Rebuilding Sherwood E35 raw pumps

[MakinTime]

Hi guys, I am considering doing a major overhaul on my Sherwood raw water pumps. I am not sure if they have ever been done. I was planning on replacing impellers anyways so I thought it would be a good piece of mind to get everything done.Has anyone done this? Sounds like the bearing needs to be pressed into the housing and the shaft any tricks I need to know? Also looks like you can buy the kits with or without the cam which one to buy?

One other thing.. the pumps seem to work great pump plenty, do not leak, and last year when I replaced impellers bearing felt smooth. Should I even mess with it? Thanks!

[Viper]

I wouldn't mess with it. Yes change the impellers but if it's not leaking or squealing at this time, spend your money and time on something that needs more immediate attention. Having said that, there are benefits to being proactive but this is usually something that will give clues before it fails. The key here is to inspect critical hardware periodically.

[MakinTime]

Good to hear, thanks!

[km1125]

I always wondered how many hours before you'd need to replace the cams. Seems like they would HAVE to wear down some over hundreds of hours, but how much? I've never seen a measured spec from a brand new cam to compare against an old one. You'd think that would be an easy measurement to take when you're doing impeller replacements. The cam is what determines displacement and ultimately the pumping capacity of each revolution.

[jcoll]

I just did a major on my port pump this year. The clue it needed done was water leakage on initial start-up 1st run of the season. The issue never reoccurred all season. When I disassembled the pump I found the shaft was heavily pitted near where the seal rode. New shaft was required too. The water in the Chesapeake Bay is tough on equipment! The only original parts when the job was done were the housing, pulley, and bracket. I'm speculating here but, since I've owned the boat there has always been a puff of steam from the port exhaust while cruising. This year so far I've not seen the same. It's not producing any steam at all. I'm thinking the cam may have played a role in producing more water flow which is keeping the exhaust temp. a bit lower. Not sure - time will tell.

You will need a press to do the job. You should take some measure so you can orient the pulley back to its proper position so belt alignment is correct. Having said all that, I wouldn't do it until it gives me a reason to. Impeller change - yes but a major is a judgment call.

[km1125]

I've also thought about switching over to crank-attached pumps. They are much less expensive to replace the whole pump rather than just rebuild the Sherwoods that are on there.

[bud37]

Jcoil.....I have an idea you resolved your pump issues by replacing the pitted shaft and seal....that would probably have allowed air to be sucked in while running and in the process ruining the efficiency of the pump, for the most part all that cam does is compress the vanes allowing them to create a small vacuum when they spring out straight.

I also would like to see more about the crank pumps as I was checking out my installation the other day and merc only has one bracket holding the pump in place , thus allowing some mis alignment of the pump pulley which I believe would put undue pressure on the pump bearing.... ( not good )....what say you folk???? Where is a good place get these?........

[mjk1040]

New pumps I've seen run from $252.00>$703.00. What's a complete rebuild kit run?

[MakinTime]

Thanks for the replays guys..I found the rebuild kits with cams for around $100 a piece not to bad. But I think I will change impeller and see what everything looks like before doing a rebuild. I really like the Crank mounted idea.

[Viper]

Crank mounts are great. Pretty easy install and way easier to service the impeller.