Water in power steering reservoir Volvo penta D6 370 DPH

[GaryAH]

Hello. The power steering oil in the in the power steering reservoir for a Volvo Penta D6 370 DPH has emulsified due to water ingress, a visual inspection of the steering rams didn’t reveal anything obvious. Does anyone have any ideas as to the most likely cause of the problem. Cheers Gary.

 

[julians]

It's the steering rams, they're a known weak spot. New rams aren't hugely expensive any more.

 

[GaryAH]

Thanks Julian, I was just thinking if you get water in via the rams you might have expected to see some oil coming out or some pitting / corrosion but they look really clean. I’ve got an engineer coming to look on Monday so I guess he’ll confirm it’s the rams. Glad to hear they’re not as expensive as they used to be. Do you know how roughly how much they are these days. Cheers Gary.

 

[Portofino]

Any ram left extended under water will attract abrasive growth on the shiny smooth extended bit .
This abrasive then destroys the rubber ram seals and water ingress leads to emulsification.
You notice a rainbow film on the surface water at the stern if it’s pressured up as the oil leaks out .

Thats why it’s best to park a boat with the trim tabs up , nothing exposed .

How ever if the steering rams are under water usually a L + R then it’s impossible to protect both simultaneously.As when one side is closed the other is fully extended and exposed.Parked straight ahead both are 1/2 extended.

Would you want pressure on an outdrive set of the bellows for long periods anyhow If you did park them hard over ?

DPH leg is notorious for steering ram fails as a result.
Previous DPG on the KAD 300 has one ram located inside the transom , dry and out of the water and as result an uneventful ownership experience.

 

[Orthop]

Probably you have to change the steering ram regularly. I changed the ram after 4 years (bought the boat from new). Last season I had to fill up the oil at the steering wheel regularly, so we changed the ram during the winter period again.

 

[alt]

Thats why it’s best to park a boat with the trim tabs up , nothing exposed .

Previous DPG on the KAD 300 has one ram located inside the transom , dry and out of the water and as result an uneventful ownership experience.

And the out-drive fully trimmed down (also means no stress on the bellows).

As P mentioned, with the DP-G (And 290's etc) the steering ram is inside the boat, so not a concern.

Any time I see people with their out-drive trimmed out in our yard, my blood boils. I always advise them to leave the drive fully down and in center position so 1) no trim rams exposed and 2) no stress on the bellows.

 

[GaryAH]

Portofino thank you for your reply. I guess when I replace the rams I try and seal the gaiters that cover the piston rods as best as I can to try and prevent marine growth which may make the rams last a little bit longer.

 

[alt]

Portofino thank you for your reply. I guess when I replace the rams I try and seal the gaiters that cover the piston rods as best as I can to try and prevent marine growth which may make the rams last a little bit longer.

I think you can now buy gaitors / bellows for the steering rams?

 

[GaryAH]

Probably you have to change the steering ram regularly. I changed the ram after 4 years (bought the boat from new). Last season I had to fill up the oil at the steering wheel regularly, so we changed the ram during the winter period again.

Yep, agreed. The boat is 9 years old now and I only bought her late last season and couldn’t see them being replaced in the service history. I’m new to all this having previously had shaft driven boats.

 

[GaryAH]

And the out-drive fully trimmed down (also means no stress on the bellows).

As P mentioned, with the DP-G (And 290's etc) the steering ram is inside the boat, so not a concern.

Any time I see people with their out-drive trimmed out in our yard, my blood boils. I always advise them to leave the drive fully down and in center position so 1) no trim rams exposed and 2) no stress on the bellows.

Good to know having only had shaft driven boats before. She’s out of the water now for all those Winter jobs with the leg fully down and in the centre position

 

[GaryAH]

I think you can now buy gaitors / bellows for the steering rams?

Yes I think they come with them now - VP’s idea of trying to rectify the problem I guess....

 

[Sticky Fingers]

Yes I think they come with them now - VP’s idea of trying to rectify the problem I guess....

Yes that's right I think, my boat (new last year) has gaiters on the rams. DP-H legs. Not a brilliant pic but you can see it in this.

 

[mcanderson]

Thanks Julian, I was just thinking if you get water in via the rams you might have expected to see some oil coming out or some pitting / corrosion but they look really clean. I’ve got an engineer coming to look on Monday so I guess he’ll confirm it’s the rams. Glad to hear they’re not as expensive as they used to be. Do you know how roughly how much they are these days. Cheers Gary.

219 inc VAT from Key Part - Keypart

I have just bought two for my boat.

 

[spannerman]

Check the hydraulic hoses also, these have had 3 upgrades due to persistent failure, in fact Volvo have had endless problems with rams and hoses and trim cylinder hoses, lost count of how many I have replaced on recalls and under warranty. Also make sure the engineer flushes the entire system as the contaminated oil if left in the system can damage the shuttle valve mounted on the transom at the back of the engine and hard to get to, the piston rusts and then your helm steering doesn’t operate the valve which controls the pressurised oil from the servo pump.

 

[julians]

The rubber gaitors do increase the length of time between needing to replace the rams, but they dont eliminate the problem completely.

 

[simonfraser]

on most rams you can remove the end caps, remove the cylinders and replace the seals

 

[julians]

on most rams you can remove the end caps, remove the cylinders and replace the seals

There do seem to be rebuild kits available for the dph steering rams, but nobody seems to bother using them. Maybe because if you're paying someone to do the work the additional labour involved in rebuilding the ram is more than the cost of just buying a new ram? I dont know....

 

[simonfraser]

i did mine, only alternative was new rams for which the engine likely had to come out

main bit of fun was getting the caps off, pm me if you want further info

 

[julians]

i did mine, only alternative was new rams for which the engine likely had to come out

main bit of fun was getting the caps off, pm me if you want further info

That presumably wasnt on a dph drive? on a dph the rams are easily accessible because they're entirely outside the boat under the water

 

[simonfraser]

That presumably wasnt on a dph drive? on a dph the rams are easily accessible because they're entirely outside the boat under the water

sure the ram location varies, mine are DP-E