Volvo 280 impeller...

[AZ_Ron]

Hi all! So I've been tinkering with this 1972 trihull, and with muffs on the water intake, water is NOT being pumped up to the engine. It's been suggested that an impeller in the outdrive itself is bad, but in looking through the service manual, I can't seem to find a location for an impeller in the outdrive.
If anyone can give me an idea, I'd appreciate it.

Thanks!

Ron

 

[Don S]

Re: Volvo 280 impeller...

It's an engine mounted pump, Volvo has never had pumps in the drive.
Go here and download an owners manual for an AQ190

http://www.volvo.com/volvopenta/na/en-us/marineengines/pub_search/

 

[eddy pons]

Re: Volvo 280 impeller...

the impeller is located in a pump just above the crank, remove the 4 crews to access impeller,when replaced make sure it has enough sucktion at the pick up of the lower case,,,sometimes you need to plug the drain at the nose of the gear case because the pump will suck air in,,,also check the goose neck @ the outdrive end, if its corroded or broken it will do the same,, if all fails and everything appears good take the hose of the pick up pipe located behind the motor(chrome pipe) put your garden hose in the rubber hose and run the motor @ home to get all the bugs out that way,,,I found that not enough water preassure @ home affects the pick-up pump but in the water I had no problems,,,good luck,,,

 

[Scaaty]

Re: Volvo 280 impeller...

sometimes you need to plug the drain (actually an intake) at the nose of the gearcase

Yep. Get a 3/8ths bolt and a little duct tape on the threads..screw it in the nose hole to plug it up some. Then the muffs.
Of course, this AFTER you toss a new impeller in

 

[AZ_Ron]

Re: Volvo 280 impeller...

Hi guys. Thanks for the replies!
So the sea-water pump on the engine is designed to pull water all the way from the lower unit up to the engine? Is there a particular way I should check for a blockage from the lower unit to the pump?
I had the hose from the chrome pipe to the pump disconnected, and put muffs on the outdrive and didn't get any water from the pipe... Doesn't seem like there is enough room at the lower unit intake to get something in there large enough to block it. The hose to the pump is clear. This is why I was thinking there may be a pump in the outdrive to push the water up to the pump.
Should I hook my air compressor up to the chrome pipe and see if it'll blow out through the intake on the lower unit?? Just looking for ideas here. I have a replacement impeller for the sea-water pump. I'll pull it off later and see what the current one looks like. I have a pretty good suspicion it's burnt up though, as I couldn't get any water up to the engine using the muffs.

I know cars, but the cooling systems on boats are quite a bit different. Takes some getting used to!

Thanks!

Ron

 

[AZ_Ron]

Re: Volvo 280 impeller...

Where exactly is this drain at? Up at the sea-water pump on the engine, or back on the outdrive somewhere?

sometimes you need to plug the drain (actually an intake) at the nose of the gearcase

Yep. Get a 3/8ths bolt and a little duct tape on the threads..screw it in the nose hole to plug it up some. Then the muffs.
Of course, this AFTER you toss a new impeller in

 

[Scaaty]

Re: Volvo 280 impeller...

Where exactly is this drain at? Up at the sea-water pump on the engine, or back on the outdrive somewhere?

Couple inches in front of the lower unit oil drain plug...front of gearcase

 

[AZ_Ron]

Re: Volvo 280 impeller...

Thanks Scaaty... I was out tinkering this morning after I'd posted here and thought that was it. It seems if I try to seal up the muffs so the water doesn't leak around it, and plug the hole, water goes up through the pipe. With the muffs on, they leak too much to allow the water to go all the way up and feed the sea-water pump. I'm sure the impeller in the SW pump is thrashed. I'm going to swap it out, and then run the input hose to a bucket.

I think I've got it figured out though.

Thanks guys!

Ron

 

[AZ_Ron]

Re: Volvo 280 impeller...

Well, that was it... The impeller was wasted... the metal hub had broken free of the rubber, my guess is when it was run without water the other day when we were trying the muffs.
I don't see how a normal set of muffs could ever work on this... there's just too much getting around the cups.
Obviously, when the boats in the water, #1, the water doesn't really have to be pushed 'UP'... just forward, and #2, the pull from the prop forces water into the inlet.
Is there a 'proper' way to run the engine out of the water utilizing the intact cooling system (Pulling water from the outdrive) instead of pulling the water pumps hose off and sticking it in a bucket?
Aside from some kind of custom 'Super-Muff' that wouldn't have ANY leakage, and plugging the drain hole, I'm at a loss for another way of doing this. Yes, I'm new to boats...probably something really simple!

Ron

 

[Don S]

Re: Volvo 280 impeller...

If the impeller is good and there are no air leaks in the system up to the raw water pump, it will pull it up there with no problem.
When you put in the new impeller, lube it with some dishwashing liquid. It sure helps with the dry pump on muffs.
If you look at the water hose on the outside of the boat that goes from the inside of the boat to the drive, there is a hose connection where that hose hooks on to the outdrive. It's a known problem that that aluminum connection will corrode off right where the hose attaches and allow the pump to suck air (instead of water).
Don't just look at it, you need to push and pull the hose and see if it's solidly attached. Usually they will crumble if bad and you will pull the hose off.

One thing for sure, to change it or the hose you are going to need some factory service manuals. Not Seloc or Clymers. they won't help a bit.
See your local Volvo dealer for the manuals.

 

[Scaaty]

Re: Volvo 280 impeller...

Fer sure on what Don says, and also if you use the PROPER VP muffs, you don't even need to plug the front nose cone hole. I have took my intake pipe that runs under the manifold to the pump, and installed a "tee" and hose hook-up, so I can run a fresh water flush/Saltaway through it. I just (on the trailer when it comes out for the season) stick a 3/8ths bolt with a bit of tape on it to plug the front hole, and have a plug on the muffs too where you would do a water hose. I run from my flusher with ball valve then in the dog house ..