Raw Water Pump Mounting Modification

Copper spacer in place ready for mounting

A while ago I replaced my raw water pump for my Westerbeke engine and discovered that the replacement pump had a flat foot for mounting that would not fit in the machined groove of it's mounting bracket. ( machined groove can be seen in last photo). The original pump had been machined to allow for this, but the replacement had not.

Temporary solution

What to do? A quick solution was to place two large flat washers on which would allow the pump to sit flat and square, as well as, being able to slide in and out as I adjust the belt for tension.
The washers were the ideal size, but a better solution was available with a little cooper stock.

Pump mounted

I could of had the pump sent out for machining so that the foot would fit the recessed groove, but instead I had a large flat copper bar made to the dimensions to fit the groove and two holes placed for the holding bolts. This can be seen in place on the photo to the left and placed over the bolts ready for mounting in the top photo.
This means now, that any Sherwood pump I buy to replace, now no longer needs machining to fit the mounting bracket.

Field Overhaul of Sherwood R10870G, R50G, R30G Raw Water Pump

I had replaced my raw water pump some years ago and I finally managed to get a pump repair kit. I didn't have a fancy workshop with press, but instead had to make do with the tools I had on the boat. Here is how I set about reviving this old raw water pump.
First I removed the four bolts holding the cover plate on and extracted the rubber impeller. You can remove the impeller by using  needle nose pliers, holding an impeller blade opposite each other. Gently pull, alternating sides till it slides out.
Then I moved to the pulley end and undid the two screws holding the bearing and seal body to the main body.

Once the bearing body and shaft has been removed, remove the seal assembly. This will necessitate removing a small circlip on the shaft. Now remove the two woodruff keys. I use a pair of side cutters and gently grip at the base of the woodruff key and lever up. Be careful not to damage the shaft.
There is a woodruff key for the pulley and one for the impeller.

Remove the large circlip which sits in front of the bearing and drive out from the opposite end. Be sure to protect the end of the shaft from damage by using a sacrificial block of wood. The shaft is now free of the bearing and seal body.

Now, after removing a small circlip in front of the bearing, I used a bearing/pulley puller to pull the bearing off the shaft.

Puller with added socket on end of shaft

As the bearing came down the shaft, I used a small socket between the end of the shaft and the puller, to facilitate the last little bit to get the bearing off. You can see that in the picture to the right.

Now, replacing the seal surface is as simple as pulling out the old one with ones fingers and placing in the new one with a gentle push with the fingers. White side of seal (running surface) goes opposite the bearing and towards the sprung seal assembly.

In getting ready to reassemble, I cleaned off the matching surfaces of old gasket and proceeded to make a new one. For some reason my kit did not include this gasket. You can see the impression of the cut out to be, made in the gasket paper to the left of the pump body. Careful use of scissors and a hole punch made this easy work.
Now for assembly.....
First, I used a fine wet and dry sand paper to rub off all rust, nicks and burrs that were on the shaft.
With the one circlip on the other side of the bearing which was not removed off the shaft, I used this as the guide to which I would drive the new bearing on the shaft to. I used a small spark plug socket which was just the right size to slide over the shaft and seat against the inner race of the bearing. Using gentle taps with a hammer, I drove the bearing onto the shaft. It is important at the start of this, to make sure it is on square to the shaft as you make the first taps with the hammer. I finished with a piece of stainless tubing I had, to drive the bearing up to the circlip and then placed a new circlip on the other side of the bearing which keeps the location of the bearing on the shaft at the exact point needed. At all times, the force must only be applied to the inner race of the bearing. If you drive the bearing on using the outer race of the bearing, damage can be done to the bearing before it is even put to use.

Now place the shaft and bearing assembly through the bearing body and drive the assembly into the body by now driving on the outer ball bearing race. Small taps with a sacrificial block of wood and hammer will drive the assembly in till such time as you can now place the large retaining circlip which keeps the bearing/shaft assembly inside the bearing body.

Finally for the shaft, place on the spring loaded seal arrangement, compress the spring and place a new circlip to retain the assembly against the running surface. This can be seen assembled in the photo to the right.
With the gasket between the interfaces, present the bearing body to  the pump body and secure with the two threaded bolts. Mine were somewhat rusty, so I took the opportunity to put two new ones in with anti seize used on the threads.
Replace the two woodruff keys.
I didn't replace the cam inside the pump body: my kit had the wrong one and the old one was still OK. Also, I didn't replace the carbon bearing in the end of the cover plate. That was also OK, and while the carbon ones are easy to remove by breaking out from the recess, that can also be the demise of the new one when replacing; if one is not careful. These should be a finger push fit when done right, but heavy hands can also break these carbon bearings. Mine was OK, so I decided best to leave alone. After all, I'm not in a location where spares are easy to come by.
I leave the impeller out of the pump body until I'm ready to put it into service. I've seen too many pumps come off the shelf with impellers with distorted blades, just because they have been sitting in one spot inside the pump for many years.
The end cover was placed on the pump and the four retaining bolts finger tightened. Now it is wrapped in plastic and ready for the next time I have to replace the raw water pump due to leaking.
Hope that helps with your project.
Kit about $150 verses new at about $400. Time, about four hours.

Replaceing Raw Water Impeller on a Yanmar

While you do not need to replace your impeller with every oil change best to replace yours before a failure. This is a simple procedure anyone can accomplish. The following is a 2GM20F which is similar too most common Yanmar configurations.

Tools
Sockets for removal of pump and pump cover.
Razor or gasket scraper.
Small hammer.
Impeller removal tool (if available).

Supplies
New impeller and gasket.
Lithium Grease

1).IMPORTANT TURN off the engine freshwater thru-hull.
2). Locate pump on starboard front of engine and remove the 2 mounting bolts. Slip belt off pump.

  Once removed loosen the hose clamps and rotate the pump so you can access the pump cover.

3). Remove cover nuts. A light tap on the side of the cover should it stick will make it pop right off.

4). Now with cover removed note the orientation of the impeller blades as you will set the new impeller blades in the same direction.

(you may not see the missing blade yet)

 5) Using an impeller tool if available or simply pull out the old impeller. If it is stuck you may pry out or  grab using slip joint pliers. Just do not score the pump surfaces.

6). Notice the missing blade on the old impeller. It is important to located all the missing blades to ensure no blockage occurs.

Usually blades will be just outside the pump outlet (the right hand side here). In this case the missing blade was found in the hose  before the heat exchanger.

7). Now clean the impeller cover carefully with a razor and remove all old gasket material.

(as the pump wears the cover plate will outline the irregular shape of the impeller gasket).

Applying Grease

 

8). Now liberally grease the impeller pump inside surface and shaft. This allows the pump to run dry until water starts flowing and assist removal of the impeller next time.

9) Reinstall the impeller with all blades oriented the same as the old one. Apply gasket following the same wear lines on the cover. Add cover plate again lining up the wear marks.

10). Tighten the cover nuts in a rotating fashion so you do not warp the pump or plate. Place pump on engine and insert mounting bolts. Make sure to re-tighten any hose clamps you may have loosened.

11). Replace belt and tension with hammer handle and Tighten mounting bolts.

12). Now IMPORTANT Open the thru-hull. Start engine and watch for water. It might take a few seconds for the pump to prime and water appear in the exhaust.

13). Make sure to check for leaks

 

A Simple Home Made Bilge Pump

Finished Pump

Here it is. A simple home made bilge pump.

It is made of:

1" thinwall PVC about 24" long,

1" end cap,

1" street L,

24" fiberglass tent pole,

2 long screws that fit tightly in the hollow tent pole,

10-24 nut and bolt,

a piece of plastic cutting board cut to fit snugly inside the PVC tube,

some scrap inner tube rubber,

a wooden disk for a handle,

a little bit of Snoodle.

Output Port

Input Port

The Plunger Valve

I cut the plastic cutting board material to make a plug that was a snug fit inside the PVC tube. Then after drilling a center hole I drilled 4, 3/8ths inch holes around the center.

The Valve

Then I cut a piece of inner tube so it was just a little larger in diameter then the PVC tube, centered it on the tent pole, and screwed the holed plug on.

End Cap

I drilled a center hole in the end cap, and 4, 3/8ths holes around it. Then I used a rat tail file to elongate those holes, being careful to leave an area outside of the elongated holes on inside for the inner tube to seal against. Then using the center hole, I bolted another piece of inner tube cut to fit snugly to the inside of the cap.

 

I drilled a 3/8ths inch hole through the top center of the street L inserted the tent pole through the hole, and screwed a wooden knob to the outside end.

Then I just shoved the end cap on one end and the street end on the other. NO GLUE IS USED!!! 

The snoodle is just for a floatation test, I will adjust the amount of snoodle used to ensure the bilge pump floats.

It takes a few strokes to prime the pump, but once it starts pumping it works very well. I may sew a section of nylon cloth into a tube that fits snugly over the output port to aid in directing the water overboard. Credit goes to a Mr Anderson who published this on the internet. You will also find various versions of this with a Google search. Enjoy!

Recovering Distorted Raw Water Impeller

Reverse stress stake out

Some of us have left our boat for a season with the raw water pump impeller left in. Upon our return and check of the impeller, before puting the boat back in the water, we discover the impeller blades are permanently deformed and in some cases the deformed blades do not always touch the side of the pump body as it is rotated. I have also found the same to be true for new pumps I have purchased for spares. The pump has been sold with the impellor already inside, and who know how long it was sitting on the shelf. So, I remove the impeller and in the past have just thrown it out and either replaced for the pump to be used, or kept the new one outside the pump, and stored pump and new impeller in a zip lock bag, in my spares compartment.
Now, after I remove the impellor and  give the blades a good inspection for deterioration, I stake it out on a piece of wood with nails and distort the offending blades back in the opposite direction. I leave this for a few weeks/months until the blades look close to "normal" again.

You can see here to the left, an impeller that has about 3 weeks in it's reversed stress position and the blades are almost now at right angle to the body. This would probably be OK to reinstall, but will be given some more time.
If the impeller came from the raw water pump  about to be used. I just put in a new one to get the boat going, and place the "recovered one" into spares as it becomes "UN-distorted:"
This  trick should save me some money. I hope it does for you too!