Print

Please login or register.

[KeelsonGraham]

The manual for my Universal M35 says to take off the entire water pump to replace the impeller. But looking at their diagram, I can’t see why you can’t just remove the impeller cover and replace the impeller without taking the whole sheboodle off the engine.

There must be a good reason for doing it the recommended way, but I can’t figure it out. What am I missing?

[Jim Fitch]

Keelson - I guess I never read the manual.  I just pop off the 3 bolts holding the cover on and replace the impeller and I've done it that way for decades.  Just remember, those are hard steel bolts and the cover is soft brass or bronze, so don't over tighten the bolts when you reassemble the pump.

Jim

[Ron Hill]

Keelson : As Jim mentioned, just remove those 3 bolts.  I always like to use some dishwashing detergent on the impeller so it slides in easier!!

A few thoughts

[KeelsonGraham]

Thanks guys. Just as I thought! I’ll do it the simple way.

[KWKloeber]

@KG

Non comprendo senor. 
The engine manual (pg 26 - REPLACEMENT OF SEA WATER PUMP IMPELLER:) says nothing bout removing the pump. In fact it cautions to not pull the impeller shaft out.

Could you post which manual and where it says to remove it?

Thx
-kk

[KeelsonGraham]

Here you go KW.

[KWKloeber]

@kg

Do you have an M35?  That’s not the M35 manual.

[KeelsonGraham]

Yep. I have the M35. The manual says M35B on it, so I guess it’s the right one. Every version I’ve downloaded shows the same procedure.

[Stu Jackson]

Here are some photos from an earlier thread:

https://c34.org/bbs/index.php/topic,4588.msg26957.html#msg26957

Photos start at reply #12, scroll on down.

[Ron Hill]

Keelson & Ken : It shouldn't make any difference if you have a M35 or a M35B engine.  If you remove the bolts (both) and the face plate (M35) you should be able to remove/change the impeller!!! The M35B Sherwood has the 3 bolts in from the rear abit the front (M35), but it's doable.  I've done it every fall so the impeller doesn't stay "scrunched up"  and reverse the impeller every spring!!


A thought

[waughoo]

My guess for the different proceedure is the location of the pump on the m-35B making it impossible to get to the bolts on the back side of the sherwood while the pump is in place.  The location of the pump on the m-35 is such that one can remove the bolts with the pump in place albeit awkwardly.

[Ron Hill]

Alex : You just need nimble fingers & patience when reassembling. I take mine apart every fall so I can inspect the impeller and then reverse/replace it in spring.

A thought

[KWKloeber]

Yep. I have the M35. The manual says M35B on it, so I guess it’s the right one. Every version I’ve downloaded shows the same procedure.

[** Edited]

@kg

The M35 Ops Manual does NOT state that the pump is to be removed to change the impeller.  The M35B manual DOES recommend removal.

I have posted at least two zillion times that the older non-B engines (e.g, M-35 and M-35A)  are completely different than the current "B" series engines.

Nevertheless, never ass/u/me that an engine w/ any model number (M-35 or M-25) uses the same manual as an engine with a different model number (M-35B or M-25XPB)!!!  Especially when, if one goes to the "manuals" page on the wiki website to download an Owner's or Parts manual -- there are manuals for the M35 and different ones for the M35B. 

As for the pump itself -- On the M35 there is virtually nothing in the way so it is relatively easy to get at the bolts.  On the M-35B (and M-25XPB) there is an engine belt in the vicinity so it is easier to remove the pump to service the impeller, than to try to finger out the bolts from the rear of the pump.  Not that it CANNOT be done in-situ, but many just find that it's simply easier to remove the two bolts and pull it.

The other reason that (I believe that) Westerbeke may say to remove the pump is due to the problems it had experienced with the shaft seizing up in the Sherwood iron-body pump and snapping off the pump drive on some of the "B" engines (see pic below.)  Removing the pump affords a very quick assessment of the pump and the shaft action and whether there is any corrosion that is affecting the iron body portion of the pump.   YBYC but if I ran a Sw pump I would invest the scant amount of time once a year that it takes to remove it to check it!!
But I prefer using the studs that I show below in place of the bolts.

**[When using a Sw pump the studs use 2 holes for the L clips and the 2 unused holes are closed off with 6mm set screws that are lock-tighted in place.]

[KeelsonGraham]

Is there any quick way to find out whether one has an M35 or M35B? The manufacturer’s plate on mine says “Universal M35 B C”!

P.S The impeller cover came off without too much trouble and without removing the entire pump.

[Stu Jackson]

Is there any quick way to find out whether one has an M35 or M35B? The manufacturer’s plate on mine says “Universal M35 B C”!

.....

KG,

Look at the photos I linked to in my earlier post.  IIRC, it says M35B.  Perhaps someone here can post a photo of their M35.  Or maybe you can post a photo of the front of your engine and compare it to my link's photos.

Then, of course, there's the drawing on the front of the manual you posted, and if that doesn't match what you have on your boat...