Gentlemen, assistance required....

[fogducker III]

At the end of last season I started having some trouble with my trim/tilt cutting out at times. Narrowed it down to the trim pump motor, something internal cuts the power when I try to trim up at speed.....works fine on land but as soon as there is pressure on the system it doesn't work at times, specifically when trimming up at speed.

So I ended up finding a brand new Volvo Penta trim pump unit, for dirt cheap, which I am going to swap in, it was pointed out that the fittings on the Volvo unit are metric so I will source adaptors for that, other then that, everything else hooks up fine, just have to change a couple of ends on some electrical leads. I have a Bravo I with the stock Mercury trim/tilt pump at present.


My question is, what is the best, easiest way to "purge" the fluid from the system? At present it is milky and I know moisture is in the system, I plan on rebuilding the trim rams which is probably the source of the moisture. I understand the principle of rebuilding the rams but have never done it, anybody who has done it, is it straight forward?

Do I just remove the rams, rebuild them, unhook all the hoses and blow them out to remove all fluid, replace the pump unit, hook-up, fill-up and go...? Thanks for any advice......:yes:

[VetteLT193]

I don't know about the actual rebuild as I am not a hydraulics guy...

As far as the rest of the process you have it down. put the new or rebuilt rams on after getting all of the old fluid out. fill up reservoir and trim up and down a few times to get the air out.

SEI has rams for pretty reasonable if you don't go the rebuild route.

If you have water in the system that might be the root cause of the failure. If it were me I'd do the rams and a full system bleed and try it.... it might be just fine when there is no water in there.

[fogducker III]

I don't know about the actual rebuild as I am not a hydraulics guy...

As far as the rest of the process you have it down. put the new or rebuilt rams on after getting all of the old fluid out. fill up reservoir and trim up and down a few times to get the air out.

SEI has rams for pretty reasonable if you don't go the rebuild route.

If you have water in the system that might be the root cause of the failure. If it were me I'd do the rams and a full system bleed and try it.... it might be just fine when there is no water in there.

Thanks, I hear what you are saying.....I looked into buying new rams, the cost with shipping, customs etc. for Merc rams or "after market" ones are not cheap either way.....the ones I have are in good shape and work well when the system works. The original pump unit is in sad shape, all electrical is tired and corrosion has set in, I have the new Volvo system that I believe I paid $70 for.......:yes: So I thought I might as well use it, will save some grief down the road I think......

Once I sort out the rams I will check all fittings and connections and redo as needed, other then that, I don't believe the Volvo pump itself is any different then the original??? It should pump at the same pressure and speed, or close to it...?

[VetteLT193]

I think the rams can get corroded internally so you might want to knock one of your rams down to see what is inside before committing to the rebuild...

As far as pump pressures... I would assume they would be the same, or close, but you know what "assume" can do.

If you do end up with the rebuild can you post pictures for us? It is an endeavor I wouldn't mind doing but guidance is few and far between.

[fogducker III]

I think the rams can get corroded internally so you might want to knock one of your rams down to see what is inside before committing to the rebuild...

As far as pump pressures... I would assume they would be the same, or close, but you know what "assume" can do.

If you do end up with the rebuild can you post pictures for us? It is an endeavor I wouldn't mind doing but guidance is few and far between.

Good advice.....I certainly will "record" the ram rebuild........from what I have read, the "guts" of the ram are stainless so not sure if corrosion will be an issue, more likely the rubber seals have worn out....:confused:


Not sure what I will find, but I will let you know, thanks again for the input.

[fogducker III]

Trim ram rebuild kits are on order, I disconnected all the lines and blew out all the milky fluid, swapped out the old pump unit for the new Volvo unit, DAMN IS THIS THING QUITE.....basically a straight swap other then the outlet fittings, found those at the local hydralics shop, also the power and ground leads needed different connection ends..........other then that I am very happy with the new set-up........heading out later today to test it out as well as a different prop I got back from my local prop shop..........Mirage Plus labbed 27P with added cup, got great numbers last time I used this prop before he added some cup, the bow was a little "heavy" but this should bring it up a little......:crossfing:

[VetteLT193]

it has to be freezing up there... good luck on the run, should have a few extra HP from the cold air :cool:

[fogducker III]

it has to be freezing up there... good luck on the run, should have a few extra HP from the cold air :cool:

Suppose to be sunny, no wind and in the low teens (celsius) warm enough for me......:stan::wink:

[VetteLT193]

Suppose to be sunny, no wind and in the low teens (celsius) warm enough for me......:stan::wink:

Better weather than here. it is about the same temp but it's raining here. :bonk: have fun, I'm jealous! Maybe this weekend we'll be boating

[gcarter]

The trim pumps are capable of producing about 1K PSI and will operate an otherwise nearly frozen cylinder.
If, when you disconnect the cylinders, you find they are not free, when you manipulate them by hand (i.e., clamp it in a vise and try to move the rods w/a broomstick or something similar in the rod mounting ring), then you might not be able to rebuild them properly......
Just so you know, they should be free and take very little effort to slide in and out.

[fogducker III]

The trim pumps are capable of producing about 1K PSI and will operate an otherwise nearly frozen cylinder.
If, when you disconnect the cylinders, you find they are not free, when you manipulate them by hand (i.e., clamp it in a vise and try to move the rods w/a broomstick or something similar in the rod mounting ring), then you might not be able to rebuild them properly......
Just so you know, they should be free and take very little effort to slide in and out.

They are free moving and in good shape, just need to replace O rings to make sure they stay that way, thanks for the input though...:wink: