I have a mercruiser I/o . I need to manually get the lower unit in the up position .can I simply disconnect the lower ends of the hydraulic pistons to lift the lower unit?

Probably needs the cable adjusted. Put the lower unit on and adjust the cable per the instructions for your lower unit.

That looks like a block casting number.
Mercruiser GM 5.0l Vortec Engine Core Block 10243878

Should be a badge tag on top of bell housing or next to starter that will give you more information.
If you strike out finding a badge, I would mic the bore and piston before I ordered any parts.

no
hydraulic system self bleed from repeated use
what you have are piston seal worn, cylinder walls damaged allowing bypass of oil or faulty control valve units

Removing the motor would be my last resort. That is a bunch of work.
Be sure that you are totally sure that you can't get the hose while the engine is in.
Remember that working with hydraulics can be dangerous. Lower or support all equipment, and releive hydraulic pressure before disconnecting lines.
HINT: If the ends of the hose are accessible, disconnect them and tape a piece of cord to one end. Then ease the hose out of the restricted space. Leave the cord there, and use it to ease the replacement hose back in.
STAY SAFE!

Yes, but if you do not disconnect the pistons, you will have to push very hard because you will be forcing the hydraulic fluid back through the pump. Behind the rear side windows there is a hydraulic piston on both sides. They look like shock absorbers (See pic.). At the top is a rod that is bolted to the folding mechanism. Unbolt the rod and push it back down into the piston on both sides. You now have a manual top. FYI, this works for most convertibles.

Unhook the cable connection from the shift lever at the lower.Try to shift by hand with a cresent wrench,(small,and don't force).Sounds like you've a keeper dropped off in the lower.It's easy enough to pull the lower apart,but better have someone there that knows the unit or buy a repair manual for that lower.

Pacifica 2006-2008
Brake Calipers

• REMOVAL & INSTALLATION

Print I hope this helps,Good luck

Removal & Installation


NOTE Using a brake pedal holding tool, depress the brake pedal past its first inch of travel and hold it in this position. This will isolate the master cylinder from the hydraulic brake system and will not allow brake fluid to drain out of the reservoir while the brake lines are open.

1. Before servicing the vehicle, refer to the Precautions section.
2. Remove or disconnect the following:
   
   Negative battery cable Rear wheels Banjo bolt retaining the brake hose to the caliper. Be sure to plug the end of the brake hose or cover it with a plastic bag to prevent contamination from entering the hydraulic system. Caliper guide pin bolts Caliper assembly from the brake adapter by rotating the bottom of the caliper away from the rotor, then lift the caliper with the pads away from the adapter abutment Brake pads by pushing (outboard) or pulling (inboard) from the caliper fingers and piston
   
   

   Fig. Brake hose banjo fitting (1), caliper guide pin bolt (2), caliper adapter (3), caliper (4), copper seal washers (5) and banjo bolt (6)
   
   

To install:

1. Completely compress the caliper piston
2. Install or connect the following:
   NOTE The outboard pads are side oriented, make sure the spring clip is installed so it is positioned downwards when the caliper is installed.
   
   
   Inboard pad clip against the piston cavity and press the pad until the clip is seated making sure the pad backing plate is flush against the piston
   
   
   Outboard pad making sure the locating pins are positioned against the ramps. Slide the pad onto the caliper and ensure the locating pins are squarely seated into the holes on the caliper and the pad is flush against the caliper fingers.
   
3. Make sure the abutment shims are in place on both slide abutments.
4. Retract the caliper guide pins to clear the caliper adapter bosses.
   
   Brake caliper. Staring with the upper end, position the caliper and shoes over the rotor and align the outboard pad upper edge with the caliper slide abutment. Rotate the lower end of the caliper into position Caliper guide pin bolts and tighten to 200 inch lbs. (23 Nm) Banjo bolt with new washers on each side of the hose fitting and tighten to 35 ft. lbs. (47 Nm) Wheels Negative battery cable
   
5. Bleed the brake system and road test the vehicle

we had replaced the engine in our 87 4.3 star craft and when we put the omc cobra stern drive back in we now dont have foward gear, we have nuetral and reverse. could it be the linkage or could it be the shifter cable or any other idea's that could be the problem.

Hi David:

First, check the fuses for the hydraulic motor; if they're blown, replace and monitor (why did they blow? Perhaps an overload, or ...) These fuses are located in the engine bay on top of the fender by the front right wheel housing.

Next check the voltage supply to the top switch, possibly a loose connection or broken wire.

Also check relays C (raising top) and D (lowering top) under the rear seat.

Lastly check for voltage at the pump, also under the rear seat, when the switch is actuated, and that the voltage polarity reverses when the switch is actuated the other way (up or down).

After that, it's a hydraulic/mechanical problem. Check the fluid level in the pump reservoir (use SAAB fluid to top up if low) Fluid level should be at the upper marker with top down, and at the lower marker with top up.

Check behind the rear seat side panels that the piston shaft is still properly attached to the roof mechanism bracket at one end, and the piston itself is still firmly attached to the body. Look for any leakage from the system.

If all tests out OK and looks good under the rear seat and behind the side panels, then there is the possibility that the piston seals have failed and the fluid is just circulating around without activating the piston. Pistons are available (http://www.convertibletopguys.com/cgi-local/displaycat.cgi?cat=584 - scroll down) but the entire system should be removed to avoid getting hydraulic fluid on the interior.

However, that fact that you can operate the hood using the bypass valve (manually) would indicate that the hydraulics are likely OK, and that it's probably an electrical or mechanical problem.

Good luck!

Saabreur

There are 2 potential problems -
1. Leaking spool on the control valve - rebuild the vale.

2. Cylinder blow-by. Disassemble piston and replace the seals.

To test if its the cylinder - retract the cylinders all the way... remove the hoses on the blind end (non rod end) of each cylinder, and again pull the valve to the retract position.

If fluid continues to pour out of the cylinder - the piston seal is damaged, and the affected cylinder must be repaired.

To test if the valve spool is faulty - disconnect the a and b ports just after the valve. Turn on the system and check for seepage from the disconnected lines (without moving the lever).

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