merc power trim and tilt

[davej]

Hope someone can give me some advice regarding my PTT on my old (1987) 60hp 2S merc, which has developed a leak, not bad after 25+ yrs. The trim is the 3 ram type with 2 trim rams and 1 centre tilt ram. The leak appears to be coming from the o ring seal that secures the top up tank to the port hand casting and by carefully looking with an inspection light it dribbles from the back when the system is down and pressurised but only seems to drop a sherry glass full. At least it doesn't appear to be any of the rams leaking. I have a full workshop manual and want to have a go at doing it myself but would like to know if anyone has had the unit off themselves, which by the book indicated that the starboard clamp bracket needs moving and the motor supporting on a host etc. before undoing the unit.

Any advice welcome. Thanks Davej

[9D280]

The biggest problem I found (with a single ram system) is that Merc won't sell you a sinle O- ring, so it's a £50 + VAT set for what sould be a 15p bit of rubber.

I am slightly "off certainty" here, but there were, I think, 2 types of tank (certainly were o nthe single ram ones & mercruiser pumps). One is round with "lugs" for the mount screws, the other square with "dents" in the corners to create the lugs.

Good news is if it's a round one, it should have a round O-ring so go find your local engineering supplies shop. The square ones had shaped seals (although you might be able to bend a suitable diameter ring to fit).


If you do end up buying the Merc kit, I may be interested in the bypass valve.....

[davej]

Thank you very much fior that info, the header tank cover is round with a squire base and 4 hex bolt heads are visible. I am presuming that its straightforward to just go to my local bearing dealer and get n O ring of the correct size or maybe make one up

The thing that concerns me more is just having the confidence to loosen the starboard clamp bracket and remove the ptt unit etc. I have a proper Merc manual.

What do you do about the connecting wiring, is this on a plug?

I think you have totally re built yours so you must have done all this, was it difficult?

I have looked after mine very well and it doesn't show any external corrosion but i guess any of these bolts can be corroded in!

Thanks D

[9D280]

The motor should be on a plug somewhere under your cowl. I retro fitted mine, and dicovered another good old Merc "bespoke design" that meant I would have had to dismantle half the engine to replace a big chunk that would allow me to mount the relay. I have since diverted my wire to a relay box o nthe transom, that also makes a good junction box between the super flexi batt cables to the engine & the more bullet proof (big) cables to the battery.

You might be surprsed how big a standard O ring gets! I do agree getitng the unit off the clamps and siezed bolts is most likely going to be your biggest pain. I donlt know how easywhat I;m about to say actuially is, but could you get down the back with a V. long socket / allen extension (whichever flavour of head yours has!) to remove the tank without taking the unit off the clamps?

[davej]

Thank you for the advice, what I think I will do is have a careful look to see if I can get some sort of flex extension drive down the back to try and loosen the bolts and therefore remove the tank. If not I guess its, support the engine, move the starboard clamp, steering cable etc before getting it off. Thank you for pointing me in the direction of the plug under the cowl. Perhaps I now need to start spraying wd40/plus gas around to prep all the bolts for removal.

Will have a look in the garage later this evening and see whats possible.

Thanks Davej

Originally Posted by 9D280

The motor should be on a plug somewhere under your cowl. I retro fitted mine, and dicovered another good old Merc "bespoke design" that meant I would have had to dismantle half the engine to replace a big chunk that would allow me to mount the relay. I have since diverted my wire to a relay box o nthe transom, that also makes a good junction box between the super flexi batt cables to the engine & the more bullet proof (big) cables to the battery.

You might be surprsed how big a standard O ring gets! I do agree getitng the unit off the clamps and siezed bolts is most likely going to be your biggest pain. I donlt know how easywhat I;m about to say actuially is, but could you get down the back with a V. long socket / allen extension (whichever flavour of head yours has!) to remove the tank without taking the unit off the clamps?

[9D280]

I almost had to do this to put a 3 ram on my old Yam. Then discovered the powerhead was shot, so didn't, but one method might be to try & remove the "tilt" ram from the leg, support the engine either with a lump if wood wedged in between clamp & swivel brackets or a rope up to your A- frame, then disconnect the top of the ram, which wil allow it to tilt out the way or you to motor it down to give you some more swinging room. Just remmeber when you crack open that flange there will be a fair flood of hydraulic fuid dumped. Have an empty plastic tub handy, and remove the bypass screw to fully drain the tank first. Either that or have a big one to hand & catch it as it spews out through the open joint...

Other heads up - remember bog standard Nitrile rings won't last too long if soaked in most flavours of hydraulic oil.....