1996 Four Winns Sundowner with 5.0 Cobra engine and drive

[Lou C]

Forgot to mention, what the pictograms on the drive are trying to communicate is do not remove the fill plug with the drive down or else you can get a shower in hydraulic fluid! tilt it up first. That's what I did after rebuilding my cyls and bleeding the system (5 up and 5 down cycles).

 

[Lpgc]

Hard to say why it’s bleeding down it could be either the cyls or the pump. If you rebuild the cyls & it still does it then it’s the pump seals. I rebuilt mine because one side was leaking and both of the alu end pieces that the rod goes thru were really corroded. Had to fix it. What I did was leave the old cyls on the boat & rebuilt them with a better set of used piston rods. Those are def the Cobra design cylinders; under the plastic top cover is a steel hydraulic line that goes to the end of the cyl. The later Volvo ones incorporated that into the body of the cyl so the design is a bit different. You can rebuild yours with the kit sold by BRP, here it’s about $55 USD per side.

I can buy rebuild kits for the SX rams but I haven't seen any for the Cobra rams. Don't think I've heard of BRP, could be a problem getting hold of the Cobra parts.

Is my pump (pictured above) standard SX?

I read that someone's rams didn't need servicing for 35 years, my rams don't look in bad condition, I can access the rams any time but if I refit trim in the boat (rear seats etc) it makes it difficult to access the pump. The pump squeels when the rams reach either extreme.. Based on all this it seems it makes sense to rebuild the pump first, then I can refit all the trim and still rebuild the rams if the problem doesn't go away?

I wonder if the rams need fixing if I could just take them to a hydraulics specialist to fix? Do the service kits just contain O rings or are there other parts?

 

[Lou C]

Bombardier
Recreational
Products
They are the company who bought OMC’s assets after the bankruptcy in 2000 and who still market OMC parts. Check Marineengine.com for parts…the kits have the orings needed for repair

 

[Lpgc]

I found this on Ebay, does it look like the correct parts to you? https://www.ebay.co.uk/itm/314922204566

 

[Lou C]

That looks like it
You have to compare the seals you took off to what’s in the kit because they usually include ones you don’t need

 

[Lpgc]

That looks like it
You have to compare the seals you took off to what’s in the kit because they usually include ones you don’t need

Thanks. I did a bit more reading and it seems lots of these rebuild kits are aftermarket with complaints about quality. Maybe they're all aftermarket if OMC no longer exists?

2 Rams so would I need 2 of these kits?

I might ask a hydraulics company like this https://www.pirtek.co.uk/services/hydraulic-cylinder-repair/ to fix my rams, do you think a firm like this might have correct size seals on the shelf?

 

[Lou C]

OMC original parts are readily availably here in the USA try marine engine.com, not sure if they ship to UK. A good hydraulic shop could do it but as long as you can get those end caps loose (pin wrench) & you have the right parts you can easily do it.

 

[Lou C]

 

[Lou C]

this is the kit I used
watch Michael Romer's you tube video on this

 

[Lpgc]

I emailed a marina to ask if they could supply a rebuild kit for my rams and pump (and sent them pictures of my rams and pump). This was their reply...

Hi Simon,
Im afraid the ram seal kits are the only item we can help with, we have no supply for the end caps required;
https://repowermarine.com/trim-ram-seal-kit-for-volvo-penta-sx-dp-sm-omc-cobra-repl-3854247.html

The parts they pointed me to do seem the same as those you pictured but that's got me confused because they're saying it's the same seal kit for a
Volvo Penta SX, DP-SM or OMC Cobra... If Volvo SX rams and OMC Cobra rams are a different design shouldn't they need different repair kits?

They didn't even mention the pump in their reply so I've emailed them again querying if the seals are correct (and do suit both SX and Cobra rams) and asking them about the pump.

Can you point me to a rebuild kit for my pump?

 

[Lou C]

https://www.marineengine.com/parts/omc-parts/omc-boat-parts.php?year=1996&hp=5.0&model=50FAPNCS&manufacturer=OMC+stern+drive&section=Power+Trim+%26amp%3B+Tilt

in this listing of parts item 65 is the cylinder rebuild kit
for the trim pump, I have never had to do one so I don't know what it is that wears on them. But some of the parts are available and even the whole pump is for like $1000 USD
The tilt n trim cyls were the same for the OMC Cobra and Volvo SX for the first few years of the Volvo SX run then at some point they changed the design, not sure if the internal parts are the same or different.
See if what your marina has is the same as item #65 on that list....

BRP part # 0985060

 

[Lou C]

Looked at it, might be the same thing with a different part #. There are basically 3 seals for the end cap and 1 oring and 2 split rings for the piston.

 

[Lpgc]

I looked at the link you sent, part #65 is 3854247 which does match the part number on my marina's website, so would you agree the marina I contacted has the correct kits to rebuild my rams?

I've been researching pump rebuild kits, knew I'd watched a Michael Romer video rebuilding the same pump as mine ages ago, found the same video and watched it again today. The pump rebuild kit is 3854397 but seems to be unavailable from anywhere.

I wonder if I removed and stripped my pump I might be able to re-use most of the old seals and find suitable replacement seals for any I find damaged? If the pump works but just allows fluid to cross from the lift side to the lower side (inside the pump) maybe I should just look at the check valve seals?

 

[Lpgc]

The pump rebuild kit is 3854397 but seems to be unavailable from anywhere.

Kit 3854397 just contains O rings, no hard parts. I looked at the Marineengine.com site and added all the O rings that kit 3854397 contains to 'my basket'. Some of the original parts are no longer made but in most cases there is an equivalent part that is available.

I compiled a list of part number in diagram, actual part number, equivalent part number, number of items in assembly, description and notes.

3 3852073 not needed fill port O ring
6 3852508 1 reservoir O ring
8 3852974 1 not needed filter
23 3852984 0914055 1 valve seat O ring
27 3852988 0914059 2 pump control O ring (1 IN STOCK)
28 3852989 0914060 1 valve core spring
29 3852990 0914061 1 trim up valve seat O ring
32 3856110 1 thermal relief O ring
37 3852166 0321163 1 motor to manifold O ring
38 3852982 0914053 1 NOT PART OF KIT (coupling between motor and pump)

Marineengine.com won't ship outside the US but my daughter in law (lives with my son near me in the UK) is from Lafeyette, Louisiana. If necessary I could get parts shipped to my daughter in law's aunt (whom I've met) and she could ship them to me but I'll try to find parts that can be shipped direct and preferably from a local source first.

It would be great to have the specs of all the O rings listed above.

The earlier pump seal kit (which 3854397 replaced) was 0508166, can't find any 0508166 either.

Back on the subject of the rams, I bought 2 x ram seal kits from the marina and a gland nut wrench tool (pin tool to disassemble the rams). Pirtek (the hydraulics company I mentioned above) don't rebuild rams but put me in touch with a local firm that does. The ram rebuild firm said they'd expect to rebuild my rams for under £200 and turnaround time might be 3 days, but costs could rise depending on what they found inside my rams and parts availability. They didn't fill me with confidence they'd get it done quickly or stick to the budget so I decided to rebuild the rams myself.

 

[Lou C]

If you do it your self there’s 2 things to get past:
1) end caps, these can be tough to get off, I used heat time & patience
2) removing the eyelet end that’s on the piston rod, this has to be done to replace 2 of the seals in the cap.
Micheal Romer covers both in his vid
I advise leaving the rams on the boat & not disconnecting the hydraulic lines as long as none of the hoses are leaking those hydraulic line fittings can be tough to get off too don’t want to bugger them up. Just check the inside of the rams for pitting and the rods as well I tilted them down dumped out the fluid and cleaned them with brake cleaner & compressed air. Doing it this way is faster & easier….

 

[Lpgc]

Thanks for the tips Lou.

I'd prefer to address the pump first because I can't access the pump with boat interior trim refitted but can access the rams, and I don't know if it's the pump/rams/both that need fixing.

That said, if I knew it was the rams at fault I could fix them with the parts I've already ordered. Not sure which way to proceed.

Do you know of anyone discussing pump O ring sizes? Thought maybe I could buy a few assorted O ring kits and hope they contained sizes that could replace any I find in my pump that are damaged.

This is what (pump repair kit) 3854397 contains, surely it can't be that difficult to find same size O rings to replace any I find that are damaged? Or are there other parts inside the pumps that go wrong? Heh I suppose if a different part (not an O ring) failed 3854397 wouldn't fix it anyway.



The filter is easily checked, if mine is OK (and I wouldn't expect a filter to fail, they can be washed out) then I don't need to worry about that. I doubt there's a problem with the bigger O rings. Everything else is just the little O rings.

 

[Horigan]

The pump squealing you hear at the trim limits is normal. It is the pump flow going through the pressure relief valves within the pump. The drive you have is a Cobra SX, and a Volvo SX-M. Same component part numbers.

I use this site for parts diagrams.
https://epc.brp.com/Index.aspx?lang=E&s1=77a840a1-954e-4381-aba1-84a6513a5bd3

Drill down through Evinrude, Stern Drive, year, etc.

 

[Lou C]

The pump I don’t know about, I’d search around here on the VP I/O forum, to see if people have had SX pumps apart & fixed them. I’m guessing the one you have is similar or the same as the one Volvo used on the SX series rather than the original OMC Cobra design. I have been able to get parts from Volvo that OMC no longer carries even though it is the same exact part and same part #. Like the 90* alu down pipes I needed for my exhaust conversion.

 

[Lpgc]

The pump squealing you hear at the trim limits is normal. It is the pump flow going through the pressure relief valves within the pump. The drive you have is a Cobra SX, and a Volvo SX-M. Same component part numbers.

I use this site for parts diagrams.
https://epc.brp.com/Index.aspx?lang=E&s1=77a840a1-954e-4381-aba1-84a6513a5bd3

Drill down through Evinrude, Stern Drive, year, etc.

Thanks, I've used lots of hydraulic equipment in the past (and we all have PAS on cars) and I can understand a bit of squealing but this sounds kind of half squeal half grating, I wondered if there was a problem with the connection between the motor and pump or some an internal problem with the pump. I would have expected the pitch of the sound the pump makes in operation to drop when the motor speed drops when the rams reach an extreme of travel, and it does, but there's also this harsh sound.

I clicked on your link and navigated to a parts diagram, it is almost the same diagram Lou linked to and another diagram I found, the diagrams have different numbers (e.g. 1>50) but the parts number listed for each diagram number is the same on all diagrams... I'm back to needing 3854397 with none in stock lol. The link below will take you to the page I landed on after entering my engine model number (or at least something close to my model number, correct engine, pump, drive, etc).

BRP Parts Catalogs

epc.brp.com

The pump I don’t know about, I’d search around here on the VP I/O forum, to see if people have had SX pumps apart & fixed them. I’m guessing the one you have is similar or the same as the one Volvo used on the SX series rather than the original OMC Cobra design. I have been able to get parts from Volvo that OMC no longer carries even though it is the same exact part and same part #. Like the 90* alu down pipes I needed for my exhaust conversion.

Seems that's what I'll have to do. Presuming I can't find a list of O ring sizes for the pump, if I decide to buy packs of various sized O rings should I buy sets of metric or imperial size Orings? I know that there's a problem with just comparing new to old O rings, the old O rings might have been a bigger or smaller size when new or at least before fitting, but I would at least expect to be able to find something very close to correct size.

Which O rings in the pump would most likely cause the problem of the drive falling?

Heh, there might even be a market for anyone who can put together a seal kit to replace 3854397, just explain that it doesn't contain the filter...

 

[Lou C]

On mine I get a slight squeal when coming to the stops but no grating sounds, and as old as it is, I never had problems with the drive drifting down after being trimmed up. So maybe you're on the right track. Why not look on the EU Volvo Penta parts site and see if they sell a rebuild kit for your year, remember it is the same as a Volvo SX.
The only reason why I had to get into this, was because one side was leaking, and both of the rear eyelets were corroded to a point where it could have caused a failure. Lucky I had a couple of pairs of good used cylinders, so I could get rid of the old pitted rams and the rotted rear eyelets.