How to Bleed Trim and Tilt Mercruiser: Step-by-Step Guide

To bleed trim and tilt on a Mercruiser, use the tilt/trim pump bleed procedure outlined in the vessel’s owners manual.

How To Bleed Trim And Tilt Mercruiser

Bleeding trim and tilt Mercruiser boat motors is an important procedure to ensure the proper and safe operation of the motor. This method eliminates any trapped air in the hydraulic system that can prevent movement of the trim or tilt functions. It must be done as part of routine maintenance, especially if any fluid changes were made in the hydraulic system. The procedure is relatively straightforward, but should be carried out with care and caution for maximum safety.

The first step is to locate and properly identify the different lines leading from the trim/tilt motor and pump. In most cases, there should be a bleed screw at each connecting point. Next, locate a suitable container (such as a bucket) to catch any spilling fluid during this process. It’s important to use clean, fresh fluids that correspond with your Mercruiser boat motor type usually either Type F or Type A transmission fluid.

Once these preparatory steps are complete, two people are recommended for this task: one on the helm and one at the pump unit. The helm person is required to adjust both trim and tilt functions slightly while the pump person loosens each bleed screw until a small trickle of hydraulic fluid begins to drip out into their container (usually taking 10-20 seconds). Re-tighten these screws as they take turns continuing through all bleed screws ensuring no trapped air remains in the system. The process should take around ten minutes or so depending on your motor type depending on motor type before it’s complete . Finally, ensure all bleed screws are securely closed before restarting your engine and testing out your trim/tilt functions for proper operation once more.

Preparing to Bleed The Trim And Tilt System

Before starting the process of bleeding the Mercruiser trim and tilt system, it is essential to ensure that all the components necessary for the process are in good condition and are compatible with each other. Additionally, the right tools should be gathered so that they can be used while carrying out the procedure.

Understanding the Mercruiser Tilt And Trim System

The primary function of a Mercruiser tilt and trim system is to adjust the angle of a vessels outboard motor to provide better control in various water conditions. It does this by using hydraulic cylinders on either side of the motor which are connected by hoses that contain hydraulic fluid. The components that form part of this system include: rams, pistons, hoses, reservoirs, impellers, filters, valves and more.

Conduct a Pre-Bleed Test

It is important to conduct a pre-bleed test before starting the process. This involves checking for any air bubbles or leaks in the trim and tilt system which could impede performance during operation. To do this, start by switching off all power supplies related to the unit before turning off any valves or disconnecting any hoses. Then make sure that there is enough hydraulic fluid in the reservoir before closing all valves or reconnecting any hoses. Once everything has been checked, turn on all power supplies related to the unit and then start running it through its normal range of motion. After running through its range of motion twice take note of how it feels and sounds during operation as this will indicate whether there are any air bubbles or leaks present in the system.

Openingu The Internal Reservoirs For Bleeding

Once you have conducted a pre-bleed test with no signs of air bubbles or leaks present in the system you can begin opening up internal reservoirs for bleeding. Start by filling up your hydraulic fluid reservoir with an approved type of oil before locating your impellers inside your reservoir. Once located you can open their bleed screws to get rid of any trapped air bubbles inside them before continuing with opening up other internal reservoirs such as those found on ram cylinders and hose nipples for further bleeding purposes if needed.

Bleeding The Hoses And Cylinder Rams

To continue bleeding your hoses and cylinder rams attach a bleeder screw onto each one before opening them up one at a time starting from those closest to your hydraulic fluid reservoir first going down gradually until you have completed all bleeders present within your trim and tilt system. During this process make sure not to release too much pressure so as not to cause splattering or force fluids through too quickly as this could damage parts in your system if done improperly.

Checking For Suction Leaks And Climbing Action

When checking for suction leaks and climb action in a trim and tilt Mercruiser, it is important to fill all fluid reservoirs and monitor the climb action. This can be done by slowly raising the trim angle on the outboard motor and verifying that there is no decrease in suction or power. If a decrease is noticed, then there may be a suction leak somewhere in the system. It is also important to check for any leaks in the hoses or fittings that are connected to the trim system.

Testing The Mercruiser Tilt System Functionality

In order to test the tilt system functionality of a Mercruiser, it is important to lower and raise the trim angle on the outboard motor several times. This will ensure that all components of the trim system are working properly and that there are no obstructions preventing full range of motion. Additionally, it is also important to increase the trim range of motion by adjusting the trim limit switch if necessary.

Proper Maintenance Of Mercruiser Trim System Parts

Performing proper maintenance on Mercruiser trim system parts is essential for ensuring optimal performance. This includes replacing O-rings, hoses, seals, bearings and other components as needed. Additionally, it is important to inspect all components for signs of wear or damage that could potentially compromise performance or lead to premature failure.

Cleaning Components Of Trim And Tilt Systems

Cleaning components of trim and tilt systems is also an important part of proper maintenance. Before cleaning any valves, hoses or cylinders, it is important to gather all necessary cleaning materials such as degreaser and rags. Once all materials have been gathered, these components should be thoroughly inspected for rust or grime before beginning cleaning process. After cleaning has been completed, these parts should be re-inspected for proper installation before being put back into service.

FAQ & Answers

Q: What components do I need to check before bleeding the trim and tilt system?
A: Before bleeding the trim and tilt system, you should check all components of the Mercruiser tilt and trim system, including the functionality and components of the system.

Q: How do I conduct a pre-bleed test?
A: To conduct a pre-bleed test, you should first run a prior test to identify any issues that may exist. After doing so, you should then run an after test to ensure that any problems have been resolved.

Q: How do I open the internal reservoirs for bleeding?
A: To open the internal reservoirs for bleeding, you should first fill the hydraulic fluid reservoir. Once done, you should then locate the impellers in order to access the ram cylinders and hose nipples.

Q: How do I check for suction leaks and climbing action?
A: To check for suction leaks and climbing action, fill up the fluid reservoirs again and monitor the climb action of your Mercruiser tilt system. If there is any issue with either suction or climbing action, make necessary adjustments accordingly.

Q: What kind of maintenance should be done on Mercruiser trim system parts?
A: When it comes to proper maintenance of Mercruiser trim system parts, it is important that you replace O-rings and hoses regularly as well as inspect bearings and seals in order to keep them in good condition. Additionally, it is also important that you clean components such as valves, hoses and cylinders regularly in order to prevent rust or grime from building up.

In conclusion, bleeding trim and tilt on a Mercruiser is a relatively simple task that can be done in a few easy steps. The steps are to drain the reservoir, hook up a hose to the motor, run the motor in neutral until air stops coming out of the bleed hole, and check for correct operation of the trim and tilt. With proper maintenance and following these steps, your Mercruiser trim and tilt should be in top working condition.