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View Full Version : TRS Power Trim goes down slowly after sitting



problemchild
10-03-2016, 11:50 AM
Working on a 1979 Criterion for a friend. Just got done redoing the gimble ring, swivel shaft, ect... and am on to the next problem. The trim system operates fine once you cycle it a few times (have to have someone put pressure on the drive to initially get it to go down) So I assume air is getting into the system. The thing is that the drive will operate fine for months when left in regular operating positions, but if left trimmed all the way up for a week or so the problem re occurs. My initial thoughts are maybe a bad valve letting fluid to leak into the reservoir while the drive is up? I can't find any info online with this problem and am fairly baffled.
Thanks for any advice or thoughts,
-Alex

gcarter
10-03-2016, 01:43 PM
The solution for an Alpha, or Bravo, is the "UP" relief valve replacement.
Your pump, if original, is pretty old and it might be time to replace w/a
newer pump.
While you're at it, drain and replace all the fluid.
Also remove the cylinders and see if they'll operate on 100-125# air
pressure, if not, time to change those too. This is important since there's
also a relief valve inside the cylinder, so it may be leaking down internally.
There're good prices for some new cylinders on the SEI site:
http://www.sterndrive.cc/Mercruiser-Bravo-Hydraulics.html
There're more cylinders on the site, ya just have to dig around.

gcarter
10-09-2016, 09:23 AM
I hate it when someone asks a question, you give them an answer, and they never respond.
Is it just no respect?
Maybe I should just not bother.

woobs
10-09-2016, 11:33 AM
I had a similar issue with my Alpha One dropping over time. I originally thought one of the valves in the trim pump was malfunctioning (we had just flushed it). Ultimately I found it was one of my trim cylinders leaking at the shaft seal. A little pi**ed as it was only 2 years old but, hey... this is boating. You couldn't even see the fluid until it had dripped onto concrete and made a mark. I traced the "dribble" to the seal and "voila"! Subsequently, I now use these snap over drive supports (pictured) to reduce the stress on the assembly while on the trailer. They're cheap and available at almost any marina. I got mine at West marine.

Conquistador_del_mar
10-10-2016, 02:48 PM
I hate it when someone asks a question, you give them an answer, and they never respond.
Is it just no respect?
Maybe I should just not bother.

I hear what you are saying George. I don't respond much any more due to this lack of responses. Anyway, I did want to add that when I had problems with the TRS drive not lowering without applying downwards force, I discovered that it was the seals in the rams. I am lucky having a local shop that specializes in repairing all types of hydraulic rams. They repaired a few TRS rams for me, but could not get some of them to unscrew due to corrosion. I have at least one ready to go repaired TRS ram and one brand new in the box TRS ram that I will eventually try to sell. Onwards, Bill