NOS pump impeller still good or deteriorated with age?

[Scow Hound]

Asking quick opinions before I buy a water pump impeller for my new to me 1971 weedless Lightwin. I found a (New Old Stock) NOS impeller kit for sale out there in internet-land. Brings up the question: Any concern about the plastic/rubber on a NOS impeller breaking down over time? Lets say it's sitting on a shelf or in a drawer in its original packaging for 6-10 years(or longer). The incentive to buy this kit is if the older bottom plate would match OEM thickness of .036", whereas I read a review that the new Sierra plates are about .015" less than original. Kinda leery of replacing a really old impeller with an un-used old impeller. Do you think that old un-used impeller might be brittle or somehow broke down chemically? Also I see some Chinese knock-offs for $5-$6 that scare me, or all they all made there anyway?--thanks for any thoughts-Scow

 

[oldboat1]

sounds like you are getting the whole kit (not just the impeller). I would buy the oem kit, and use it for a season. Monitor temps as you would normally do anyway. Check the impeller at the end of the season,

 

[alldodge]

Asking quick opinions before I buy a water pump impeller for my new to me 1971 weedless Lightwin. I found a (New Old Stock) NOS impeller kit for sale out there in internet-land. Brings up the question: Any concern about the plastic/rubber on a NOS impeller breaking down over time? Lets say it's sitting on a shelf or in a drawer in its original packaging for 6-10 years(or longer). The incentive to buy this kit is if the older bottom plate would match OEM thickness of .036", whereas I read a review that the new Sierra plates are about .015" less than original. Kinda leery of replacing a really old impeller with an un-used old impeller. Do you think that old un-used impeller might be brittle or somehow broke down chemically? Also I see some Chinese knock-offs for $5-$6 that scare me, or all they all made there anyway?--thanks for any thoughts-Scow

Howdy

IMO rubber will break down over time, I would use a 5 year old, but not much older. For what an OEM impeller cost isn't much when it comes to protecting the motor

 

[HighTrim]

Is your current plate actually damaged? They are pretty durable, and rarely need replacing. I personally would not put in a 10 year old NOS impeller. They do dry rot from sitting.

 

[oldboat1]

If you have a line on an inexpensive NOS kit including the oem housing, plate and impeller, it could be a good find -- whether or not you want to use the impeller. The housing is a pretty expensive item ($100 or so).

 

[Scow Hound]

No Title

The plate has a circular gouge a couple thousandths deep where the outside of the "drive grommet" rides. I guess if I make sure there is no raised edge it would be alright? The remainder of plate is more like polished than worn. Also I can't rule out that the water tube grommet is original, but it is pliable so no woes? If that all makes sense, then I could just go with a replacement impeller. I had to remove the drive shaft to get the deformed impeller drive off, so it looks like I have to pull apart the gearcase to put the pinion back on?? in which case, I'll purchase and and install new oil seals, as they are likely original. Any insights?

 

[HighTrim]

From at I can see that plate is fine, if there are no grooves in it just use it. The polished look is normal. You very well MAY have to open the gearcase now, and as you stated, for the cost of a seal kit, you may as well do that while you are in there.

 

[Scow Hound]

No Title

After coming up dry searching the forums for "seal puller" "seal tool" etc, I had to employ my West Virginia Engineering skills and make my own seal pulling tool. I thought I'd share in case it helps someone else. I scrounged a piece of 1/8"@ 309 stainless heliarc rod from the insurmountable pile of "useless stuff" my wife wants me to divest myself of. Bent/hammered hooks on ends, bent in half around a 3/8" rod, scrounged a slotted chunk of steel "just sitting around in the way" and used it as a slide hammer against a rod at the top. Inserted into seal and with a few rapid/firm whacks that seal flew right oughtta there! Pic to follow.

 

[Scow Hound]

Hi guys, not sure if I should start a new thread or if this qualifies as continuing Saga on my lower unit refreshment project: Researching water pump, I see there is a new style pump assy with plastic housing and cup insert. So the question now is whether the upgrade pump assy gives a performance/durability improvement over the original? And whether the upcharge is worth the upgrade? My initial impression is that the original impeller has a longer "throw" on the blades, although half as tall as the smaller diameter new style impeller. I'm planning on long periods of low speed operation (trolling off a canoe) and it seems the low rpm "displacement" operation of the impeller might be better with the longer bladed original design? Or maybe the new design is just superior in all aspects? Thanks for response, I hope my left-handed input here on the forum is interesting to some.--Hank

 

[HighTrim]

You got it out, that's the main thing! This is a seal puller, for the drive shaft style seals.

http://www.princessauto.com/en/detail/seal-puller/A-p2990539e

The original style pumps have been running strong for many decades. I personally don't usually change them, unless the guy Im working on the motor for wants one. They are apparently superior, according to those smarter than myself. I personally don't think it matters either way, they should be last the 3 to 5 years or so, until you change it again. So don't worry too much about it.

 

[Scow Hound]

Status update: I drained the oil, of which there was only about 5-6 tablespoons. Oil is clean, a nice amber/brown color. There seemed to be some oil migration at the upper driveshaft seal, so maybe some escaped there during usage. That seal is out, and I don't believe I contaminated the gearcase during removal. I had no luck removing the lower "bearing housing assy". It has never been removed and original paint is intact, which I scored with razor knife, but it's stuck enough that I feel I would crack something if I got more aggressive. Next try might be to heat it with a paint stripper gun, but I'd rather not. I did get the screws out with an impact screw driver. So I figured I might abandon the idea of opening the propeller end, as the seal appears fine, with original paint too--IF I could get the driveshaft engaged again, which, maybe a stroke of luck, but I turned her upside down and worked the shafts until the pinion gear meshed. So now I checked for run out and slop at the propshaft, and there is almost no side to side slop, and maybe .032 front to back linear movement. Surprisingly smooth actually. SO...Does anyone think that 45 year old prop shaft seal will last much longer? Actually, as I type this, I think if someone gives me some magic trick to get it apart, I'd probably change it...well, it's late TTYL-

 

[lindy46]

Pressure test the gearcase - put 5-10psi in there and see if she holds. If it holds, I wouldn't change the seal. If it aint broke . . . .

 

[Scow Hound]

Well I'm back to inform everyone that indeed I found the magic method of disassembling the gearcase unit. First you have to procrastinate while waiting for parts and forget that you left the retainer screws out of the gearcase. Then taking advice, pressurize the lower unit seals to 6 PSI and when that holds increase it to 16 PSI and right around 11 to 12 psi, POW! Out flies the entire gear case! CAUTION: STAY OUT OF THE LINE OF FIRE!! Recommend some form of restraint, bungee cords, etc, to avoid injury to both self and equipment! Here's a pic of the mondo pressure tester I made from parts off the insurmountable pile, with purchase of a Schrader fitting and o-ring for less than $5. Per instructions here on the forum, I drilled out a 3/8-16 x 2" bolt, however I used a 3 point carbon steel bolt and a lot of Kroil spray. Well Serendipity smiled on me when she blew apart with no damage, and now all seals and o-rings are new and holding 18 psi. Oh, the other trick that worked on the gear case seal, I used my heat strip gun to preheat outside the seal and it popped right out with a screwdriver. Now I Should be good for another 40 years on the seals eh