1975 Mercruiser Tilt/trim issue

[rogerrabbitis]

Hi so end of last season my tilt / trim system was pretty much out of fluid I seem to have a leak I can't find it seems to be in the boat not outside as I don't see any oil in the water but this year we failed up the system and we can get it to go up but not down we have tired to purge the system but still having the same issue I think there is still an air lock but not sure how to get rid of it any ideas ? also options to find the leak I was thinking of dye in the system to help find where it may be leaking from ?

 

[Scott06]

Hi so end of last season my tilt / trim system was pretty much out of fluid I seem to have a leak I can't find it seems to be in the boat not outside as I don't see any oil in the water but this year we failed up the system and we can get it to go up but not down we have tired to purge the system but still having the same issue I think there is still an air lock but not sure how to get rid of it any ideas ? also options to find the leak I was thinking of dye in the system to help find where it may be leaking from ?

Yes for leak detection UV dyes can be a life saver. I got a cheap UV light off amazon and different dyes for AF and Oil, found some leaks more easily than I would have, but you have to clean it all up with brake fluid firts.

I would stand on the drive or disconnect the trim rams to see if its a hydraulic issue or a drive is tuck issue. Lilky crud in the seals

 

[kenny nunez]

As Scott06 posted about standing on he drive to see if that helps to bring the drive down. There is up to 3000 lbs of pressure to raise the drive and only 7-800 lbs on the down circuit. The packing inside of the end of the rams get a build up of crud that most times restricts the down movement.
If this is the problem the rams have to be rebuilt. With the drive raised you can try some penetrating oil on the ram. That might work to loosen the crud build up by raising and pushing down on the drive.
Put your hand under the bottom of the pump, that is where the leak may be. With a 3/8” wrench tighten the high pressure line, they tend to loosen up over time.

 

[rogerrabbitis]

thanks for the tips I will look in to that UV dyes we had disconnected all the lines to purge the system of any old fluid and to try to get rid of the air and I moved the rams up and down no issues they moved freely

I tired last night to force the drive down pushing down on it. I heard the diverter valve down at the bottom of the pump gets stuck and I read you can push down and force it to unstick it that did not seem to work and I can't seem to get it down now

I heard there is a Pressure release valve where would I find that ?

also on the rams there are two lines at the back one closer to the stern and other a by it witch one of those are up and down ?

 

[kenny nunez]

The lines close to the stern should be the high pressure for up. The rams are not left and right, always the most forward port on the rams is for the up circuit.
Do not look for any type of release valve.
If you had a pressure gauge that goes up to 1000 lbs you could test the down circuit pressure. There is an adjustment if your pressure is less than 500 lbs but it is very sensitive.
Is your pump mounted to the transom plate or mounted to the deck?

 

[kenny nunez]

The lines close to the stern should be the high pressure for up. The rams are not left and right, always the most forward port on the rams is for the up circuit.
Do not look for any type of release valve.
If you had a pressure gauge that goes up to 1000 lbs you could test the down circuit pressure. There is an adjustment if your pressure is less than 500 lbs but it is very sensitive.
Is your pump mounted to the transom plate or mounted to the deck?

 

[rogerrabbitis]

The lines close to the stern should be the high pressure for up. The rams are not left and right, always the most forward port on the rams is for the up circuit.
Do not look for any type of release valve.
If you had a pressure gauge that goes up to 1000 lbs you could test the down circuit pressure. There is an adjustment if your pressure is less than 500 lbs but it is very sensitive.
Is your pump mounted to the transom plate or mounted to the deck?

so there is no pressure release valve ?
My pump is mounted to the transom plate

 

[kenny nunez]

Contact West Marine with part #18-2142. Hydraulic ram. They have a close out @$51.42. Normally these rams cost over $300.00.
The “O” ring repair kits are very hard to find as they are NLA.
This is a killer deal and If they have them you better jump on it now!

 

[rogerrabbitis]

Hummm ok I am up at the boat now and I cracked the lines and the lower end goes down and I can go 1/2 way back up and back down and if I go to the top it seems to stick and does not went to go done unless I crack the lines any ideas ? Just don’t want to start buying parts I don’t even know what is causing this

 

[rogerrabbitis]

Contact West Marine with part #18-2142. Hydraulic ram. They have a close out @$51.42. Normally these rams cost over $300.00.
The “O” ring repair kits are very hard to find as they are NLA.
This is a killer deal and If they have them you better jump on it now!

they show on there website none available

 

[redneck joe]

they show on there website none available

i got real excited there for a minute...

Mine slowly drops otherwise works as it should.

I found repair kits on ebay for the rams. I was able to get them in the $60 range but i have seen them up to $120.

life has gotten in the way this year so not even splashed let alone repaired but I did find a shop locally that said when he does the rebuild he will give me the specs on what is in there so one will be able to buy generic. Only thing wont have is the milled brass peice.

 

[redneck joe]

currently none on ebay but here is your part number

64507a 1

 

[rogerrabbitis]

I don’t think this is the rams though as right now everything goes up and down but if I go full up it gets stuck and I have to release the pressure at the hose on the ram it will go down a bit then work till I put it all the way up again ?

 

[rogerrabbitis]

So still getting stuck when funny up/out we have opened it all up and checked check ball valves and and the shuttle valve in these seem to be impossible to get out to service anyone know a good replacement ?

 

[kenny nunez]

If you listen close when raising the pump changes tunes just before full up, try stopping at that point or if it goes go full up try hitting the down switch, that may keep the pressure off just enough. Also keep in mind that if the drive is full up and is exposed to bright sun the pressure in the system will increase.

 

[rogerrabbitis]

good to know thanks for the info it goes up pretty fast I have tired to stop just before and go down we had thought about adding something to stop it from going full up but that also did not work as when it stopped it the pressure went up in the system and would not go down we had to crack the line to get it to move it was not doing anything like this last season the only thing is it ran out of fluid and I did not add fluid till now

 

[redneck joe]

so is it always going up fast? there is a trim and a trailer speed. Could it be in the trim limit sensors?

 

[rogerrabbitis]

ya I would say it goes up slow at first then it does take off when it gets closer to the top this model of pump does not seem to have a a limit switch it just goes to the max both ways but the pressure only seems to be building on the up not the down and from what I understand the shuttle plunger in the pump is getting stuck at high pressure and releases when I crack the line and let the pressure off the other though is a collapsed line but that seems less Likeley from what I find and I seem to have to take the engine out to get to the lines that go behind and to the transom plate I may use here and hop it may clear it's self while I look for a new pump I have the 45060A9 pump version but seems to have gotten replaced with a better model 45060A7

 

[Scott06]

ya I would say it goes up slow at first then it does take off when it gets closer to the top this model of pump does not seem to have a a limit switch it just goes to the max both ways but the pressure only seems to be building on the up not the down and from what I understand the shuttle plunger in the pump is getting stuck at high pressure and releases when I crack the line and let the pressure off the other though is a collapsed line but that seems less Likeley from what I find and I seem to have to take the engine out to get to the lines that go behind and to the transom plate I may use here and hop it may clear it's self while I look for a new pump I have the 45060A9 pump version but seems to have gotten replaced with a better model 45060A7

I don't think it should go slow then pick up speed. You may have two issues going on. Kenny will know better than I but just reading this thread - if you like the boat and want to keep it, you may be better off just replacing with a newer pump, do the hoses and cylinders. You can probably find one on ebay etc used good condition. While this may be harder on the wallet you will probably get a more reliable system and cna go boating.

 

[Bondo]

ya I would say it goes up slow at first then it does take off when it gets closer to the top this model of pump does not seem to have a a limit switch it just goes to the max both ways but the pressure only seems to be building on the up not the down and from what I understand the shuttle plunger in the pump is getting stuck at high pressure and releases when I crack the line and let the pressure off the other though is a collapsed line but that seems less Likeley from what I find and I seem to have to take the engine out to get to the lines that go behind and to the transom plate I may use here and hop it may clear it's self while I look for a new pump I have the 45060A9 pump version but seems to have gotten replaced with a better model 45060A7

Nope, there should be 2, 7/16th nuts at the bottom of the transom that hold the manifold in-place, removing 'em allows pulling the manifold down, to unscrew the inside lines,....