PT&T Blown - Hit A Sandbar

[JoLin]

I grounded the motor at about 20 mph yesterday. When I got it stopped the surrounding water was full of oil. PT&T is inoperative- motor will shake up and down a bit when I hit the trim switch, but won't move any appreciable amount. I assume at the moment that the oil was hydraulic fluid, but will know more later.

I'm pulling the boat out of the water today and will attempt to remove the PT&T unit and either take it for service or rebuild it myself. The water pump may be full of sand so I'll service that, too.

Anyone know what happened, or why the motor wouldn't kick up on a hard hit instead of blowing seals in the PT&T? Is my experience unusual? I guess I'm unclear on the design of this thing.

 

[jonesg]

Re: PT&T Blown - Hit A Sandbar

what model and year?

its just speculation until you get into it and see what failed.

 

[JoLin]

Re: PT&T Blown - Hit A Sandbar

Hi, jonesg,

Model and year are in my signature= 1997, 175 hp with Fastrac.

I'm still working on getting the unit out of the motor bracket. It's slow going. I have the bottom pin nearly out but the top one is real stubborn. I'm using 1/2" plumbing pipe as the "drift" along with a 3-lb. hand sledge. Applying heat and WD-40 regularly. Might have to take the rest of today off. My hammer swings are getting weak.

Whatever's leaking, the fluid is coming out the back of the unit and dripping down the face of my motor bracket.

 

[JoLin]

Re: PT&T Blown - Hit A Sandbar

Finally got the unit off the motor bracket. Fun job.

The only place fluid can escape out the rear of the assembly, is through an air bleed hole behind the manual release screw/valve. With the valve screw open I pushed down on the large center rod, and a little fluid blew out of the bleed hole.

Now, that relief valve is only supposed to depressurize (let air escape) the system so you can raise and lower the motor leg manually, right? How did fluid get in there? I'm looking at the parts catalog exploded assembly and I can't figure it.

I'm debating whether to get the parts and rebuild it myself, but it would be nice to know if any of the experts here could lead me to the most likely failure point so I can look for it as I go. Thanks!

 

[jonesg]

Re: PT&T Blown - Hit A Sandbar

Mine is a J150 but similar, there isn't supposed to be air in hydraulic systems, the manual relief lets fluid pass from one side to the other.
I had to bleed my system but it only required manually cycling the leg up and down a few times and it started working after that.

There are 2 pressure relief valves in the main tilt piston, they're to provide shock absorbtion impact relief.

When I unscrew my manual relief valve no fluid come out anywhere as I manually tilt the leg up and down.

Now that you have it out of the bracket, have you tried applying voltage to the pump?

btw, a big balljoint press with an elec impact driver moves stuck pins out easily. (...or air hammer )

I wonder if the manual relief valve blew out instead of the impact relief valves, easier fix if it did.

The impact valves reseat themselves,
but a blown manual valve would just remain blown. Make sense?

If the pump is working but the pistons won't cycle then its plausible the manual valve is leaking fluid from one side to the other.
The factory service manual just suggests swapping with a new valve to test.

 

[JoLin]

Re: PT&T Blown - Hit A Sandbar

"The impact valves reseat themselves,
but a blown manual valve would just remain blown. Make sense?"

Yeah, that makes sense. If NOTHNG is supposed to come out of that "hole", then I suspect a problem there (though I wonder why it's there). Pushing down on the big piston, with the valve open and fluid in the system, some fluid came out. With no fluid, I got a puff of air. From what you said, neither sounds right.

The motor is good, btw. Runs in both directions, but with the assembly empty of fluid I of course see no piston movement. I also have no spare parts to swap around to see what might be busted and what might not. I'd like to get back on the water, too.

I don't have the Johnson "accessory" manual for this job, but my Seloc looks pretty detailed for this unit. I've read through the rebuild procedure a couple of times and I think I can do this in a day or less. With rebuilt units running 700-800 bucks I think I'll buy the rebuild kit along with a new manual release valve and give it a shot. Evinrude.com parts are a little pricey, but the parts come very quickly and it's all oem. The only tool I need to buy is a spanner wrench which I can get from Amazon. I'll make my final decision tomorrow.

I still wonder why this happened. Nobody plans to hit something, but the motor oughta be able to take a shot without blowing hydraulic fluid all over the water. It was plowing through sand, too, not rock. Just one of those things?

Thanks for sharing your ideas- I appreciate it!

 

[jonesg]

Re: PT&T Blown - Hit A Sandbar

700-800 bucks bah!

It might take all day but so what..

My first timing belt took 3 days, second time took 45 minutes.

 

[JoLin]

Re: PT&T Blown - Hit A Sandbar

I hear ya. I've been a shadetree mechanic for nearly 40 years, but outboards are brand new to me. The reseal kit is ordered, including a new release valve. Ridiculous price for that one, but I think it's the real source of the problem. After all the effort it took to get it off the bracket, tho, it's not going back on until I've replaced all the innards.