Tilt/Trim Repair Questions

[Windlasher]

Hello All:

Good morning - Newbie to forum and boats so be gentle.

I just bought an 87 Capri with a Force 85 motor in need of some love. My first boat. I am a motorcycle guy.

Anyway, Got the motor purring like a slightly used kitten. The boat seems to work well and I will concentrate on cosmetics over the winter. I have had it out on the lake about ten times this year.

The Motor will not stay up and drifts down over a period of 3 to 4 minutes. The motor has the tilt motor on the side with the hydraulic pump under it. On land or in water and not moving, the motor trims up and down quite well but will not stay up. The tilt motor sounds just great. There are no obvious leaks that I can tell. Everything that I have read here and other places indicated it was the pump, so I replaced that. Same issue. Obviously, has new oil and the reservoir is full. I have cycled it up and down many times to make sure.

So the motor seems to work fine and has a new pump with the same problem. There are two hydraulic cylinders but only one is attached to the motor/pump which gives me a few questions.

What does the second cylinder/piston on the left do since it is not attached to the hydraulic pump? Is it spring-loaded and just there to balance out the load?

Could it be the motor even though that seems to work just fine and shouldn't the pump stop the fluid from returning to the motor unless the motor is reversed?

MY next obvious choice ar the seals in the cylinders but wouldn't there be leaking hydraulic fluid if the seals were bad?

A lot of articles that I have read say there is a release valve so you can move the motor up and down manually, but I cannot locate it. Do All motors have this and I'm just missing it? The previous owner told me that the tilt and trim have never really worked so I knew this but I would still like it to work.

Thank you guys for any help you might give on these questions is much appreciated. While this is not stopping me from wandering out these last few weeks of decent weather in Minnesota, I would like to have this fixed for next season.

 

[jerryjerry05]

The second cyl. is a shock Like you have on your car.

There is a post, one of the first 4 post in this forum.
It covers the T@T quite well.

You will need to do the leakdown tests described in the post.

Since you bought a new pump??? it's possible the pump is bad??
Yup right out of the box they can be bad

The Chinese probably made it and they produce JUNK!!!

But do the tests to locate the problem.
You can get the fittings at almost any auto store.
I got mine at Auto Zone.
It's possible the pumps ok and the tilt ram is bad??
These can be rebuilt, just a real PITA to get off.
If you do get it off?? make sure you use the right spanner wrench.
You might need some heat?

The tilt cyl. don't usually leak on the outside but leak inside past the seals.

There is NO release valve on Force or Chrysler pumps.

You using 30w motor oil? No trans or hyd. oil.

 

[DunbarLtd]

The second cyl. is a shock Like you have on your car.

There is a post, one of the first 4 post in this forum.
It covers the T@T quite well.

You will need to do the leakdown tests described in the post.

Since you bought a new pump??? it's possible the pump is bad??
Yup right out of the box they can be bad

The Chinese probably made it and they produce JUNK!!!

But do the tests to locate the problem.
You can get the fittings at almost any auto store.
I got mine at Auto Zone.
It's possible the pumps ok and the tilt ram is bad??
These can be rebuilt, just a real PITA to get off.
If you do get it off?? make sure you use the right spanner wrench.
You might need some heat?

The tilt cyl. don't usually leak on the outside but leak inside past the seals.

There is NO release valve on Force or Chrysler pumps.

You using 30w motor oil? No trans or hyd. oil.

Id like to chime in on the Chinese valve bodies. When I tried to fix my t&t issues with it dropping like yours, I bought a chinese pump on ebay and it failed the first time i used it. Had to get a refund and fix the original. The only issue was the orange rubber seal and the spool valves.

The top forum posts explain in detail how to fix your issue like Jerry said. I have no where near the experience most guys on here do but Ive been through all the common fixes and have learned a few things along the way. I have your same boat and motor btw.

And my T&T works flawlessly now ever since i fixed the valve body.

Be careful as there are some small bb's in the valve body when you disassemble it and very tiny washers if you really dig into it. There is a diagram on the internet somewhere of the valve body and where all the little parts go. So be careful and keep track of everything.

Also when taking the spool valves out there are circlips holding them in and i had one fly across the garage and lost it. It was a huge pain finding a replacement that fit. So try not to lose those as well. Other than that, for me, the repair wasnt a big deal really when you read the post in the forum.

I also bought a service manual and it says to use straight 30w motor oil like Jerry said.

One other thing. When reconnecting the hydraulic lines its very easy to cross thread them so be very careful. I added some hydraulic loctite to my threads and its been solid for a couple years now.

there also an oring on the cap for the reservoir so dont forget about that so no water gets in there. Fill it up correctly as well. Overfilling will ruin the motor as oil can be pushed up into it.

 

[jerryjerry05]

The onlt thing in the pump/valve body you can fix is the 2 seals in the shuttle valve.
So if you take anything else apart???? you might not get it back together.
Most cases when someone tries to take it apart.
They try to remove the nut and break the threaded rod and ruin the pump.

 

[DunbarLtd]

Here are the orange seals that are causing the problem.

https://www.ebay.com/itm/10-Tecumse...751?pt=LH_DefaultDomain_0&hash=item5669e43c2f