Page 1 of 1

Verado power steering fluid mystery: where did it go?

Posted: Tue Apr 19, 2016 5:14 pm
by Foulweather Jack
The power steering pump on my Mercury Verado 250 failed last year and was replaced by the dealer.

Last weekend I started the process of getting the Conquest 235 out of mothballs and commissioned for the summer. I notice that when I turn on the engine, there is a mechanical whirring and stirring sound beneath the steering wheel, and when I check the fluid level in the power steering reservoir, it is quite low.

I'm quite certain that all I need to do is top of the steering fluid and I should be good to go, but where did the steering fluid go over the last year? I don't see any evidence of hydraulic fluid in the bilge, and it seems unlikely to me that it would simply evaporate, being contained in a sealed system.

Any ideas? Should I be concerned? Anything else to troubleshoot?

As always, I appreciate the sage advice on this forum.

ASIDE: I haven't visited since last year, so had to re-register to get onto the new forum. Jim, I like the new look!

Re: Verado power steering fluid mystery: where did it go?

Posted: Tue Apr 19, 2016 7:12 pm
by Jefecinco
Was the garboard drain plug removed during storage? If so, I imagine the fluid leaked onto the surface beneath the boat. It did not evaporate and it is not in the bilge so it must have leaked outside the boat.

I have no knowledge of the physical characteristics of Verado power steering fluid but unless it's quite different than ordinary automotive power steering fluid it very thin, often colorless and not very viscous. Several Verado owners have reported difficulty in locating leaks of the fluid. The leaks are usually finally located at the steering arm where it exits the steering ram or at one of the hose connections. Because the pump was recently replaced I would look at the hose connections at the pump first.

When the fluid is topped up you will probably be able to find the leak. Automotive stores may sell a dye that can be added to fluid to help locate leaks.

Re: Verado power steering fluid mystery: where did it go?

Posted: Fri Apr 22, 2016 8:05 am
by jimh
As JEFE' remarked, the hydraulic fluid used in hydraulic steering is very thin and will flow until it is only about one-molecule thick, so it will flow away from the source of the leak and go anywhere downhill from there.

From your narrative, it sounds like there is a leak in the hydraulic system. With power steering there are many additional connections. The front seal at the helm steering wheel is also a common source for leaks.

You should be very concerned. If the hydraulic fluid level is very low you could lose steering capability. That's not a good situation for a big boat with a 250-HP engine.

Re: Verado power steering fluid mystery: where did it go?

Posted: Fri Dec 13, 2019 7:51 am
by floater
[This three-year-old thread was revived by a spammer from India. The spammer just copied the original post and started the topic over again. The fake topic elicited a new reply. The spammer has been deleted. The real OP has never followed up with any further information about the VERADO steering fluid problem. I combined two replies made within a day or so that contained the same information--jimh]

Does your helm pump have the screw cap on top for filling it with fluid?

My original [helm pump] had a vent hole in the filler cap. I would lose fluid through that cap as the boat sat in the sun. I replaced the vented cap with a new cap with no hole, and the helm pump fluid remains constant now.

When I was looking for a replacement cap for my helm, Ultraflex recommended a solid cap over a vented one. I've been using the solid cap now for about three years and no problems.

Re: Verado power steering fluid mystery: where did it go?

Posted: Fri Dec 13, 2019 9:57 am
by Jefecinco
A system that is delivered with a vented cap is very likely to have been designed to be vented. A hydraulic system can become heated during use thus expanding the fluid and pressurizing the system. That can result in damage to the steering system seals and possibly other parts of the system.

The Verado engine owned by the OP is an L6 block. That engine installed on Boston Whaler boats is normally equipped with an electric power system pump and reservoir--if I recall correctly. It is likely that a leak in the electrical driven part of the system would end up in the bilge or below deck. Leaks in the helm pump or steering ram are usually very obvious as the leaking fluid will end up in the outboard well or in the console.

Any loss of fluid should be diagnosed and the cause corrected. Simply adding fluid can only delay an unwelcome problem.

On our purely hydraulic steering system a slight steering cylinder seal leak became more serious while we were boating. Controlling the boat was very difficult but we managed to get to a nearby marina where I could purchase some fluid. I had the parts and tools needed to top up and bleed the system so we were good. We headed for home, about ten miles away, and by the time we arrived we had lost so much fluid that we were barely able to maneuver into a slip. The seal was replaced before our next outing.

Re: Vented Filler Cap at Helm Pump

Posted: Fri Dec 13, 2019 10:05 am
by jimh
On the Teleflex hydraulic helm pump on my boat, I intentionally removed the fill port's sealed cap and replaced it with a vented cap on the recommendation of the factory engineer I spoke with. I think he even sent me the vented cap at no charge.

It is common to find the helm pump fluid level rises when the boat is sitting in strong sunlight and very hot weather. The proper level of fluid for the helm pump will be discovered after a few very hot days that have caused expansion and expelled the excess fluid via the vented cap. Once the proper level of fluid is reached, the leaking at the cap will stop.

I don't know if the rise in fluid level is due to expansion of the fluid or from some other mechanism. I would not expect hydraulic fluid to expand a great deal with temperature. Perhaps someone can comment on that. The rise in fluid might be more related to expansion of the flexible hoses, which could tend to reduce their inside diameters. There is a new discussion on that topic.

Another problem that can create confusion occurs if the actuator is a side-mount. The actuator's opposed cylinders are not symmetrical, and the volume of fluid that remains in the helm pump varies depending on which way the wheel is turned to its stop. The fluid level in the helm pump will rise at one direction of rotation, and drop at the other end. The volume of fluid has to be chosen to permit the higher-volume direction to not overflow the pump filler cap.

I am quite sure that in the VERADO power steering system that is the initial topic of inquiry, the cylinders are balanced and the fluid level in the helm pump won't vary with direction of rotation to end stop.

As I mentioned in my initial reply three-and-a-half years ago, hydraulic fluid loves to flow, and from the leak site the fluid can travel a long distance downhill until enough accumulates to get the attention of the boat operator.

Re: Verado power steering fluid mystery: where did it go?

Posted: Sun Jan 12, 2020 7:01 pm
by zigzag930

Verado PS fluid is very unique and can be hard to find. I live in Florida and called a dozen stores to find it this weekend.

BE SURE that you get 0W-30 FULL Synthetic fluid. Do not listen to the uniformed boat store people who will tell you that the regular Quicksilver PS fluid is fine for use in a Verado, it is NOT. I actually had two stores tell me they had it, only to get there and find out it was the wrong product. I actually had the last store text me a picture of the label on the bottle as I was getting PO'd that I was misled a few times.

The correct fluid will state 0W-30 Full synthetic right on the front of the bottle.