Quote from: kwaltersmi on May 05, 2017, 05:33:03 PM
I launched today with my M25 XPB and the Sherwood pump is leaking. After opening it up to check the impeller, it looks like the rubber on the seal (Parts 10 through 12 - 30288X) was torn and was coming out. It dripped about 1 drop every 2 seconds at idle on launch, but quit dripping altogether once I was underway for the 3 mile motor to my marina. No dripping when I arrived at my dock.
So...
Should I replace the seal in the Sherwood pump? Is this difficult to do? Should I swap in the Oberdorfer (is it 908?) pump instead? Should I leave it alone and wait for it to leak again even though part of the rubber from the seal came out of the pump when I opened prior to motoring to my marina?
There's only one "correct" answer.... YBYC, but.......... see below if you even consider keeping a pump that is designed to seize up...
Ok, got it. I should replace with the Oberdorfer. But is the N202M-16 a direct replacement for the Sherwood on my M25XPB? Or do I need the N202M-908? Or something else?
Quote from: kwaltersmi on May 05, 2017, 06:06:32 PM
Ok, got it. I should replace with the Oberdorfer. But is the N202M-16 a direct replacement for the Sherwood on my M25XPB? Or do I need the N202M-908? Or something else?
The 908 replaces the Sherwood. Unfortunately at a way overpriced cost. Or the -16 if you want a bolt on and aren't afraid to do the mod to the pump base. If you go thru the other thread I discuss trying to do a direct replacement bolt on. We did one, but now that Ob sold out to the big boys, they won't sell an undrilled base pump only in lots of 10 or 15 and at a premium price.
Ken
I ordered the Oberdorfer N202M-908 from Depco and will be doing the install this weekend (if it arrives in time). Thanks for the input.
Darn could've saved you a few bucks over Depco. Anyway, I would recommend instead of replacing the bolts holding the Sherwood clips, getting two double ended uneven thread studs (M6 x 1.0 around 30mm long) and nylock flange nuts, and lock-tighting studs into the pump land on the gear case. With the rather crappy metal of case, I don't like torquing bolts into it. Just a little safety measure if you need to remove and service the pump. With my pumps I supply a n/c stainless steel stud/nut Kit, but you can't buy those on the street, you'd have to use steel.
You need to file down the "inside" side of the square hub of the large (7/8 inch) hose barb elbow so that when installing the pump you can turn the other elbow past the large one. The OB pump ports are slightly closer together than the SW ports so there's an interference when you install the elbows. I file down to the point where the square hub is level with the hose barb extension. Unfortunately there's no elbows made directly to fit this that you can double clamp, but every time I put my hand on a hose clamp I replace it with an ABA or AWBA brand solid (not perforated) band. It would be a good investment - I've replaced every clamp on my boat ;-)
I'll try to find my picture of the hose barb elbow mod and post it for you when I get on my laptop.
Thanks! I think I saw the hose barb mod photos in the Wiki. Do you know the size of the hose barb fitting? I might see if I can buy a new one and do the mod at home before I travel out to the boat this weekend for the install since I won't have access to a grinder while at the boat to mod the existing barb fitting.
Here's the mod you need to make (pic 1). File down the hub on the larger elbow so it's even with the barb leg.
SLIGHTLY round off the end of smaller barb so it just turns by the larger hub.
I believe the wiki photos are for the M-25/XP elbows (slightly different than ones on the B series engines.)
I've seen the 1/2 npt x 7/8 elbow ONLY from Westerbeke, about 20 boat bucks. I did the one shown via Dremel - easy peazy.
Unfortunately they are brass not bronze.
While off, look inside the pump land with a bright light to make sure you have a reinforcing ring on the outside the camshaft fork (pic 2).
There's ways to install elbows that can be double clamped, not so elegant but the installs i did have worked very well (so far) pic 3. Notice it's my bolt-on flange mod, not clip-on 908 pump (will post a completed job pic later.)
kk
QuoteI would recommend instead of replacing the bolts holding the Sherwood clips, getting two double ended uneven thread studs (M6 x 1.0 around 30mm long) and nylock flange nuts, and lock-tighting studs into the pump land on the gear case.
Ken,
I ordered the 202-16 for my M25XPB a while ago and I planned on installing it this weekend. I noticed the nugget of info above and I'm wondering where to get double ended thread studs M6 x 1.0 around 30mm long? I've seen some online but they're shorter than what you suggest. Also, I'm not sure what you mean by "lock-tightening studs". I'm still on the hard so, I'll probably fit and temporarily mount with the old bolts and replace with what you recomend before the splash.
Bill
-16 pump? That doesn't fit the xpb without the major base mod and redrilling.
Finding them is the rub. I first got a set at a well stocked hardware store for the testing. Then had to special order all in stainless. McMaster-Carr might have them in onzie twozies.
I'll measure the min length you need and repost. The critical length is on the long side uneven thread. If you are using the -26 pump they can be shorter-- as they don't need to accommodate the Sherwood clips, only the thickness of the pump base.
Need to use lock tight on the threads so the studs don't back out when turning the nuts.
kk
Quote-16 pump? That doesn't fit the xpb without the major base mod and redrilling.
DOH, that's extremely disappointing. I bought it from CD and the salesperson said the mod was pretty straight forward. Apparently not. So, I not only need to grind a considerable amount off the base, I also need to drill a new hole for a stud/bolt. I guess there was confusion regarding the engine I have. I now see at the end of the "Replacing a Sherwood Water Pump with an Oberdorfer" article how extensive the mod is. Well, I guess I'll have to get the Kubota gasket p/n 16264-88130 and the studs, nuts etc... Wasn't figuring on all that.
QuoteNeed to use lock tight on the threads so the studs don't back out when turning the nuts.
Everything is right-hand thread so it should tighten when installing the pump, correct? Heck, if the right size studs are difficult to find I suppose I'll wind up going with bolts anyway. Is there a significant advantage the studs over bolts?
Bill,
Yeah major minor mod. along with a new hole, one needs to be enlarged (ovaled sideways.)
What's key is that there's no adjustment with the bolt-on, and the hose run is tight by the alternator, so positioning the "new" holes gets dicey. The one is close, but not right on and when oy enlarge it, it ends up very close to the edge of the pump flange.
I have some "beta" templates on CAD for the pump positioning -- my purpose was to make these from pumps with undrilled bases. I can't attest to the absolute accuracy of the template because Ob hadn't cooperated so well in supplying the pumps -- but it might help you?.
I used to use that Kubota gasket on the 908 pump installs but either it or the Wb gasket for the Sherwood will work. The Ob is a better gasket than the trashy Wb paper. But it might not seal as well, if that doesn't sound contradictory. With the Kb gasket, both the pump and the Sw clips sit against the gasket. With the Wb gasket (circle) only the pump is against the gasket. I can mail you one for a template if you need it?
A thought -- why not see if CD will take back the m-16 to CD (since they led you astray in the first place) in favor of a m-908? ($$$).
The original Kb old" gear covers came with studs!
ken
This was the beta test of the XPB bolt on with the double clamp-able fittings, it works fine and keeps onapumping, but would be better if rotated like 1- 2° CCW.
If you zoom in you can see the stud, flange nut and enlarged hole in the base. To rotate it CCW that hole would need to be more oval
Need to use lock tight on the threads so the studs don't back out when turning the nuts [to remove the pump for service.]
kk
I was thinking about trying to returning it for the 908. I guess with that one, since the base is round, you can rotate to obtain better clearance from the belt? Trying to get things wrapped up to launch by memorial day and this isn't helping. I'm thinking I might put the Sherwood back on while I sort this out. Nothin' ever simple, eh?
It's not the belt, it's the alternator itself and the 7/8" Hx hose.
Ridiculous that Westerbeke used a 7/8" inch hose for that, should have been a 5/8" barb on the Hx inlet.
We could've gotten the alignment spot on the first time, but we were doing this beta with a boat in VA, me between NC and NY, and the pump machining in GA. I didn't have an XPB that I could run down to and check so depended on photographs being spot on and vertical to get the angles all set for my CAD drawings. I believe the pump needs to be exactly 45° CW from vertical. Give or take a fudge factor.
ken
I put the 908 on my XPB this past weekend. Fairly simple install with just a bit of grinding needed on one of the hose barbs for clearance with the other elbow fitting. It probably took me 2 hours from start to finish with clean-up and a run test.
With the new oberdorfer installed, is it necessary to prime it on first starting the engine? If so does one prime it by just filling up the inlet hose with the bleeder loosened on the pump?
I installed a "216" on my 25XP with no bleeding/priming necessary.
I have an oberdorfer pump and have only had to prime it once. That occurred because i had the inlet valve open and changed the impeller when on the hard. Obviously the water all ran out. Since then i always close the water intake valve before changing the impeller and have not had another problem.
The one time that I did need to prime it, i just removed the effluent side and poured water into the pump. I reconnected the hose and it started up fine.
Quote from: Roland Gendreau on May 16, 2017, 06:16:13 PM
With the new oberdorfer installed, is it necessary to prime it on first starting the engine? If so does one prime it by just filling up the inlet hose with the bleeder loosened on the pump?
No priming was necessary for me.
Thanks. No priming was needed for mine.
Quote from: Roland Gendreau on May 17, 2017, 07:11:31 PM
Thanks. No priming was needed for mine.
Rubber impeller pumps such as the Oberdorfer are self priming to an extent, provided:
there is no air lock in the system.
there is a good seal on the impeller to the cover, and fins to the case. If the impeller or pump cover wears so there is a poor seal, it doesn't matter how good the fins are.
I use 120v and 12v impeller pumps to pull water up 10 feet or more.
I did the change too - Sherwood to Oberdorfer. However, my engine temp gauge now doesn't get much above 135 degrees - it was 160 before the change.
Is there any way to restrict the flow?
Since the temp difference occurred immediately after the switch, I don't think it is the thermostat.
Quote from: womble on May 25, 2017, 06:20:52 AM
I did the change too - Sherwood to Oberdorfer. However, my engine temp gauge now doesn't get much above 135 degrees - it was 160 before the change.
Is there any way to restrict the flow?
Since the temp difference occurred immediately after the switch, I don't think it is the thermostat.
Put your engine/year in your signature. You have an xpb per the subject?
The thermostat restricts the flow.
There can be several reasons why a temp gauge reads "incorrectly". First they are highly "plus or minus", like up to 15 degrees. Poor ground on the sender (a nortorious issue), bad connections at the panel.
Look at the teleflex gauge troubleshooting guide on the wiki and run thru the easy steps and let us know the results.
kk
Ken,
What, if anything, do you suggest using on the gasket between the pump and engine block?
When I did mine I just cleaned the engine mating surface and used the paper gasket--without any type of goooop. Works fine. No leaks.
Quote from: Bill Shreeves on May 26, 2017, 12:17:31 PM
Ken,
What, if anything, do you suggest using on the gasket between the pump and engine block?
Nada.
Which engine and whose gasket? Wb or Kb?
Ken
M25xpb, OB 908 pump with paper Universal part #302678 pump gasket. Need the diameter and thickness of the gasket? ;)
Isn't it pretty much just sealing out debris? I don't think water should be present at that seal.
Quote from: Bill Shreeves on May 26, 2017, 02:45:49 PM
M25xpb, OB 908 pump with paper Universal part #302678 pump gasket. Need the diameter and thickness of the gasket? ;)
Isn't it pretty much just sealing out debris? I don't think water should be present at that seal.
Sealing oil from leaking past the pump land.
Nothing needed, just the round Wb gasket. I prefer using Kb gaskets but that's irrelevant - still no goop needed / desirable.
kk.
Just a heads up that on my M35 I just replaced my Sherwood with an Oberdorfer from Ken and used the stud kit he provides. Has been working great. Was a slight bit of filing to mod it in to fit and on the original elbows.
Thanks for all the tips Ken. I'd recommend it and Ken's guidance, as and if needed.
Hawk
I installed the 908 on my M25XPB a couple of weeks ago along with new hoses and the fit was great. It only required minor material removal for the fittings to spin just as everyone said. There didn't appear to be any or much lubrication on the impeller so, I put a thin coating of vaseline on the impeller and interior wall of the pump that the impeller rubs against for some lubrication before the water made its way to the pump on start-up. Launched late last week and the pump works like a champ. No priming needed and the engine temps are what they should be.
Everyone....
Though it's not going to be fatal -- vaseline isn't the best thing to use on rubber.
EVERYONE should own a tube of SuperLube teflon gel lube. it's a STAPLE to carry on a boat.
Or use mineral oil (baby oil) or liquid soap.
Ken
QuoteThough it's not going to be fatal -- vaseline isn't the best thing to use on rubber.
Huh, still new to this after having completed only my first season. After reading more in to it after reading your comment, I now see this isn't good for rubber. I recalled reading to very lightly lube new impeller with Vaseline when I replaced the impeller on the Sherwood last year. Heck, I even stored a little along with my spare impeller for unplanned replacements. I don't recall the source and didn't think to question it. Should I open it up and clean it off? If so, what would be best to remove the vaseline with?
Thanks for the correction....
Bill,
As I said it's probably not fatal. But if you want to, i would use a paper towel and physically remove it, followed by Dawn dish soap scrub down to remove the film.
All : Maybe it works for some, but I would stay away from oil (petroleum) based products on "rubber" impellers or gaskets. Silicon is what I would recommend.
When installing an impeller it's best to use dishwashing soap to slide it in place.
my thought
Thanks for the info guys. Another item on the weekend list. Fortunately, it can't be much easier with my brand spanking new Oberdorfer pump!
Quote from: Bill Shreeves on June 15, 2017, 04:01:08 PM
Thanks for the info guys. Another item on the weekend list. Fortunately, it can't be much easier with my brand spanking new Oberdorfer pump!
Bill, just FYI also. Besides the Ob impeller, I keep a small bottle of baby oil aboard. A couple teaspoons down the sink drain and pumped thru makes a great lube for the head pump seals and cylinder/rubber on the piston. Since it's mineral oil and not petroleum based it makes a good lube for rubber/plastic parts that you can't get to very easily.
kk
that's a great suggestion!
The problem of putting any kind of lubricating "oil" in the head is that it will create an oil slick on the top of the holding tank contents, suffocating the aerobic bacteria, causing tank odors. This was something Peggie Hall always suggested not to do.
Quote from: Roc on June 19, 2017, 02:02:06 PM
The problem of putting any kind of lubricating "oil" in the head is that it will create an oil slick on the top of the holding tank contents, suffocating the aerobic bacteria, causing tank odors. This was something Peggie Hall always suggested not to do.
ROC
Will a tablespoon full say, 1x season or 1x month (depending on usage, need changes) be an issue? I'd think it would become emulsified with the pumping?
nevertheless, I have my tank so it completely empties @ pump out, of course that means along with any oil on the surface (if that's really an issue -- we're not talking a pint of it here remember)
ken
Hi Ken,
I would think a small amount is negligible. But I think Peggie's suggestion is to caution someone that puts larger amounts, frequently, that would cause a slick to form on the top of the tank. I think the key is using small amounts, for just this reason. What I do is lube the inside of the pump tube, and the rubber o-ring with superlube (non petroleum lubricant). I believe she suggests using that to lube the head also.
ROC,
I lube a new pump like that**
But taking apart one and re-lubing isn't saved in my "favorites."
cheers
Ken
** I believe under maritime law (and USCG regs,) SuperLube ptfe gel is a required carry-aboard on all vessels. And SuperLube ptfe dry lube as well (on sail driven vessels).
The gel is a lube, and is the same as SuperLube's dielectric "grease" product.
If it's not required by law -- just like gravity-- "it's a good idea."
Useful exchange. I note that Jabsco actually recommends regular lubrication of the inside of the toilet pump and the plunger and its big o-ring with Vaseline. I tried using lanolin for awhile. It lasted longer but did not like cold temperatures or water, both of which made pumping more difficult.