Raw water intake hose

[thomasalva]

I recently purchased a 1989 Cobalt 21BR with a Volvo Penta AQ271C and a duoprop outdrive (DP-A I believe). I've been going through it trying to determine condition as well as to learn how everything works. We've taken it out a couple of times (less than 30 minutes each time) just to practice and to hear it run.

Everything seems pretty good, and it runs very well. It's a little bit hard starting when cold, but fine after that. I haven't changed the fuel filter yet, but I'm wondering if the fuel pump might be getting weak.

My main question for now though is about replacing the raw water intake hose. The engine runs cool on the lake, but I started it for a couple of minutes last week at home with the outdrive submerged in a big rubber tub. I noticed that no water was coming out the exhaust so I killed the engine. I can hear water inside the raw water pump when I squeeze the hoses, so the impeller probably had enough water for lubrication, but I've already bought another impeller since I had planned to replace it anyway (preventative maintenance).

The exhaust and U-joint bellows were both replaced just before I bought the boat, but the raw water hose connected to the outdrive looks pretty bad and I suspect it may be leaking. It seems like this could have been preventing pickup from the water tub, but I would like some confirmation of this. I'm pretty sure this hose must be below the water line when on the lake, so I suppose the pump is still able to do it's job.

Regardless, I would like to replace this hose, but I'm not sure how to get to it. I've found a couple of manuals online, but I haven't found much help. Does the outdrive have to be removed? I can see the hose going into the transom, but in the engine compartment there is a just some sort of a junction box where the inboard hose connects. The outdrive manual has a procedure for "removing the sterndrive", and it shows removing the trim cylinder pin and lifting the outdrive. The next step is disconnecting the exhaust bellows and then removing the raw water hose. Looks like the shift cable also has to be removed, but I'm not sure if that's necessary just to replace the hose. It doesn't mention the transom end of the hose, and looking at the drive itself is a lot more intimidating than looking at drawings. This is all very new to me, and I'm really just guessing about how to proceed. I would very much appreciate any help anyone can provide.

Thanks,
Shawn

 

[captmello]

Re: Raw water intake hose

Welcome to Iboats. Nice to see I'm not the only one working on their Volvo outdrive today.

I have not worked on your outdrive, however it is similar to mine. The manuals give little to no info on service like that hose. You just have to figure it out. Can it come off without removing the drive? Thats up to you.

I have had the hose off and replaced the fitting that the hose attach's at the drive on my outdrive without removing the drive. Those fittings, looks like an old style auto thermostat cover only miniature, are a typical trouble spot for the old VP's. They corrode under the hose. If you get the hose off you will see if its bad or not. When they go bad, they allow the system to suck air and cause overheat issues.

Good luck to you and let us know how it goes.

 

[Maclin]

Re: Raw water intake hose

The fitting that the raw water hose connects to corrodes away over time with these, so you need both items. All of that is underwater in the lake at idle and slow speeds so it does not matter if they leak or not, but will cause problems on plane if the hose or fitting allows air in.

The entire drive does not need to be removed, just the upper gear case. The u-joint bellows is also replaced this way. The u-joints can be serviced as well because the drive shaft will come off with the upper gear case.

The raw water fitting is easily accessed once the upper gear case is removed.

The raw water hose is formed and must be pushed thru the transom from the inside. The fitting inside at the transom is hard to get to but I did it and I am fighting off arthritis, had to use a swivel joint and extensions to get at the two small bolts.


I think I have described this before in earlier posts. Basically the helmet bolts are removed and the helmet moved up, the gear shift cable clamp is loosened so it can be slipped out once the cable end is disconnected. The ujoint bellows is unclamped at the drive. The bolts and nuts are removed (there are 2 studs with nuts and two longer bolts) and the upper unit worked off of the drive and the bell housing inside the transom. You can then unclamp the other end of the drive bellows if it is to be removed. I was replacing the drive bellows and u-joints and the raw water fitting and hose when I did this to mine.

I used a combination of a Seloc manual and web searches and planned mine for a long time first before I learned the drive does not have to come off. The Seloc manual does give an ok step by step of how to remove the upper housing. It is part of another procedure in there so you kind of have to pick out the steps you need. As always the factory manuals are better. I think the Volvo manuals are downloadable from the "Adults Only" sectiion at the top of this forum.

My drive seals at the gear housing where the u-joint yoke is were ok. My u-joints were rusty as my bellows had a tear in it, There was no evidence of oil in the bellows area. If you see milky nasty drive fluid and/or water mix in the drive bellows area that means drive oil is coming out of the drive and into the bellows. A watery milky mix means the bellows was leaking and you probably got water into the drive from the bellows area. If your drive bellows was letting water in that can also affect the bearings inside the bellhousing.

Good luck with your boat. I really like my AQ271C and DPA drive, really runs great.

 

[thomasalva]

Re: Raw water intake hose

Thanks for your replies. It's supposed to rain all weekend, so I'll try and at least plan the hose and fitting replacement this weekend. Do you know of a good source for parts? I can order them from a semi-local marina in my area, but it would be nice to find an online source.

Maclin, sorry for the ignorance, but I don't quite understand how the upper gear case can be removed by itself. When the upper connections are removed, can the entire unit pivot downward? Looking at the Volvo manual I guess that would mean the trim cylinder pin is left in place. If that's the deal, then the job doesn't look too bad. Sounds like the hardest part will be disconnecting the inboard side of the hose and then getting the new one pushed back through.

I'm sure it will make more sense once I get into it. I don't have a Seloc manual, so I should probably start by getting that.

Thanks again,
Shawn

 

[Maclin]

Re: Raw water intake hose

The drive will be all the way down. The driveshaft does not go into the splines very far inside the bellhousing and the top gear shaft is also a shallow fit into the intermediate housing shaft splines, and that allows enough wiggle room that when you pry up on a front corner of the upper housing you can work it out. It was pretty wierd to me, I was just doing on faith what the book and others had said, and lo and behold it came right out like a 25 pound baby right into my hands. Be ready, it is heavy for the size and unwieldy and will be slick with oil on some surfaces.

 

[thomasalva]

Re: Raw water intake hose

Ahhh, after looking more closely at some drawings, I think I realize the source of confusion. I was picturing the "upper unit" as including the "intermediate housing". I see now the outdrive is actually three parts, and the upper gear case you are referring to is just the small unit at the top which unbolts from the intermediate housing. I won't pull it until I have the replacement parts in hand, but this looks pretty straight-forward. I can see that if the upper unit is pulled off, everything behind it will be relatively easy to reach. If I can just get a hold of the parts now I think I'll be in business.

I appreciate your help on this.