Tilt and Trim 150hp Mercury v6

DKPZ64

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My trim is bleeding off and I have used the relief valve to let air out and I seen fluid coming out of the middle of the reservoir where the top connects to the bottom. How fast are you supposed to let the motor drop when letting off pressure? It still works like it should up and down but it just bleeds off. I think I need to replace the orings in it.
 

Chris1956

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What year is the motor? 3 cylinder PTT unit?

When you say relief valve, do you mean PTT manual release?
 

DKPZ64

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What year is the motor? 3 cylinder PTT unit?

When you say relief valve, do you mean PTT manual release?
Sorry for the late reply, I did not get any notification. It's a 85. The relief valve on the lower right side below the trim motor. I believe it is 3 cylinders. it has the two smaller ones in the back and the main one in the middle that lifts it up.
 

Chris1956

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I would make sure the manual release is tight. I am not sure of the tightening spec, however.

Is there fluid leaking out of the unit? Has the reservoir been topped off and the unit bled?

The center trim cylinder rides on a pin drilled to allow hydraulic fluid to flow to the trim cylinder. After a while, the casting where the pin meets the trim cylinders can wear or corrode and then it leaks. If you have a leak there, you need to see if the original casting sealing surfaces are still intact.

The good news is that complete, new PTT units are avail aftermarket.
 

DKPZ64

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I would make sure the manual release is tight. I am not sure of the tightening spec, however.

Is there fluid leaking out of the unit? Has the reservoir been topped off and the unit bled?

The center trim cylinder rides on a pin drilled to allow hydraulic fluid to flow to the trim cylinder. After a while, the casting where the pin meets the trim cylinders can wear or corrode and then it leaks. If you have a leak there, you need to see if the original casting sealing surfaces are still intact.

The good news is that complete, new PTT units are avail aftermarket
Everything is tight and toped off. The only time I saw any leaks is when I was bleeding the air out of the system and I think I let the motor drop to fast and fluid came out of in between where the top of the reservoir connects to the bottom of the reservoir. I can raise the motor and it will bleed off to the small pistons and then bleed off the rest of the way overnight.
 

Chris1956

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Fluid should never come out of the PTT unit when bleeding. If it does, you have found an issue.

To bleed that system, trim it all the way up and fill the reservoir. Now cap the reservoir and cycle it down and up, topping off and capping the reservoir. Repeat as necessary, until all the air is out of the system and the fluid is clear.

If the manual release is tight, and she still leaks down, without any fluid leaking, it is time to look for a rebuild kit.
 

DKPZ64

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Fluid should never come out of the PTT unit when bleeding. If it does, you have found an issue.

To bleed that system, trim it all the way up and fill the reservoir. Now cap the reservoir and cycle it down and up, topping off and capping the reservoir. Repeat as necessary, until all the air is out of the system and the fluid is clear.

If the manual release is tight, and she still leaks down, without any fluid leaking, it is time to look for a rebuild kit.
What is the PTT? Is that the pressure relief valve? I got a O-ring kit that has everything for the reservoir motor seals for the short cylinders and new relief valve but it don't have anything for the middle cylinder it has it's own kit.
 

Chris1956

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PTT is Power Trim and Tilt unit.

Gee, I would first install the new manual release valve and retest.
 

Dukedog

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and I seen fluid coming out of the middle of the reservoir where the top connects to the bottom.

if i'm readin' this right it indicates it has a leaky seal between tha motor and tha pump......
 

DKPZ64

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There is usually an oring between the PTT motor and the pump.
Thanks for all the reply's...

This is the only place I have seen any fluid at all and like I said The only time I started seeing it there is when I let the motor drop to fast. That's why I asked How fast are you supposed to let the motor drop when bleeding the air out of the system?
 

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jimmbo

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If the Fluid is coming out of the housing, then the Housing is damaged, or the O-ring is bad.
If the Fill Screw is not in Place, Fluid will spray out of it if the Pump is operated.
I had an inline with the same Trim System, and I don't recall there being a Bleed Screw on it. Bleeding the Air out was done by filling the Reservoir, putting the Fill Screw on tight, then cycling the System several Times and checking the Fluid Level, adding until it remained at the Proper Level
 

Faztbullet

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System is self bleeding.....add fluid, cycle several time them SLOWLY open fill port in full up position, not the manual release
 

DKPZ64

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If the Fluid is coming out of the housing, then the Housing is damaged, or the O-ring is bad.
If the Fill Screw is not in Place, Fluid will spray out of it if the Pump is operated.
I had an inline with the same Trim System, and I don't recall there being a Bleed Screw on it. Bleeding the Air out was done by filling the Reservoir, putting the Fill Screw on tight, then cycling the System several Times and checking the Fluid Level, adding until it remained at the Proper Level
The only time fluid comes out is when I use the manual release valve. I think I let the motor come down to fast and it messed up the oring. But it was still bleeding off before I started seeing the fluid. I could raise the motor and it would not stay where I left it. It is still usable the way it is now, it goes up and down It just don't stay where you put it.
 

jimmbo

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If the Manual Release Valve is Open, the Motor will drop down.

What do You mean, "I think I let the motor come down to fast"?
 

DKPZ64

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If the Manual Release Valve is Open, the Motor will drop down.

What do You mean, "I think I let the motor come down to fast"?
It came down pretty fast. That's when the fluid came out of the joint between the top and bottom of the reservoir. That's what my first question on here was, How fast are you supposed to let the motor come down when using the pressure relief valve?
 

jimmbo

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What you are calling a Pressure Relief Valve is like the Manual Release Valve, to be used to Raise the Motor in case of Trim System Failure. Yes it can be used to lower the motor. But I recall, that it would only go down to the Highest Trim Setting. Maybe it would drop lower if Prop Thrust was increased. It is over 25 yrs since I had the Motor with that Trim System, but I did raise and lower motor that way when the Battery was Dead. On the Engine was running I could use the Power Trim Pump, as the Motor was trying to charge the Battery.
I just opened the Valve enough for it to lower, but more to make it easier to Lift it.
The Speed of it Dropping shouldn't have pushed the O-ring or housing out of Place.
That housing has been known to Crack, if someone is overzealous with the Torque when tightening the Filler Cap.
 

DKPZ64

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What you are calling a Pressure Relief Valve is like the Manual Release Valve, to be used to Raise the Motor in case of Trim System Failure. Yes it can be used to lower the motor. But I recall, that it would only go down to the Highest Trim Setting. Maybe it would drop lower if Prop Thrust was increased. It is over 25 yrs since I had the Motor with that Trim System, but I did raise and lower motor that way when the Battery was Dead. On the Engine was running I could use the Power Trim Pump, as the Motor was trying to charge the Battery.
I just opened the Valve enough for it to lower, but more to make it easier to Lift it.
The Speed of it Dropping shouldn't have pushed the O-ring or housing out of Place.
That housing has been known to Crack, if someone is overzealous with the Torque when tightening the Filler Cap.
Has nothing to do with the filler cap. That is not where I'm see the fluid at. Look at the pic I posted. There was no fluid there until I opened the valve up, I think to far and the motor dropped really fast and that's when I seen the fluid come out of where I have circled and no where else. But even before that the unit would bleed down. I think it had a bad Oring and that just help it even more if you know what I mean.
 

jimmbo

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Reread my last Sentence, regarding the Filler Cap.
 
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