What would cause this failure?

[rucaradio]

First its a VP AQ131D.

Murphy's Law was in full effect for me yesterday. I decided to take mom fishing for Mother's Day. Weather was terrible as the wind was 30+ mph with waves 3 1/2 feet on the lake. We found a sheltered cove, casted our lines, fished for a bit and decided to move.

In the MIDDLE of the lake I noticed the temp gauge started rising. When it got up past 210 I shut her down. Popped the cap off the strainer and steam bubbled out.

Thinking that my sea water pump crosspiece failed (just did a sea water pump rebuild a MONTH ago), I fished out my tool kit and removed the pump.

As I was taking the pump off, the center hub of the pump cover (number 3 in the picture) popped out from being worn. Since the cover failed, it allowed the impeller shaft to walk out of the crosspiece, effectively shutting down the impeller altogether.

Using my dad to put pressure on the tip of the shaft with an allen wrench I had I was able to limp back to the docks.

I happen to have another cover in the garage (bought a used sea pump last year off eBay). My question tho - is this a normal failure for this VP part? How can I ensure this doesn't happen again?

 

[airdvr1227]

Re: What would cause this failure?

You went out yesterday?...I'm impressed.

 

[Howard Sterndrive]

Re: What would cause this failure?

nice save too - glad you were watching the gages

 

[Don S]

Re: What would cause this failure?

My question tho - is this a normal failure for this VP part?

No, it's not a normal or common failure.

How can I ensure this doesn't happen again?

You can't

 

[rucaradio]

Re: What would cause this failure?

Yes I went out yesterday. I'm sick of crappy Ohio weekend weather! Lol.

And I always try to be prepared on the water. I bought a cheap metric toolset from Autozone for exactly situations like this.

Don S, is it just wear over time of the soft brass that the cover is made of or is it caused by something else? Is there supposed to be something other than the cover that keeps the impeller shaft from walking off the crosspiece?

 

[Don S]

Re: What would cause this failure?

Don S, is it just wear over time of the soft brass that the cover is made of or is it caused by something else? Is there supposed to be something other than the cover that keeps the impeller shaft from walking off the crosspiece?

I have no idea what caused it, I can't see it. Maybe your cross piece is bad and causing the shaft to push against the cover harder than normal.

 

[rucaradio]

Re: What would cause this failure?

The weather finally broke today, so I climbed in the boat and removed the sea water pump and the timing cover. Pic 1 shows the shaft, the piece that wore out of the center, the cover, then the crosspiece. Pic 2 shows the extremely worn crosspiece (which was just changed about 15 hours ago). I have another shaft and new crosspiece. Going to read up in the shop manual to see if I installed anything incorrectly 2 months ago. I'm racking my brain trying to figure out 1) What caused this failure and 2) how to keep it from happening again.

 

[CharlieB]

Re: What would cause this failure?

I'd like to see the end of the shaft that fit AGAINST the crosspiece.

It looks like the shaft and crosspiece did NOT fit together into the slot, the shaft butted against the crosspiece causing the shaft to thrust against the cover, wearing into the cover, and wearing the bar on the crosspiece.

I suspect you will see matching wear on the end of the shaft.

You are fortunate that the pump turned as long as it did.

 

[Don S]

Re: What would cause this failure?

As I recall, the cross piece does have that low section built in on one side. it should be facing the pump. If not, then the shaft would be forced againt the cover and would wear it out in a hurry.
When you install the pump, it should fit solidly up againt the timing cover without force. If you had to tighten the bolts to get it tight, then the cross piece was in backwards.

 

[rucaradio]

Re: What would cause this failure?

The impeller shaft is fine - no wear at either end. The crosspiece was installed dipped end facing the pump. Looking at the Volvo shop manual it appears the flat side needs to be facing the front, but the directions (and pictures really) are unclear. My Clymer's manual is just as vague.

The timing cover was missing its bottom right bolt. Don't know if that would cause the crosspiece to walk out of its boss in the intermediate shaft pulley.

Got it all put together and running with no issues tonight in the driveway, but as I was wrapping up I tried to reconnect the sea water hose from the transom shield to the copper pipe and the manifold at the sea water pump started leaking - what a pain that is.. I'm so tempted to cut the copper tubing in the middle and replace it with hose. Ugh. Frustration!

 

[captmello]

Re: What would cause this failure?

Hope you got the pump fixed.

You didn't think you were just going to jump in and go this year did you???

Good luck!