TOPIC: 78 tilt and trim

I am fighting a tilt and trim. Need some help. The motor pushes it up but won't drop it down. it is a 85 ETLR 78C. Pump runs but on the down only drops it an small amount then stops. like it is releasing the pressure. How do I best check if it is the pump or somthing else. Thanks

Surprised none of the experts have chimed in yet. I am by no means an expert, but could it be that the fluid in the pump needs to be changed or has water in it? Maybe some water got in and there is rust blocking the return path for the fluid.

Not sure if the motor has the same amount of pressure pumping out (raising) versus pulling in (lowering) Maybe you have a bad solenoid for the down circuit? I think most set up's have 2 solenoids - one for up and one for down. Perhaps the down solenoid is overheating or losing contact and that is what is causing the pump to quit.

I would not think it is the pump if it is working fine to lift it. Probably with the connections or the solenoid on the down circuit. See if you can find the solenoids by the transom and have someone cycle the trim up and down. You can then figure out which is for up and which is down. You can then test by switching wires from the solenoids that go to the lift motor - take the wire from the "up" solenoid and switch it with the "down" solenoid. My guess is that you will do that and find the the motor now goes down but doesn't go up.

Just my guess - HTH

I will try that. motor doesn't sound like it is running any different but I will try what I can. Thanks

looking at the drawings I am missing the springs on the pump control piston. could that be part of the problem? it did work that way before.

Its worth a try. I know that Cal / 63Sabre has messed around with a bunch of OMC T&T, but he is on vacation and has not been on the site too much. You can try to send him a pm and see if he gets back to you. Otherwise Ed MC always seems to have the right answer!! Try him if you aren't having any luck

Are you talking about #s 19 and 76 on Marineengine?

www.marineengine.com/parts/johnson-evinrude-parts.php?year=1978&hp=85&model=85ETLR78C&manufacturer=Johnson§ion=Power+Tilt+And+Trim

Those do seem to be related to the pressure release on the pump. They look like internal parts - do you have the pump apart? If so, it is pretty dirty? The other thing is that the motor itself might need to be filled with mineral oil. The lift I have for my 1974 is supposed to be filled, and if they are dry the motor can overheat and shut down.

it would be #4 on either side of #63 that I am looking at. Don't have the pump apart at this point.

Did you see a "+" stamped on the part? I think the original version didn't have springs while the later models did.

didn't see a +

Per marineengine, the ones needing the springs would have the "+"

Any luck with the T&T?

sorry I haven't gotten to it yet. the current temp is more suited to a boat on the lake than working on the one on the trailer. from the drawing i figured out that i had bought the wrong oring. have to pick that one up now. I currently think i need to pull the t&t enough to access the transom side and check the function of the valve there. #64 from the drawing in the link.

The extent of my boating has been this website and looking longingly at the boats in the garage!! Too busy studying for my CFP test next Tuesday. Once August hits I will be full bore working on boat projects and enjoying some time on the water.

Need more help. I opened the connection on the top of the tilt cylinder. Now I can't get it to stop leaking. did I mess up a seal?

Check to make sure the tubing isn't binding. I had that happen when I was messing around with my T&T. Even though the connection felt tight the tube wasnt seating correctly. I don't recall any seals though - just pipe fittings

Mark. Just got back on Friday night. Busy week coming up cleaning up the mess around the house after 5 weeks
I'll see if we can take a peek at it this week sometime.
Cal

Thanks Cal!! No hurry though - heading to Vegas tomorrow and will be gone till Thursday. Wait till you see some of the new toys. Hint - check out Merc Outpost

Sounds like you missed or pinched an "O" ring. Most of those are standard fitting rings. If you take the old one(s) out and go to a local hardware or auto store you can get a perfect match for pennies. On the other problem it sounds to me like you are low on hydraulic fluid. A good time to drain the whole system and refill with clean stuff. Standard DOT3 brake fluid from the auto store or walley world will do the trick and has good water rejection capabilities.
Cal

Cal,

Did you mean DOT 5 rather than DOT 3? The following is from a Wikipedia page on DOT 3 brake fluid.

“DOT 3, like DOT 4 and DOT 5.1, is a polyethylene glycol-based fluid (contrasted with DOT 5, which is silicone-based). Fluids such as DOT 3 are hygroscopic and will absorb water from the atmosphere. This degrades the fluid's performance, and if allowed to accumulate over a period of time, can drastically reduce its boiling point. In a passenger car this is not much of an issue[citation needed], but can be of serious concern in police vehicles, racecars or motorcycles[citation needed]. DOT 3 has been all but replaced with the superior DOT 4 as there is little cost difference between the two.”

Also, the tilt/trim system O rings and seals are not compatible with DOT 3 fluid. EDPM rubber is used in brake systems to resist glycol based brake fluids.
OMC has their factory recommended tilt/trim fluid, but Dexron II or any similar ATF will work well and protect the pump better than brake fluid.

Don

Well Excuuuussssee meeee
Just goes to show this old shade tree mech. is advancing in age without keeping up on current affairs.
Good to know and glad you corrected this. Got some useful info. TKS.

Cal , glad to see your back. I would use dexron 6. it handles heat and high pressure. greg

It is finally working. Not overly sure what the underlying issue was but IF it happens again I have an idea that I will try. Ended up pulling the motor off the transom. (Thanks Del) needed two o-rings to fix the leak I caused. $1.03 at napa. removed the 3 plugs on the back side. the one under the pump was under pressure. I think that pressure locked things up. after reassembling everything it worked great.