Diagnose Cause of Hydraulic Steering Failure 2005 VERADO 225

[tothemax]

Give me advice on finding and repairing the cause of a failure of the hydraulic steering on a 2005 Mercury VERADO 225-HO engine, based on my narrative below.

I have experience with hydraulic steering systems, but not with the VERADO power-assisted steering system. At some time in the past [when there was a loss of power-assisted steering the cause was] the [the 12-Volt 40-Ampere] circuit breaker [that powers the electric motor in the boost pump] was tripped open. When that occurred the boat began to steer "like a Mac truck" but at least there was steering. The remedy for that problem was to reset the tripped circuit breaker.

On Sunday, August 25, 2024 the my [c.2005] 220 DAUNTLESS boat with a 2005 VERADO 225-HP engine was underway for about 30-minutes, and then the hydraulic steering became unresponsive, as if the system were full of air. I checked the [40-Ampere] circuit breaker; it was not tripped open. In this instance the VERADO power-assisted steering very quickly went from very sloppy, to requiring twenty turns of the wheel to get a bit of actual engine movement, to no movement of the engine at all no matter how many turns of the wheel. This behavior felt like a hydraulic line was broken.

I only did a visual inspection of the accessible steering components:

• the [helm pump] behind the steering wheel;
• the hose connections behind the console;
• the connections at the [steering ram actuator] on the engine; and
• the lines coming through the deck from the boost pump to the engine steering actuator.

I did not take off the cover of the [hydraulic boost] pump unit.There was [no sign or indication of leaking hydraulic fluid] anywhere. I have yet to remove the cover on the electro-hydraulic boost pump.

At this point time was getting late. My neighbor was on his [boat and on his] way home, and gave me a tow to the dock.

MORE HISTORY
A week ago the boat was in the shop. The starboard hydraulic actuator [of the dual actuator power-trim-and-tilt system] was was rebuilt. The boat steering was working when I left the shop on Thursday, August 22, 2024. [That trim-tilt actuator] is the same general area [as the hydraulic steering actuator] but to my mind the [steering and trim-tilt] systems are not related.

After paying for the [service charges] from [the trim-tilt system] repair, I think I'll tackle [trying to diagnose and remedy this new power-assist steering problem] myself.

I bought this 220 DAUNTLESS in the summer of 2023. It had been sitting on a lift for many years with almost no use until I purchased it. We purchased the boat from a family member who had bought it as a new boat, and who was not boat savvy, The running time then as only 79-hours. It had been sitting for about three years. We did all the basic maintenance last year. I hired the dealer to run diagnostics on the VERAOD engine: everything checked out fine. Since 2006 this boat has probably sat on a boat lift--for about 18 years. I think we are working out the bugs from sitting idle for so long.

I will appreciate any feedback [on finding the cause of the steering system failure and how to remedy that problem].

[jimh]

Typically the hydraulic actuator ram for outboard engine steering would have bleed fittings at the point where the lines from the helm pump (or in this case from the boost pump) connect to the actuator. If there are such fitting, check to see if they are shut and tight.

If one of the bleed fittings was loose, the steering system could have pumped hydraulic fluid out of the system and overboard to the sea during your 30-minute trip you reported in your narrative. That existence of the boost pump may have accelerated the rate at which hydraulic fluid was able to displaced from the system via the loose bleed valve. There could be evidence of some hydraulic fluid around the bleed valve if the loss of fluid occurred there. Note that hydraulic fluid has almost no viscosity and it loves to flow in the direction favored by gravity when it leaks out of the steering system, and it could flow for a long distance.

If the fittings were shut and tight, you could open one fitting slightly and then turn the helm steering wheel. If there is hydraulic fluid being pumped to the engine actuator, you should see the hydraulic fluid escaping from the bleed valve. Try turning the wheel in both directions. Don't allow more than a very small volume of fluid to escape during the test, if any fluid does escape at all. If there is no sign of hydraulic fluid at the actuator bleed valve, you have probably found the cause of the steering being unresponsive to input from the helm pump.

[tothemax]

Clarifications: [all these clarifications have been implemented in the original article to make the thread more easy to understand at the first reading.--Moderator]

Thanks for the quick response. I'm going to dig into the manuals today.

[Jefecinco]

A very common problem with that steering system is overheating. Several users have been able to eliminate the problem by increasing the length of the fluid return hose. If lengthening the hose is of any interest a search of YouTube videos may be useful.

[jimh]

Re finding something on youTube:

The presentation on youTube at

Mercury Power Steering Problems
https://www.youtube.com/watch?v=bQS8XKU4-FM

suggests that the engine-mounted steering actuator on the early generation VERADO engines are prone to failure. I think a c.2005 VERADO would be the early generation version.

The presentation also demonstrates how a small electrical jumper (possibly called a "signal driver") could be the cause of the the steering boost pump to not operate.

Curiously, it shows the boost pump electrical circuit over-current protection as a 40-Ampere fuse, not a circuit-breaker as reported above in the initial narrative of the problem. That may be because the installation is not on a Boston Whaler boat.

This same presenter has other episodes related to Mercury power steering failures.

[tothemax]

The follow-up [comments] are really appreciated.

By Thursday, August 29, 2024 I may have time to try to diagnose the case of the steering system failure on the 2005 Mercury VERADO 225-HP engine.

I cannot imagine that if there were a leak I would not have seem some hydraulic fluid somewhere around the engine or the steering engine-steering-ram actuator or in the boat sump spaces. However, the steering boost pump is contained in a housing, so a leak there might be contained and concealed.

The Boston Whaler drawings show that the circuit breaker [for electrical power to the boost pump motor] is a thermal 50-Ampere circuit breaker, and part number for Boston Whaler is 1475441. When I've lost the power assist in the past checking [this circuit breaker had tripped open] and resetting the circuit breaker resolved the loss of power steering.

The Mercury power steering pump shown in Figure 1 below looks very similar to the Mercury power steering pump that is on my [c.2005] 220 DAUNTLESS.

Fig. 1. A Mercury power steering pump that has a similar appearance to the pump in the boat in this discussion. The cover has been removed in this view.

mercuryPowerSterring.jpg (39.86 KiB) Viewed 21844 times

[jimh]

ROGER ON:

• you won't have time in investigate further until perhaps August 29, 2024
• the circuit breaker might be 50-Amperes instead of 40-Amperes; usually the rating is right on the circuit breaker itself, often on the toggle, and that is more definitive than what is listed on a part breakdown drawing;
• your impression remains that the steering system acted on your last outing with the boat like there was air in the hydraulic system or the fluid level in the hydraulic system is low, as you mentioned in your initial narrative of the problem and in other comments.

According to the presentation on youTube (that I linked earlier) when the system is operating properly, the power steering pump should begin to run as soon as the engine is started, and the pump motor makes an audible noise that can be heard when near to the pump, particularly if you have removed the plastic cover.

[jimh]

A very common problem with that steering system is overheating.

With the electrical motor and hydraulic pump enclosed in a housing without any ventilation (which was probably done to reduce transmission of noise from the motor and pump to the boat occupants) I can see how an electrical motor that apparently runs continuously whenever the engine ignition switch is in the RUN position and is in a climate with high ambient air temperature might be prone to problems with temperature rise greater than anticipated by the company that made the motor and leading to a shorter service life than expected.

You cannot have a sound-proof enclosure and then also have cooling air flow inside the enclosure without very elaborate ducting.

[tothemax]

The presentation on youTube at

Mercury Power Steering Problems
https://www.youtube.com/watch?v=bQS8XKU4-FM

suggests that the engine-mounted steering actuator on the early generation VERADO engines are prone to failure. I think a c.2005 VERADO would be the early generation version.

My 2005 VERADO 255-HP has the second-generation hydraulic steering actuator, and that is probably a good thing.

I wish the Mercury power steering pump on my boat was as accessible as [the pump seen in the youTube episode linked above].

At 3:20 in the presentation the service technician tries the steering wheel with the engine not running. That engine actually moves. On my boat when the steering wheel is moved the engine does not move. The steering wheel can be turned and turned and there is never any build up of [resistance to turning or creation of] pressure [in the hydraulic steering system].

I have not found any on-line presentation [about steering failure on a VERADO engine] that matches my situation.

Before I can worry about the power steering boost pump, I need to discover why the helm steering pump is not creating any pressure. One explanation may be a check valve is stuck in a open position, and the hydraulic fluid is just bypassing.

I will follow-up after I have done more diagnosis of the cause of the problem of the failed steering on the 2005 VERADO 225.

ASIDE: I stopped at my local West Marine store today to buy hydraulic fluid, but they did not have the recommended 0W-30 fluid. I will probably order it on Amazon so I can have some on hand.

[jimh]

The presentation on youTube at

Mercury Power Steering Problems
https://www.youtube.com/watch?v=bQS8XKU4-FM

suggests that the engine-mounted steering actuator on the early generation VERADO engines are prone to failure. I think a c.2005 VERADO would be the early generation version.

At 3:20 in the presentation the service technician tries the steering wheel with the engine not running. That engine actually moves. On my boat when the steering wheel is moved the engine does not move.

ROGER that the youTube presentation does not exactly match your situation. As my remarks noted, I mentioned the youTube presentation as the source of the comment that the engine-mounted hydraulic steering actuators were unreliable in the early VERADO engines.

The helm steering pump has to supply some pressure in the hydraulic lines to get any movement. That is why I recommended you open a bleed valve at the engine steering actuator--if there is a bleed valve there--and turn the steering wheel to see if there was a indication of any hydraulic fluid being expelled from the open bleed valve.

[jimh]

Your narrative reports previous occurrences when the 40-Ampere or perhaps 50-Ampere circuit breaker that protects the power distribution circuit to the Mercury power steering pump having tripped open. The breaker having tripped open in earlier use of the boat seems to me to be an indicator that there is some problem occurring in the Mercury power steering system. The circuit breaker rating of 40-Amperes or perhaps even 50-Amperes suggests that while the power consumption of the Mercury power steering electrical motor is quite large, the circuit breaker should have been selected so that in NORMAL operation of the Mercury power steering system the circuit breaker would never--or almost never--trip open due to excessive current flow.

You do not give an accounting of how often the 40-Ampere or perhaps 50-Ampere circuit breaker has tripped open while you were operating the boat--in what I here am assuming was a normal manner. If the Mercury power steering system were operating normally, that circuit breaker would not have tripped open. On that basis there may have been an existing problem in the Mercury power steering system, and this latest situation, loss of all steering control, may be just another evolutionary step in the manifestation of the defect that is causing the problem.

[tothemax]

Steering is working again

I visited the Mercury Verado owners group [apparently on Facebook--which means no one can see the resource unless they register for an account of that website and then "join" the group]. A "member" there responded [hmm-I think that means you must have been able to not only read the content of that group but you were authorized to post to that group] that they experienced the very same behavior.

On their boat [the cause of the loss of all hydraulic steering control on their Mercury VERADO engine] turned out to be [due to] a minor leak in a cylinder [perhaps means the steering actuator cylinder] which over a period of about one year caused a loss of hydraulic fluid in the system to the point where all steering control was lost.

[After reading about that cause] I removed the cover from Mercury power steering pump housing, [and apparently found the level of hydraulic fluid in the hydraulic fluid reservoir tank inside the housing to be low]. To restore the hydraulic fluid level in the reservoir tank to the FULL level, I had to add just a bit under two-quarts of hydraulic steering fluid to the tank.

The electric motor in the Mercury power steering pub only runs when the engine is running. As the hydraulic fluid level in the steering system "normalized" [apparently caused by the power steering pump motor running], the steering system response [to input at the steering wheel] started to return. Turning the steering wheel back and forth from lock-to-lock and while continuing to add more fluid to the reservoir in the power steering pump housing, brought the reservoir level back to almost FULL and resulted in the steering system have fairly decent response.

Of course it started raining, so I closed up for the day; the weather is still drizzly today. I may have to hold off until the next day before I can re-check and fully bleed out any air in the system.

The remaining question:

Q1: if the hydraulic power steering system on the Mercury VERDADO was down almost two quarts of hydraulic fluid, where did the missing fluid go?

I am still not seeing any visible fluid leakage around the steering system. The pump housing actually has a drain into the boat's sump area. The [steering actuator] cylinder unit is sealed where it attaches to the engine mount. My guess is that missing fluid may possibly be accumulating in the steering arm cavity.

I appreciate the comments and feedback. That the steering failed on the first boat trip after the boat had been in a shop for a repair of an unrelated problem must have been a weird coincidence.

I'll chalk [the failure of the Mercury power steering system due to low hydraulic fluid level to be an outcome due to] the years of sitting idle catching up with the boat.

Prior to launching the boat this year (2024) I did a number of maintenance tasks. I guess I skipped checking the fluid level in the Mercury power steering system. I have purchased two more quarts of hydraulic steering fluid to keep on board the boat.

Cheers

[jimh]

To hear you fixed the failure of the Mercury power steering on your VERADO engine by buying two quarts of hydraulic fluid is a great outcome. If you had taken the boat to a service dealer, they might have found a lot more things that were needed to provide a remedy to the problem than adding more fluid.

I am interested in your plan to bleed air from the system. Please describe how you will be doing that.

For a moment there your narrative (of adding fluid to the reservoir, then operating the steering wheel and seeing the reservoir level go down, then adding more fluid, then repeating until the reservoir level remained at almost FULL level) sounded like the power steering pump was going to somehow automatically bleed air from the system.

Q2: is the cap on the hydraulic fluid reservoir an air-tight seal?

I assume you were leaving the cap off while your were refilling, so maybe the air was venting out there. If that is so, perhaps the system will self-vent if you operate it with the cap off for long enough.

Re having spare hydraulic fluid on-board: I always carry spare hydraulic fluid on board if we are going to be going on any boat ride longer that a few minutes away from the dock. My steering system is from Teleflex, and the fluid they specify is not cheap--$30 per quart.

[jimh]

Re finding evidence of leaked hydraulic fluid:

Q3: what is the color of the hydraulic fluid used in your Mercury power steering system?

The fluid in my Teleflex system is clear (as gin) and its viscosity is so low that the fluid will flow for ten feet before it finds the lowest place it can reach and begin to puddle.

If the fluid on your boat drained into a sump area, and at some time the drain in that sump was open to the sea, the fluid is probably gone overboard. Or if the sump filled with water and a pump automatically (or manually) pumped it overboard, any hydraulic fluid in the sump might have gone overboard with the water.

I am unclear on your hypothesis that "missing fluid may possibly be accumulating in the steering arm cavity." Part of my confusion is I do not know what you mean by "steering arm cavity."

[jimh]

There is good information on TheHullTruth forum, and anyone can read it.

https://www.thehulltruth.com/boating-fo ... t-out.html

There is a comment that installations with white circuit breakers were earliest models. That would be consistent with a c.2005 VERADO.

The VERADO engine was most popular in its early days in south Florida. Up here in the Great Lakes I don’t think I actually saw a boat underway using a VERADO until about 2010.

[tothemax]

Today while I was bleeding [the steering system for my 2005 VERADO 225-HP engine] I found the leak where hydraulic fluid is leaking out of the steering system: the leak in the hydraulic [actuator] cylinder.

During bleeding the steering wheel would hit a hard stop [when turning] to Port, but it never got a firm or stop when turning to Starboard.

While working [the steering wheel] to bleed the in Starboard [direction] I heard a slight pop and saw oil on top of the [hydraulic steering actuator] cylinder, and the cause of the leak of hydraulic fluid appeared to be because an O-ring seal failed.

I was able to contain the oil very quickly, and very little oil got into the water.

My next step will be to figure out the cylinder repair. I hope that Mercury can provide a kit to repair the steering actuator cylinder because a new steering actuator cylinder costs about $3,500.

The early ( or so-called first-generation) VERADO steering systems have a cylinder with an external [drag] link or arm that connects to the engine [tiller] to steer the engine. A second-generation of VERADO steering has "internal" [steering], and aft of the [hydraulic actuator] steering cylinder there is an arm bolted to the top of the engine pivot shaft that is inside the engine mounting plate assembly.

Information of first and second generation VERADO steering can be found at
https://www.mercruiserparts.com/mercury-mercruiser-8m0123581-jpo-steerin

A parts diagram can be found at
https://www.mercruiserparts.com/bam/subassembly/32530/13604/200

[jimh]

If you can repair the leak in your VERADO Mercury power steering system by replacing a failed O-ring fastener, you will become the all-time expert on these problems. I wish you the best.

A problem you may encounter is how to disassemble the hydraulic steering actuator cylinder without causing any damage. I suspect that some specialized tool may be needed.

ASIDE: I recall (without any real certainty) that the steering actuators for the VERADO were made by ULTRAFLEX, an alternative source of hydraulic steering compared to the more widely hydraulic steering system made by TELEFLEX. If you end up needing a new hydraulic steering actuator cylinder, you MIGHT be able to get it from the actual manufacturer (ULTRAFLEX) at a lower price.

Also see an archived discussion about VERADO engines with Mercury power steering and the notion that the electric motor will be running continuously whenever the ignition key is in the RUN position:

Verado Power Steering
https://continuouswave.com/ubb/Forum3/HTML/015989.html

The article also has information on the proper procedure to bleed the system of air.