HELP! Merccruiser outdrive piston hyd locked!

chopperbob · Apr 26, 2002

Greetings! I've read a bunch of posts, got the trouble shooting done. I have a 3.0 135 Mercruiser on my SeaRay. I narrowed it down to the stbd piston being hyd locked (I think). The piston is getting fluid (I diconnected the hose fluid came out when I pressed the down switch). The port piston moves fine. Fluid level fine. Fluid consistency fine. Can I try anything else before I take it in to get fixed/changed? Thanks in advance! Bob

chopperbob · Apr 26, 2002

Re: HELP! Merccruiser outdrive piston hyd locked!

Sorry, further info, it's a 96 motor, the outdrive was left up for about a year. (I know, I know...my fault, but I was whisked away to go overseas, then this whole war thing came along...) Chopper

clanton · Apr 26, 2002

Re: HELP! Merccruiser outdrive piston hyd locked!

Loosen the 2 lines on each cylinder, try and push the outdrive down, tighten lines run half way up, then try the down trim

chopperbob · Apr 29, 2002

Re: HELP! Merccruiser outdrive piston hyd locked!

Hi Clanton, thanks for the reply. I did what you said, no luck. Here's what I did. The port piston works fine. I noticed that the port piston spins freely (with some resistance of course), the stbd piston does not spin at all. I was able to unscrew it from the piston housing, and pull it out. Basically, it's just stuck in it's housing. It worked fine before the season was over. So, I know it used to work (ie - it wasn't damaged).

clanton · Apr 29, 2002

Re: HELP! Merccruiser outdrive piston hyd locked!

Are you saying that you have the rod and piston out of the cylinder, and the end cap is stuck to the rod or you have the piston rod and end cap out, and the piston is stuck in the cylinder?

chopperbob · Apr 30, 2002

Re: HELP! Merccruiser outdrive piston hyd locked!

I have the rod and piston out of the cylinder, and the end cap is stuck to the rod. Before I unscrewed it, I could twist the rod inside of the end cap, but it rotated with much resistance. The port rod/piston rotated rather smoothly. It feels like the rod is just stuck in the end cap.

clanton · Apr 30, 2002

Re: HELP! Merccruiser outdrive piston hyd locked!

If you can get the piston off, heat the cap in hot water, lubricate both ends of the cap with Blaster,ATF,or mix of ATF/STP. You should be able to move the cap by heating, lubricating and keeping the pressure on the cap by using 2/4 and hammer lite tapping. I think you will find corrosion around the seals. If the rod is not damaged you probley can save it.

chopperbob · Apr 30, 2002

Re: HELP! Merccruiser outdrive piston hyd locked!

Don't understand why it is stuck, the piston was full of fluid when I unscrewed it, well lubricated. It was just left in the up position for a while and seems seized up. Like I said, it worked fine, never hit bottom or anything. Tried hammering it in to get it to move while it was screwed into the cylinder, no luck. Should I try soaking it in liquid wrench or something?

chopperbob · Apr 30, 2002

Re: HELP! Merccruiser outdrive piston hyd locked!

OKAY, I'll give it a try.

my new fishmaster · Apr 30, 2002

Re: HELP! Merccruiser outdrive piston hyd locked!

Things this new dont just break I would take off the lines and make sure they are open before trying to go up and down manualy. If you can find some rust spray like Wd 40 or Pb blaster one of them is ok for rubber I think. Read all the labels before buying liquid wrench is bad for rubber.

clanton · Apr 30, 2002

Re: HELP! Merccruiser outdrive piston hyd locked!

I think you will find corrosion inside the cap the rod is stainless and the cap is aluminum, you will find a gray powder under the cap.

chopperbob · May 1, 2002

Re: HELP! Merccruiser outdrive piston hyd locked!

Guess who's putting his boat in the water this weekend...I AM!! I did what you said, heated the metal up, and screwed it into the cylinder, slowly (and forcefully) worked the rod inward about 1/2" by twisting and pushing it. I was loosened up enough so that the hydraulics could move it (slowly) in and out. There was black residue along the rod when it was moved back out, I assume it was dried up oil, sticky. Kept working it in and out (sounds dirty, I know) while lubricating the rod. Then hooked the two rods up with the connecting rod, and let them move together, works fine!! Had to refill the reservoir of course. Thanks alot guys!! See you on the water!! Chopper

HELP! Merccruiser outdrive piston hyd locked!

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