusty trim pump brackets . . . It seems that the boat manufacturers always put them where water can collect, so the mounting area rusts away.

Outdrive supported by some blocks (or something like that) is the way to go, as Fun Times stated. Expect some fluid to come pouring out. If you prefer, you can connect the 2 lines together as per the picture below (3/8" line coupler) This is a 'scene' from some trim pump work I did a couple year ago.
IMG_2436.jpg


I would expect to have to bleed air from the system, but the less fluid loss, the less of an issue.
 

rickryder

Commander
Joined
Jun 24, 2010
Messages
2,722
I changed mine too...my holes were rotted out...I just bolted angle iron to it to make new flanges..
 

asm_

Petty Officer 1st Class
Joined
Apr 11, 2010
Messages
245
Thanks for all the advise!!

So the key here is to make sure the out drive unit is supported. I may just go ahead and lower it all the way down so I don't have to deal with the supporting the out drive.

Oh yes, believe it or not, in my case, my boat builder decided to put a fishing rod holder right above the trim pump unit. Needless to say, all the salt water are directed to flow over the pump bracket. :facepalm::facepalm:
 

JustJason

Vice Admiral
Joined
Aug 27, 2007
Messages
5,319
The "cleanest" way to do this is suck the oil out of reservoir with a hand oil pump. Remove the trim hoses from the cylinders and hit trim up until no more fluid comes out. Then when you go to undo the lines on the pump, you will get drops at best.
 

HT32BSX115

Supreme Mariner
Joined
Dec 8, 2005
Messages
10,083
The "cleanest" way to do this is suck the oil out of reservoir with a hand oil pump. Remove the trim hoses from the cylinders and hit trim up until no more fluid comes out. Then when you go to undo the lines on the pump, you will get drops at best.

This is how I did mine when I removed the entire engine and drive from the donor boat. MUCH less mess that way. my bracket wasn't all that corroded so I just (glass) bead-blasted mine, and primed/painted it.

I did set it on wood blocks though when I re-installed it so I could get it completely off the "floor" of where it was mounted to keep it from any pooled water that might get in there........... no corrosion on anything now. A stainless steel bracket might help but don't forget that you have other stuff in there (like wiring, relays and connections etc) that aren't SS and will be subject to corrosion if they get splashed with (salt) water.....
 

smassey22180

Petty Officer 1st Class
Joined
Apr 15, 2013
Messages
210
My bracket rusted away also. I put a 1x2 block behind on the top edge and bolted it to the transom. It was hanging about 2" above the floor. The new wood mounted it better than the original bracket ever did and the block at the top had it at the perfect angle against the tilted transom.
 
Last edited:
Top