03 water pump recall strikes again ...

[obd666]

I have the same issue whenever I have drained all the water out of the system, i.e. after an impeller change or after dewinterization for the first time out of the year. The way I handle it is that I run the boat hooked to a waterhose in the drive way before I head to the lake for the first time. The water hose will put water in the system to prime it without the pump having to suck itself primed. Once the system is primed I never have trouble the rest of the season with the water pump not priming.

i had hoped this was the case with mine too. but when i setup the bucket i filled all the hoses with water before trying it, and it still wouldnt prime. i didn't however try it under pressure from the water hose, which may have helped it i guess. but, with the hoses full of water i feel like it should have been able to do it on its own ...

[LT206]

I have no basis to say this other than a hunch and personal experience, but I believe that all those hoses, once disconnected and reconnected are susceptable to air being sucked in at the clamp locations, no matter how tight you get the clamps, until the motor goes through a heat cycle to allow the rubber to "seal" itself around the fitting it is attached to. So even if you filled the hoses with water (and I'm sure you could not get them completely filled without some air left in them) you are still sucking enough air to keep the pump from priming.

[obd666]

I have no basis to say this other than a hunch and personal experience, but I believe that all those hoses, once disconnected and reconnected are susceptable to air being sucked in at the clamp locations, no matter how tight you get the clamps, until the motor goes through a heat cycle to allow the rubber to "seal" itself around the fitting it is attached to. So even if you filled the hoses with water (and I'm sure you could not get them completely filled without some air left in them) you are still sucking enough air to keep the pump from priming.

thats an interesting theory, and im certainly not discounting the possibility. but im not sure how you would validate it, since you would have to run the motor to heat it up and hope that you dont destroy the impeller while its not sucking water. i guess filling it with water beforehand buys you some time.

[DanielC]

On a Super Air, there is a lot of plumbing between the raw water pump, and the hull fitting. That means there is a lot of potential leaks for air in to the suction side of the cooling system, and a lot of hose to fill with water if it is empty. A lot of this plumbing is also above the water level in a floating boat. The fittings on the raw water strainer can get loose, and allow a tiny amount of air into the system, and this can allow the entire system to possibly drain if the boat is sitting for a while.

Here is a thread i did a few years ago, on a flushing adapter I made.
http://www.planetnautique.com/vb3/sh...light=flushing
This adapter allows you to pressurize the suction side of the raw water system. In most cases, the pressure will make even tiny air leaks obvious.

[LT206]

thats an interesting theory, and im certainly not discounting the possibility. but im not sure how you would validate it, since you would have to run the motor to heat it up and hope that you dont destroy the impeller while its not sucking water. i guess filling it with water beforehand buys you some time.

As I said, no basis other than experience. I've always gotten through by putting pressurized water to it the first time, never had the problem again.

[obd666]

On a Super Air, there is a lot of plumbing between the raw water pump, and the hull fitting. That means there is a lot of potential leaks for air in to the suction side of the cooling system, and a lot of hose to fill with water if it is empty. A lot of this plumbing is also above the water level in a floating boat. The fittings on the raw water strainer can get loose, and allow a tiny amount of air into the system, and this can allow the entire system to possibly drain if the boat is sitting for a while.

Here is a thread i did a few years ago, on a flushing adapter I made.
http://www.planetnautique.com/vb3/sh...light=flushing
This adapter allows you to pressurize the suction side of the raw water system. In most cases, the pressure will make even tiny air leaks obvious.

all good points. however, i isolated just the pump and filled the hoses with water. there was still some air in there i suppose, but i dont see how it wouldnt be able to overcome that ... i like that adapter, i have read that thread many times

[obd666]

As I said, no basis other than experience. I've always gotten through by putting pressurized water to it the first time, never had the problem again.

yeah, will prolly try that this afternoon. its just confusing because it has never not primed, after impeller changes or winterization ... clearly, there's a first time for everything

[DanielC]

It is my thought that the ability of a raw water pump to draw enough vacuum, moving only air, until the water get to is dependent in the very edges of the impeller being good. These same edges are the first thing damaged, running the pump dry, even briefly.

On a direct drive boat, the raw water pump is located in many cases below the water level when the boat is floating. And there is at the most, about 4 or 5 feet of plumbing between the water intake, and the raw water pump.

On a V-drive boat, goes through the raw water strainer, the V-drive, a transmission oil cooler, and lots of hoses to get to the raw water pump.

[obd666]

On a V-drive boat, goes through the raw water strainer, the V-drive, a transmission oil cooler, and lots of hoses to get to the raw water pump.

on my v-drive, it comes into the boat and hits the strainer and tranny cooler, then on to the pump. it hits the v-drive after that. i would estimate about 7-8 ft of hose before it hits the pump, which is much more than ideal for sure. my bucket test went directly into the tranny cooler bypassing the strainer, but was about the same length of hose. Am going to try again this afternoon ...

[TRDon]

I did do the bucket test later. I thought it was an impeller, and mine was shredded. I backflushed the motor, and got all the pieces out and installed the new impeller. It did nothing. It would suck up about 4 inches from the bucket and stop there. At that point I think I came on here and someone told me there was a recall. Sure enough, mine was a part of it.

As far as a test goes, I just make sure there is water in the hose going to the water pump and I start it in a bucket. I never run it on the hose being directly connected to the host that goes to the pump. Your boat water system is not pressurized on the lake, why would you use that as a valid test before puting it in. It will push past the water pump and cool the engine even if the impeller is missing. It just doesnt make sense to do it that way im my mind.

[DanielC]

I realize the suction side of the raw water pump is not pressurized on the lake. The reason I sometimes use pressure on this side of the raw water pump is that is is much easier to see water leaking out of the hoses and fittings, than it is to see air being sucked in to the plumbing.

[obd666]

after last nights round of tests, i feel certain its the pump ... ran my hose (big clear hose, not water hose) directly into the tranny cooler and filled up with water. holding the hose end up out of the bucket (leaving no gravity to overcome) is sucked the water right up. i kept feeding water into that hose with the water hose and the pump ran it through the motor fine, then exited the exhaust. should be primed at this point, but in the bucket it drew the water out 6 inches above the bucket then stopped. it just didnt have enough pull on it

[obd666]

and now, the rest of the story ... looks like PCM got away with one here, because the new pump sucked water up out of the bucket much faster than i could fill it. the recall listed pumps date coded thru AC and mine was ADA, which means my pump was the very next pump produced after the ones they found to be problematic - and just happened to exhibit the very same issues as the ones in the recall (won't prime). Even my engine serial number was cited as being affected. I would love to inform them that the pumps dated AD fail the same as the others, but i am reluctant to waste my time ... end of rant

so she is back to guzzling water, and we aim to make up for lost time this weekend points of note: the pumps are generally the same shape but the impeller fits tighter into the new ones housing. also, the new pumps use the O ring instead of the old paper gasket, which is definitely an upgrade.