Still not pulling water from drive

[vwbugman69]

Replaced impeller this spring because I found bits and pieces when I winterized.

I am having trouble getting the pump to pull any water from the drive. I initially thought it was because I was using muffs, but this afternoon I put it in the river and the same issue - no water.

3.0GSMEFS w/ SX-M Drive

I have tried the following:
- pulling the drive off to make sure the oring was intact - All good
- connecting the hose to the water pump inlet - All good
- Connecting the hose to the inlet line to backflush hose/ drive - All good
- Taping off drive inlets to check for any leaks while the hose is on the inlet hose - All good, except I noticed a small drip from the starboard side hole in the upper drive. I thought these were drain holes so I assumed no issues. (see pic)



I am out of ideas and am looking for next steps here.....

 

[jimmbo]

Re: Still not pulling water from drive

When you replaced the inpeller, did you check the pump housing to make sure none of the bits and pieces were clogging the pump holes. When my pump went bits and pieces, I had to dig the bit and pieces out of the pump, they wedged themselves in pretty good. Also, any chance you hooked the hoses up backward?

 

[Don S]

Re: Still not pulling water from drive

If you have run that new impeller several times and it's still not getting water, I would bet the impeller is shot again.
You also need to have a really good amount of water volume and pressure coming from your hose when on muffs. Or the hoses backwards as suggested above.

 

[vwbugman69]

Re: Still not pulling water from drive

When I replaced the impeller I also replaced the entire housing as the plastic/metal connections had become loose.

I will try replacing the impeller again and see if there is a change.

 

[vwbugman69]

Re: Still not pulling water from drive

I expected to see an absolutely shredded impeller, but to me it looks perfect. Nothing is missing and it snapped back almost instantaneously. The only oddity I noticed was the cap was just laying in the housing instead of being on the impeller. Could this be an issue?



The river test will have to wait until tomorrow, but I am very skiddish on just burning through impellers trying to get to the root cause.

 

[Don S]

Re: Still not pulling water from drive

The cap being there isn't an issue, except for WHY is it there.

Do you still have the original impeller? Check to see if the new impeller is the same height (not diameter) as the old impeller.

 

[vwbugman69]

Re: Still not pulling water from drive

I don't have the original, but when I installed the new impeller this afternoon the height of the impeller matched a ridge in the housing. I did not compare that one to the one I took out, however.

Do you know was height is supposed to be in there? The one I took out measured 1.26" in height.

 

[Don S]

Re: Still not pulling water from drive

I have no idea what the height is. Are you using OEM impellers or aftermarket?

 

[vwbugman69]

Re: Still not pulling water from drive

Oem

 

[vwbugman69]

Re: Still not pulling water from drive

Well, no go on the muffs again tonight - Nothing is reaching the pump. I am, however, am doubting myself on the muffs as I can not get a good seal to the drive and it is spraying water all over..

Question - While in the river, I took the inlet hose off the pump and would have expected water to come pouring in since it is at/below the waterline, however, there was not even a drop. Does this mean there is a blockage somewhere? I have backflushed the drive and water flows with no issues.

I am at a complete loss here. What next?

 

[vwbugman69]

Re: Still not pulling water from drive

Narrowed down the problem a bit - I did the bucket test and pulled absolutely no water. What steps do I take now knowing that the impeller and housing are brand new?

 

[vwbugman69]

Re: Still not pulling water from drive

Swapped out the impeller again to see if it was shredded - It is wasn't, so I reran the bucket test with a clear hose. I noticed the pump would pull water up the hose, but just shy of the inlet, so I tightened the hose clamp and wala - pumpage.

I then threw the muffs on and when I held the muffs tight to the drive, I saw water coming out of the pivot housing area/ prop.

All was well I thought, so I brought it to the river again, but alas - NOTHING.

I am so confused on this and do not know what the problem could be or what to look at next. Ideas anyone?

 

[Lou C]

Re: Still not pulling water from drive

Do know if there is a blockage between the impeller and the drive? I'd take off the drive again, disconnect the hose from the transom to the impeller and back flush it, look to see if any old impeller pieces or anything else came out. What year drive is this? the SX or the newere style? I know on the SX series there is a clean out that you can remove to verify that water can flow from the drive to the hose that feeds the impeller.
When I change an impeller on my Cobra, I make sure that water flows up the drive to the housing and then I back flush the line from the thermo housing to the transom mount. That way you know you have water in and water out. The Volvo is a bit different with the impeller on the engine and if there are any air leaks in the line from the drive to the impeller, it's going to be hard for it to suck water that distance. In some ways the Alpha/Cobra/outboard concept of the impeller in the drive is better because it only has to suck the water form the bottom of the drive to the top, the rest of the way it pushes in, the Volvo/Bravo design it has to suck it in the whole way and any air leaks or obstructions or wear in the impeller housing will keep it from sucking in the water.

Edit: looks like you did back flush it, but are there any obstructions, like in the PS cooler (if you have one). The clear hose test in the water will tell you if it's sucking air.

 

[Don S]

Re: Still not pulling water from drive

Here is your next step.

http://www.4shared.com/file/50572185/e88f1d89/Volvo_Penta_Overheat_Diagnosis.html

 

[vwbugman69]

Re: Still not pulling water from drive

Looks like I will have to seperate the upper and lower and replace the water tube grommet I have been reading so much about.

I am putting my parts list together, so besides the oil passage o-ring and drive shaft retainer o-ring, will I need any additional parts such as the water tube retainer or grommet seal?

I know I will have to drain the gearcase oil, but does the entire drive to be removed from the boat or can I just drop the lower?

 

[Don S]

Re: Still not pulling water from drive

You can remove just the lower, but keep in mind you should be removing that drive yearly at least to grease the coupler splines and check the engine alignment, unless you want to figure out how to remove the engine.

Just look at the parts diagram. http://www.volvopentastore.com/Tran...on_id.845001004--store_id.366--view_id.782022

You need all the orings, seals, and gaskets where you take things apart.

 

[vwbugman69]

Re: Still not pulling water from drive

Thanks Don.

One thing is still bothering me though - If the drive is completely submerged and idling in water and if the water tube grommet is indeed bad, wouldn't it still suck water? Where is the air coming from?

 

[Don S]

Re: Still not pulling water from drive

If it's under water it wouldn't be sucking air, and if the complete outdrive is under water, then that is not where your air leak is.

 

[vwbugman69]

Re: Still not pulling water from drive

So the water tube grommet isn't the issue then.

What components are out of the water when idling and is there a way to pressure test the system to locate the leak? I have tried taping the pickups on the drive and hooking up a hose to the raw water pump inlet tube but didn't see any leaks. That points me to the raw water pump itself, but the impellar, housing, and o-ring are all new.

 

[Don S]

Re: Still not pulling water from drive

So the water tube grommet isn't the issue then.

Think about that question for a minute, if it's under water, how could it suck air?