Trim/tilt problem or check valve issue?

[wranger93]

Hey all, new here, great site and really good advice from what I've read. I have a 1988 (pretty sure) 115 Mariner on my boat with the original trim/tilt system that it came with. It was leaking and got water in it, so I followed the book and rebuilt the entire thing...every o-ring, seal, etc. in both rams and the tilt cylinder, plus a new pump w/ motor. Everything seems to be working fine except...when the tilt gets down to the rams, it more-or-less stops right there (pump still running of course). If I push down on the outboard it, it goes down/in about 3/4" and pops right back up...just like the book says...so I assume I have air trapped in the big cylinder...? I have cycled this thing WAY more than I should have had too...sometimes it burps (self-bleeding system supposedly), sometimes it doesn't, but hasn't yet changed the performance. If I put pressure on it while going down, sometimes it will go all the way down...but it doesn't screech or sound like it's processing air when it gets to the lowest point??! Any suggestions on verifying this is trapped air? Drain the system and start again...? Could it possibly be a faulty check valve (if mine even has that)? I've also noticed the hydraulic fluid is generally frothy when I open the filler plug to check the fluid (after cycling it of course). Thanks!

 

[wranger93]

Sooo....unfortunately I didn't get any responses/suggestions to my post and was forced to take the entire tilt/trim assembly back apart and back-track all of my steps. Lo & behold, I had not torqued the piston (inside the tilt cylinder) back to where it should have been. I had hand tightened it and set it aside to finish cleaning other parts...then forgot to go back and finish that part...thus when the PSI's were way up, the check valve was letting fluid just flow through the piston and would not build enough pressure to pull the motor all the way down through the trim cylinders AND gave it the feel of air in the system. Once I re-cleaned everything and double-checked all my work and got it back on the boat for a second time...it works like a charm now!! For those amateurs that look at a job like that and say no way...I say go for it! I had my SELOC manual out and broke the whole thing down, cleaned it, and put it back together twice...it is NOT that hard once you get in it! I couldn't even begin to tell you the money I saved doing this job myself! The time wasted was my own fault of course because I got careless...but all told I think I still got it done faster than any local repair shop would've (they all said at least 2 weeks!). I will warn you...the Quick Silver o-ring kits (2 kits required for this job) are not cheap, so be careful with them and lube them well and take your time when you're putting it back together so as not to pinch or gouge any of your rings...its all pretty tight during reassembly!

Last...does anyone know where to find any kind of replacement plug assembly for the trim reservoir cap (Part# 19-99609A 1, Plug Assembly QPD)? I have looked every where and all I can find is "No Longer Available" or "Sold Out." Mine was all tore up before I started this job and is way worse now! THANKS!

 

[Rodney Williams]

eBay maybe..... otherwise I'd check at some of the area shops & see if they have any junk units lying around. I'm pretty sure there's more than one junk Mercury trim unit around.