GT 40 Sherwood water pump
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Engine Repair
Forum Discription: Engine problems and solutions
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=51114
Printed Date: November-22-2024 at 9:39am
Topic: GT 40 Sherwood water pump
Posted By: tjca77
Subject: GT 40 Sherwood water pump
Date Posted: April-29-2023 at 7:31pm
| How can I tell if my water pump is broken? I had my impeller installed upside-down and am concerned it is broken. Reinstalled correctly and still no cooling water. Boat is on a lift in the lake. |
Replies:
Posted By: bwinn
Date Posted: April-29-2023 at 10:16pm
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TJ, How long was it run backwards? Did you peak at the impeller before you reinstalled it? It may have burned up from running dry. Some times the blades of the impeller can look ok but the rubber body will slip on the brass hub causing overheat. |
Posted By: tjca77
Date Posted: May-01-2023 at 7:02am
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It ran backwards for less than a minute. I pulled the impeller and confirmed the blades are intact. I didn't notice the body slipping on the key. I will pull again and check. I read a previous thread on here indicating it was easy to burn up the water pump, and that combined with the fact that the second install with the cam screw pointing towards the oil pan also failed to suck water has me concerned. I spoke with Nautique Parts yesterday and they suggested revving the engine to get the pump to suck water? Is this common practice? I have never had to do that before and do not want that to become common practice. Thanks again for the help and suggestions. |
Posted By: KENO
Date Posted: May-01-2023 at 7:43am
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I'd probably ....... Take one end of the suction hose off (like back at the suction strainer or the inlet to the transmission cooler), Fill it with water so the pump will prime easily, hook it back up, Make sure all the suction side fittings, strainer O ring and housing are tight and Start the engine with a quick blip to a couple thousand RPM and see if things start flowing Sometimes a prime is needed if the suction line was completely drained |
Posted By: tjca77
Date Posted: May-01-2023 at 9:05am
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Thank you, will prime everything on the suction side and reconnect. I also have a new impeller on the way, just in case. I need a spare anyhow. It is going to be a few days before I get back to the lake, just want to have any parts I might need before I go. But don't want to throw money away on uneeded parts. Like I mentioned before the cooked water pump comments have me worried. Thanks again. |
Posted By: tjca77
Date Posted: May-14-2023 at 9:55pm
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Good news, got the pump primed and it is pulling water. I filled the the hose off the bottom of the water pump till water came out of the intake on the hull. The not so good news is I still have a drip at the water pump housing. Is the next step a new water pump? The drip is what made me change the impeller to start with, I thought the paper seal must have failed, but that doesn’t seem to be the case. I did not run the boat at more than idle, didn’t want to get out on the lake and generate more than a drip or 2 out of the water pump. |
Posted By: KENO
Date Posted: May-15-2023 at 9:27am
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How's the big O ring on the impeller housing?. The spacer plate is sandwiched between that O ring on one side and the paper gasket on the other side on your vintage pump In the picture the screwdriver is in one of the holes https://ibb.co/qyLjs3D" rel="nofollow">  Look closely and maybe the water is dripping down from there. If that's the case, your mechanical seal is leaking. Some people drive for quite a while with a leaky seal if the leak isn't too bad. You can buy a seal kit to replace your leaky seal. Not the easiest job, especially if there's a lot of corrosion in the housing, but not too bad either If you're dead set on a new pump, you have choices. You can buy a new Sherwood G21 for 750 ish at SkiDim or shop around for better pricing You can buy a DJ pumps (South Korean company) for about 255 bucks on Ebay http://www.ebay.com/itm/264662868185?hash=item3d9f22e0d9:g:adYAAOSwChheaAD9" rel="nofollow - link to pump on Ebay Here's a little DJ pump discussion on CCF http://www.correctcraftfan.com/forum/forum_posts.asp?TID=48608&title=dj-aftermarket-rwp" rel="nofollow - link |
Posted By: Mpost
Date Posted: May-15-2023 at 10:13am
If you dont have this book, download it. Lot of good info and picture of the pump assembly.  https://www.go2marine.com/Product-Guides/MFR/Sherwood/Sherwood_Catalog_ENGLISH.pdf" rel="nofollow - https://www.go2marine.com/Product-Guides/MFR/Sherwood/Sherwood_Catalog_ENGLISH.pdf ------------- 84 SN Sold 98 SN Lund Pro V 1975 Alumacraft |
Posted By: MrMcD
Date Posted: May-15-2023 at 11:20am
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The leaking pump might also be the reason your pump would not prime. It is getting air rather than sucking up water as it should. You should double check all the hose connections between the pump and the water inlet at the bottom of the boat. Any loose hose would allow air to suck in and reduce the ability to suck water as it should. A leak between the pump and the engine would not cause any of this. Only the inlet side affects the ability to suck water in. Fixing the hose leaks obviously won’t fix the leaking pump but it is a good idea to double check the inlet side hose connections at the same time you fix your pump. ------------- |
Posted By: tjca77
Date Posted: May-15-2023 at 8:00pm
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Thanks all. KENO, yes it is leaking from one of the holes. Not a fast drip at idle but nonetheless still present. As I think back I believe I saw this a couple times last year but it was never consistent so I didn’t address it, shame on me. I have the Sherwood raw water major parts kit, https://nautiqueparts.com/sherwood-raw-water-pump-major-repair-kit/ from Nautique Parts on the way. Just shy of 400 with the Pnd discount. I read a little on pressing the bearings and not sure that is in my wheelhouse. I replaced all hoses a few years back, and checked the gaskets while trying to troubleshoot yesterday, all is well there. Hated to spend the $ on the major repair kit, but also noticed some squealing from time to time that I’m thinking could be related. Should have the part here this week and will install this weekend and report back. Thanks again for the responses and resources, it is much appreciated. |
Posted By: tjca77
Date Posted: May-15-2023 at 8:06pm
| Good info on checking all hoses on the pick up side of the pump, I will make sure that is done as well after re assembly. |
Posted By: KENO
Date Posted: May-15-2023 at 8:32pm
Should be an easy job for you since the kit you linked to is all assembled and you just use the old impeller housing and associated parts and you should be good to go.
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Posted By: KENO
Date Posted: May-15-2023 at 8:55pm
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I can't help but notice that those thoughtful people at nautiqueparts will sell you the DJ raw water pump mentioned earlier in this thread to save you some money compared to buying a new Sherwood pump. It's in the http://nautiqueparts.com/replacement-for-sherwood-raw-water-pump/" rel="nofollow - link Sherwood from NP............ 749 bucks NP's aftermarket DJ pump............ 499 bucks Same pump on Ebay............. 255 and you can also find it for 211 dollars on Ebay from various importers (with no name cast into the impeller housing) You must be paying double the price for the privilege of buying it from them |
Posted By: tjca77
Date Posted: May-22-2023 at 8:09pm
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Thanks all. Got the Sherwood major parts kit installed, and all is good. No more leaking and water is flowing great. All hoses are sealed and engine is running nice and cool. I guess after 23 years of service the original bearings on the pump wore out. Keeping it as a spare in the unlikely event it is needed, it may be a weekend saver. |