Trim Pump Fluid

[Alibuma]

My trim pump wont hold my outdrive up either in the driveway or underway on the water. I was going to send it in to be rebuilt so I took it out of the boat last weekend. Tonight I went to drain the fluid out of the reservoir for shipping and found alot of sludge in the bottom of the reservoir (its an older Oildyne metal reservoir pump). The sludge was silver in color, almost metalic looking.

I would guess the fluid is original to the boat (1985), although the dipstick cap does have some screwdriver marks on it. :huh:The cylinders appear to be original, as well. My question is, has anyone ever seen this sludge in the bottom of the pump?

I have read that my problem relates to the valves in the pump body but one marina told me my trim cylinders need to be rebuilt. I was going to start with the pump rebuild and then move to the cylinders if neccessary. I am having second thoughts after seeing this sludge though.

I am wondering what will happen if i just clean it out and put it back in... maybe it will work fine with some fresh fluid? Maybe the fluid was so old and broken down that the valve assemblies were letting it pass? Unfortunatly, the boat is an hour from home so simply "trying it out" will require alot of time. I am hoping someone can tell me to just send it in for repair and dont waste my time putting it back in. Anyone have any experience on these?

 

[earthmover17]

The silver colored sludge you see are the hard parts of the system that have slowly deteriorated over the years. As they pass through the tank they are heavier than the oil so they sink to the bottom. At first you will just see traces of the metal parts in the oil but after a long period of time it turns to a paste at the bottom of the reservoir tank.
As for repair. The fact that it won't stay up tells you there's issues. Have it fixed and be done with it. It's worn out.

Jack

 

[Alibuma]

Thanks Jack. So do you think I am on the right track rebuilding the pump first instead of replacing the cylinders?

 

[earthmover17]

It depends on what the cylinders look like. You may have to go through the whole system. If stuffs in the pump tank it's been through the whole system. I know this is not what you want to here but that's the reality of it. Bare minimum to do it correctly you'll need to reseal the pump, valves and cylinders.

Jack

 

[SeaRay]

I had a similar issue with my boat. I went to a local auto parts store and bought a 1/4" brake line coupler. Then disconnected both cylinder hydraulic lines and coupled them together with the trim all the way up.

If the trim stays up the cylinders should still be good and you are leaking through the pump or valve.

It may actually be easier to get a real short (6" or less) brake line to connect the lines. It was tough to bend the hydraulic lines together to get the short coupler between them. The brake line will give you a little more play to make the connection easier. But I would try to get some trim fluid in the line after making one connection to get some of the air out.

What fixed mine was to pull the check valves apart and clean the poppet valves. I put it back together and so far it is staying up. This might change once I get it in the water but for now it seems to have fixed it. The poppet valves are under the big hex plugs on either side of the pump.

With that said.......I didn't have any sludge in my pump reservoir. If you do it is probably time to replace the pump anyway. There are a lot of parts inside the pump that can give you trouble (check valves, pressure relief valves, the spool, the poppet valves, etc).

You may want to take the old pump and reconnect one hydraulic line and run some trim fluid all the way through the system and back out the disconnected hydraulic line to see what else you get out of it.

There are cylinder rebuild kits. You can get one of those instead of replacing the cylinders.

Good Luck

 

[Alibuma]

Thanks SeaRay. I will try and run some fresh fluid through the pump this weekend.