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Volvo Raw Water Pump Repair

Another informative and innovative fix from Sailbleu

- our Forum's mechanical expert

It's still dark and cold outside, so maybe I can share the info on how to repair a VP (MD22L) raw water pump that has been leaking for some time now.

This is the one. Picture from marinepartseurope.com

 

It's not the first time I had this problem, and up to now I could solve it by changing the shaft seal.

 

However, the problem of this kind of leak exceeds a seal replacement. First of all there is the damage that results from salt water dripping over a hot engine making a mess of the paint and creating rust everywhere. Then there is the damage on the pumps bearing that is not sufficiently protected from water swirling around the pumps shaft and entering the bearing. In no time the ball races are destroyed and the pump makes a hell of a noise.

 

VP tried to protect the bearing with an O ring dangling around the shaft, but no use. In my opinion this secondary cooling system is not well designed, and normal wear can/will cause enormous collateral damage. I've always wondered why these pumps don't have a collector to divert a possible leakflow. Sooner or later you get leak, things just wear down, nothing to do about that, and preventive annual maintenance - read replacing impeller, shaft seal, bearings and so on - can go only that far. Where do you stop ?! Let me share a common problem with these pumps, where in most cases - if you have it done by a professional - a complete new pump is installed.

 

Check the price: www.marinepartseurope.com

 

The reason why these pumps start - and after a while STAY leaking is not only because of wear of the seal, but also because of wear on the shaft itself. Remember, this pump transports salt, sandy and dirty water. Very abrasive in other words.

 

Shaft and seal

 

This pic explains the problem.

 

Notice the green and red arrow. The green arrow is necessary, this way the seal stays in place.

The red arrow shows where the seal-lip has made a track as the shaft rotates allowing (over time) the passage of water when its deep enough. A new seal won't help anymore.

 

So you need a new shaft. But,....MPE (marinepartseurope) doesn't sell the separate shaft, which I think is very naughty. Only a 700 Euro shakeout for new pump will get you out of the misery.

 

Here's where the cavalry comes riding in. A Speedi Sleeve.

VoilĂ , pardon my french.

 

The speedi sleeve is shown slightly slid (what a tongue twister ) over the shaft and next to it the alu pipe to bring the sleeve into position. Be gently, don't get overexcited because a correction afterwards will be tough. The upstanding edge hold the alu pipe and can be cut away once the sleeve is in the correct position.

Cut the edge and peel it off. The shaft is now like new and the sleeve is much harder than the shaft. I guess it might be possible to reposition the sleeve (be it difficult) so it can last a very long time.

 

Time to address the leak's fallout now.

Making a collector with drain (and hose) so the engine will be protected from further water damage. I also took this opportunity to clean, sand, degrease and repaint the rusty spots on the engine.

A self-made brass collector with drain should do the job.

Firmly attached (screwed) to the pump so no vibrations can cause detachment.

 

And the finishing touch, painting the lot.

 

When dry, the joint/gap between collector and pump was sealed with Tec7.

A new (homemade) pump cover (MPE price is about 60 Euro) was imminent due to abrasive wear of the impeller.

 

The repair has cost me 30 Euro for the sleeve. Bearings and seal not included, but that can be considered as normal maintenance is it not.

 

Sailbleu - SO40DS