G20 Reduced Flow Under Load

Thanks, did you use the Sherwood Major Repair Kit 12665?

I’m going to use the money I will save by not going to a packers playoff game to have the guy from Illinois on eBay rebuild my pump this winter.

I’m glad that my water pump only weeps like a Bears fan. I’m going to wait until it weeps like a Packer’s fan before I rebuild it.

If I remember right you're an engineer at a power plant.

You must have something called "post maintenance testing" or some variation of those words after something is repaired.

Just say that you're now a little smarter based on your experience

Well, since you're curious, a long time ago( that translates to 35 or so years) I had a problem with the original wire reinforced hose from the transmission cooler to the RWP leaking.

The wire was poking out through the outer layer of hose and the inner layer was cracked and that made for cooling issues if you know what I mean..

Not having the internet to educate me and not liking that wire reinforced hose, I used some 1 inch heater hose. Double layer with fabric reinforcement in between.

I never had any issues with collapsing the hose due to RWP suction vacuum. and have used the same stuff on multiple boats over the years.

The "canned response" is you gotta use wire reinforced to avoid hose collapse but the only way the hose might collapse is if it's bent around to tight a radius and kinked or if your suction path from the lake/river is blocked by let's say weeds or plastic or you have a through hull shutoff that you managed to leave shut.

By the time you might have an issue with the hose,collapsing you've probably fried the impeller anyways from lack of water going through it from any of the above causes.

As long as the hose can withstand about 10 inches of vacuum and you have water flow through it, it ain't gonna collapse.

The double layer heater hose is easier to tighten down and get a good seal especially on things like the brass hose ends of the transmission cooler as compared to the wire reinforced stuff.and It can easily withstand the vacuum one of these pumps draws.

If I had a really tight radius, I'd go for the wire reinforced but it's pretty easy to avoid the tight bend radius with a little thought put into the hose routing and length used..

I do keep a piece of wire reinforced hose around though to remind myself how much I dislike the stuff

I pulled it out just before I wrote this.

So, yes wire reinforced works just fine but it's not for me.

I'd tell you what I use but it would just start a long discussion full of disagreement about suction hoses so we'll let you get some answers from others.

I don't have to worry about poking myself with a piece of wire though

I have that drawing printed on an 11x17” sheet on my desk at work right now. The original spacer plate is the round one with no holes. I replaced it with the symmetrical triangular one. Paid a few bucks extra to get the special hose from skidim that says Pleasurecraft Marine Engine Company. The hose that failed was a precut automotive wire reinforced that looked out of place anyways. Maybe someday this site will support mobile photo uploads and I will have a field day.

Wisco

One thing to keep in mind is that you're talking G20, Gary is talking the later G21.

There are other small differences in the pumps like you'll probably find a spacer between the pulley and the outer bearing while the later ones have no spacer but a snap ring instead

The spacer plate between the body and the housing is different and the body itself is different where the spacer plate sits.

None of this really makes any difference as long as you're careful taking it apart and noting what goes where.

And do it the way Gary said and you'll be fine. Even with the pulley off, you still disassemble the same way .

Ahh. I am going to try and remove the pulley if it comes off easy.

So when you press the shaft out with the pulley on, are you just breaking off the snap rings on the pulley side?

The Sherwood instructions/graphics look so much easier and prettier than your real life photos/practical insight.

I’m aware there is potentially damage to the shaft or pulley already.

If I get the pulley off and on easily, is it easier to do the rest of the work according to the Sherwood instructions?

To press the seal back in I used a 1 1/4" piece of plastic pipe...... sorry about that

None of the 6 that I have done Cole had a pin,they were all interference fit with a snap ring. Don't follow the Sherwood book literally They have you install the seal then the snap ring that is under it next,just put it together in the order you took it apart.

I have seen the more detailed discussion on the other site

https://www.planetnautique.com/vb5/forum/nautique-topics/maintenance-technical-discussion/11121-rebuilding-sherwood-raw-water-pump/page2

My assumption was that the use of the key, set screw, pin, and snap ring meant that it wasn't an interference fit between pulley and shaft.

I have the Sherwood procedure and also the info from plantnautique. I will stand by..

Take your pump apart as far as you can and hold loosely in a vice. Pry as much of the seal as you can out. It will look like this-


Then you can reach in and remove the thin steel retaining housing with a punch,might have to do some prying,just have to be careful not to get overzealous. It will look like this with it out-


Now you will be able to reach in and remove the snap ring and using a press like in the first picture remove the shaft with the pulley still on.

Remove the big snap rings that hold the bearings in and the press them out,I start them off like this just to get them moving



Then switch over to my plate to get them completely out of the housing,be careful not to loose the spacer that is between the two bearings





I have a blast cabinet so I clean up the housing and paint,you can just wire wheel or wire brush it



With it cleaned up they go back together way easier than coming apart,assembly is the reverse of taking them apart When replacing the seal I use a short piece of 1" plastic pipe so that it presses on the outside housing of the seal but yet clears the pulley shaft.



This cheap Harbor Freight press has already paid for it's self when I replaced the front axle u joints on my Jeep. Now everything it does is free

Thanks a lot Ken. I have several good impellers and didn't need a new cam so I did not buy the kit. I also needed hardware for the pulley assembly (G20) that didn't come in the kit.

I bought new bearings, seal and seat, several new gaskets and O rings, and all the retaining clips and pins. We will see how this strategy pans out. I will update later. Thanks again.

Cole