Tilt/trim issue AQ151C SP-A

krrrrayzk

Recruit
Joined
Jun 8, 2015
Messages
1
I've been getting by with this issue with the hydraulics for some time, but it is irritating. With the stern in the travel position, it only takes a day or two, and it gradually falls down to the "0" or vertical. Also, with the boat in use, I observe the number on the power trim panel, which shows the stern gradually creeping up. This creates the need to be correcting the stern pitch fairly frequently, which is bothersome. Wondering if this points to any one issue/component, or will I just have to overhaul the system? Thanks for any help.
 

billbayliner

Chief Petty Officer
Joined
Jun 30, 2006
Messages
553
If I am interpreting this right this is the issue. One of the piston bi-directional sealing rings in one of you trim cylinders is leaking by. Thus balancing the pressure on either side of the piston. With this said it drifts down and the cylinders need rebuilding. (Kits are on Ebay)

If not the cylinders then it is the pump check valve issue....

Here is a Volvo Bulletin ... This is to a particular trim pump BUT still same theory on all designs.



This SB applies to:
- All DP-290 with Power Trim.
- All SX, DP-S drives where the shield designation starts with ??SX-M??.
Previous shields had a different type of pump and pump house.

Distribution: Date: 11-1999 Binder: B C Page: 1(1)
44?5 2 01
Volvo Penta has received reports that the drive does not stay in the raised position, it slowly
lowers down in some cases. It can also happen that the drive slowly lifts during operation
This is almost always caused by dirt around the up/down valves in the pump housing.
If the above problems occur, follow the instructions below to remove any dirt from the up/
down valves.
1. Apply maximum trim to the valves.
2. Undo the two bolts (1). (These can be quite tight).
3. Remove springs (2).
4. Use a magnet with max. diameter 8 mm to pull the pistons out (3).
5. Clean the valve seats and pistons with a rag. Do not use solvents, this could damage the
rubber ring on the
piston.
6. Re-install the components. Torque bolt (1) to 50-65 Nm.
7. Fill up the Power Trim tank with ATF hydraulic oil.
A filter has also been added by the Power Trim hose unions with the valve housing.
This filter has been introduced in production on SX/DP-S as from TSK serial no.
4111621407**. The filter can not be used on TSK units produced before this serial number.
** Will be introduced on DP-290 during 1999
 
Top