Engine Cooling Water Pump
Printed From: Laser 28 International Class Association
Category: Laser 28 General
Forum Name: Maintenance
Forum Description: All the things to care for your boat
URL: http://www.laser28.org/forum/forum_posts.asp?TID=499
Printed Date: 22 November 2024 at 5:36pm
Software Version: Web Wiz Forums 11.03 - http://www.webwizforums.com
Topic: Engine Cooling Water Pump
Posted By: Bill Brock
Subject: Engine Cooling Water Pump
Date Posted: 25 October 2011 at 9:31am
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The cooling water pump on my engine failed just as I was about to pull the boat for the season. It wasn’t the impeller, it was the shaft/bushing. If you look at Page 34 in the Laser 28 Owner’s Manual you will note that the water cooling pump is driven by a vertical shaft which has a gear (Item 40) in the oil sump of the engine. You should note on Page 43 that the cooling water pump which came with your engine has an internal stainless shaft inside what appears to be a bronze bushing. Over time these surfaces wear and will eventually allow water to go into the sump of the engine. When the pump fails in this manner it will continue to pump water through the cooling system so you will not know it failed unless you regularly check your oil or look at the pump when the engine is in operation. There is a hole in the side of pump housing and water will pour out through the hole, some of which will also go into the oil sump of the crank case. Since my boat was the first production boat I would strongly suggest everyone regularly check the pump or even replace it with the newer model pump which has a bearing in place of the bushing. Water in oil turns the oil a milky color and this can cause a catastrophic engine failure.
Johnson Pump (http://www.johnson-pump.com/jpmarine/marinedistributorsusa.html) is the distributor for the pump worldwide. The manufacturer that supplied the original bushing pump for the Bukh engine also makes the replacement pump with ball bearings. Apparently the older style bushing pump is also available. Here are the ball bearing pump part numbers: Qty Item Part Number (1) Water Cooling Pump (ball bearing) 10-35157-3 (2) Clamps 01-43238 Note also that the two Clamps identified above replace Item 51, Flange, on Page 34 since the bearing requires a housing larger in diameter than the earlier bushing design. This larger diameter also causes a clearance issue when you tighten the bolts which hold the pump to the housing beneath it. To secure these bolts you will need to purchase a twelve point 13 mm box end wrench and grind down the outside wall so it will fit on the head of the bolts. The Clamps go on with the flat side up against the bolt head. I found it easiest to remove the impeller to align the shafts during pump installation. I also took off the Elbow for Breather Pipe (Item 5, Page 34) for easier access during installation, but I kept the nuts on the ends of the four bolts to protect the threads. Note also that your impeller, the pump cover plate, and the screws which hold it on the bushing pump are the same as on the bearing pump, so save those parts as spares. Items 53 and 54 (Page 34) from the bushing pump will fit on the bearing pump. All three items (pump and two clamps) with shipping should cost about $300 US. Considering the age of these engines and the potential consequences I believe this would be money well spent even though your original pump may not be leaking quite yet. If you decide to replace the pump I would also suggest that you check your oil filter at the same time. To do this you will need to purchase a 17 mm open end wrench. I would also recommend that you bend the handle of the wrench about 15 degrees to provide easier access to the Locking Screw (Item 10 on Page 34). You may have to remove the Oil Pressure Switch (Item 11, Page 34) to remove the Locking Screw, but I was able to get mine off without removing it. I did have to grind down the face of my wrench to get it on inside the Oil Pressure Switch. E-mail me if you have any question at wmabrock@gmail.com. An ounce of prevention is worth a ... and most likely save you a lot of money. Bill |
Replies:
Posted By: Winner
Date Posted: 25 October 2011 at 10:01pm
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Very interesting Bill and thanks for the great description. Another weekend project for the list! Chris Eclipse #240 |
Posted By: meholden
Date Posted: 10 February 2012 at 11:57pm
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I just changed mine last weekend and thought I'd add my observations.
Thanks for the really great info, it helped a lot because I wasn't sure where the water was dripping from, but I noticed the weep hole and my oil was pretty foamy. The new pump and the wrench-grinding sounded like a hassle so I tried to find the original pump but I couldn't. So I ordered the parts above, and brought my grinder and some cheap wrenches to the marina. My original bolts were 12mm so try it out before you grind a 13mm wrench. My bolts were really rusty (PB Blaster got them loose) so I replaced them with allen head screws (M8 x 25 I believe). I was able to get them installed with a regular allen key (L-shaped), slipping a box end wrench over it for leverage. So I avoided grinding my wrench to fit. Now I can run the engine without mopping up after! -Mike (Firebolt) |
Posted By: Seawolf
Date Posted: 23 March 2012 at 11:31pm
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Sort on subject, but can someone please answer this question regarding the Cooling Water Switch. I have one wire leading to this and I discovered it is not hooked up. The wiring diagram shows one wire, however there are 2 post on the sensor, one is wider than the other. Should there be a second wire? If not, than which post does the wire connect to? Lastly is there a way to test to see if the sensor is working? Thanks
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Posted By: Bill Layton
Date Posted: 24 March 2012 at 12:07am
| It plugs onto the small terminal... you may have to use pliers to get it to stay on |
Posted By: Seawolf
Date Posted: 25 March 2012 at 2:32pm
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Thanks for the response. So what is the purpose of the other wider tab? The electrical diagram does shows a symbol for ground. Is it for that? should there be a wire connected to this to ground it? Or the fact the sensor is already attached to the engine is sufffient grounding? Sorry for all the "electrical for dummies" questions.
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Posted By: frfletch
Date Posted: 11 April 2012 at 5:15pm
| I think you will find that the other tab is to receive a wire for a temperature guage if you opt for one. |
Posted By: Seawolf
Date Posted: 11 April 2012 at 5:45pm
| Yes your right, my education has advance much since my last visit. I did opt for one. I will be getting this from keith at Crinmar. In addition I have since pulled the thermo housing and gave it the vinager bath. So I am making progress towards the spring launch! |
Posted By: frfletch
Date Posted: 11 April 2012 at 6:12pm
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Seawolf: If you are running in salt water, please do one more check an that is where the cooling water re-enters the exhaust elbow. The cooling water comes from the head via a 1/2" ID hose that connects to a barbed fitting on the exhaust elbow whose ID is 1/4". If there is any rust flaking coming from either your cast iron head, or the inside of the steel cylinder cooling ports, they will jam up that 1/4" hole, the engine will overheat, and before you know what has happened the head gasket will be compromised. This will allow some water or vapor to get into the cylinder and you will have a much bigger project on your hands. A bit of vinegar won't help you. If you find any sign of rust flakes accumulating where the hose meets the small barbed fitting, then I strongly suggest that you install one of those small raw water inlet filter in that hose between the head and the outlet. The instructions will say that these fittings belong only on the intake side, but ignore that and just install the little filter such that the arrow is pointing in the correct position. This will allow the screen filter to pick up the flakes and prevent blocking the outlet. Then check that filter occasionally and empty as required.
I had this problem and it led me to rebuilding my engine. In other posts on this site you will find my explanation of how I fitting a heat exchanger to my engine an no longer run raw water through my engine and sleep much better. At the very least, if you are running in salt, you should plumb a separate pick-up on the intake side so that when you put the boat away each time after use you can run a bucket of fresh water through it. This is very easy to do. |
Posted By: Bill Layton
Date Posted: 11 April 2012 at 6:45pm
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The best place to check if you have any rust sediment buildup occurring is in the bottom of the head cooling passages. Gravity allows the sediment to collect at the bottom of the smaller passages in the head. This is where it effects you first. Your are quite correct Frank about it causing blockages and eventually overheating and killing the head gasket, resulting in a rebuild. This problem only occurs in 2 instances, if you are in salt water or if you drain water from the engine for the winter layup without adding antifreeze. Both of these scenarios cause the inside of the cooling jackets to rust, allowing a rusty sediment to collect. The solution is to remove the lowest water jacket water supply tube. You'll find this on the bottom of the aft starboard side of the cylinder head..... the cooling hose attaches to it coming from the thermostat housing feed. There are 2 bolts holding that cover in place. Remove the hose then the 2 bolts and pull off the cover and there will be an open water-jacket port.... be sure all the rust is scraped out of here and re-install the assembly. I have done this to a few engines and found it to be plugged with rust sentiment and wondered why the engine hadn't overheated and killed the head gasket. Once it's all done remove each cooling hose and blow thru each one to see if it's blocked. If its blocked pull apart that section and clean out the affected sediment
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Posted By: Seawolf
Date Posted: 11 April 2012 at 11:04pm
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Thanks for the heads up, no pun intended. The boat did see a trip to the bahamas about 12 years ago. After the trip the owner had the engine overhauled. That being said, the boat has been and will be in fresh water, every winter it has been winterized with antifreeze and left in the engine. The manual does state you need to drain the antifreeze but I don't think many do this. Based on another thread, I have check all the hoses and blown them out, all were clean. I did order a new exhaust elbow (the old one had a series of cracks & instigated me learning more about this engine) also order various gaskets for the elbow and thermo housing. But I will follow up on the last suggestion and see what I find! I am still working on the stop solenoid and the water sensor element which I posted in "electrical 101" Suggestions? |
Posted By: frfletch
Date Posted: 11 April 2012 at 11:12pm
| I am sure that someone like Bill or Keith Strut may have another way of checking the temperature alarm, but why not try heating the sensor with a heat gun with the engine off, but ignition on. |
Posted By: bal149
Date Posted: 04 May 2012 at 12:09am
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re the thermostat housing. When I bought my boat I found the yellow wire to the alarm was cut. Why? I reconnected it but the alarm would sound and the light for temperature would light up-turns out the thermostat housing was rotated 180 degrees- for some reason, either the motor was overheating (unlikely) or the temperature probe was getting a false reading. As the alarm also warns that oil pressure is low or the membrane is leaking, I certainly felt that unplugging it was not smart. If your boat tells you it is running hot check this before getting worried
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Posted By: frfletch
Date Posted: 04 May 2012 at 1:52am
| That's an interesting one. Why would someone rotate the housing. I have a spare engine in my garage. Tomorrow I am going to look at it and see how this could be done. Weird! |
Posted By: bal149
Date Posted: 05 May 2012 at 1:14am
| the housing was rotated because the mechanic was stupid-no other conclusion can be drawn- the alarm was disabled because the owner was stupid-see above |
Posted By: frfletch
Date Posted: 05 May 2012 at 1:29am
| Yes. It is always interesting to see what previous owners have done with boats that we end up owning. The entire inside and outside of Voila had been painted by the previous owner. It looked like he painted the outside with a broom from an inflatable with Topcoat single part PU. That all had to come off which was not easy. Then he got busy with a roller on the inside with some kind of enamel as well, so anything I do down there requires stripping. And then he varnished all the crappy woodwork with some sort of orange tinted product. I am in the process of sourcing some foam core fiber glass paneling from China with which I intend to replace all the wood inside of my boat. I can't figure out why that paneling is so expensive in North America and so hard to get. It is all over the street in China and the make it for the North American market. Here it costs like gold. There 3/8" panel costs about US $8.00/m2. Here it is about $8.00/ft2. The only problem is that I don't need the usual minimum order of 300m2, so I'm looking for some that may have fallen off the back of a truck. |
Posted By: WJRyan
Date Posted: 05 May 2012 at 7:33am
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tell me more about the wood fletch, what are you rerplacing? And what is the wood you are referring to? Can you share a link to show us? Maybe "we" could help..... :)bill ------------- Bill Ryan, Room4Crew, #155 |
Posted By: Bill Layton
Date Posted: 05 May 2012 at 8:23am
| Charles remember the wire attaches to the smaller terminal of the water temp switch. The housing is symetrical so it makes no difference which way it is installed. Assuming of course that the plumbing (Y-pipe stb side)was installed correctly. |
Posted By: frfletch
Date Posted: 05 May 2012 at 10:49am
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Regarding wood to replace, I will start with the galley and totally rebuild it to the same configuration, but replacing all plywood with glass/foam composite. Next I would do the head area, Then the long strips of ply that house the engine and holding tank.
Next I will replace the main bulkhead, but I won't use the same paneling for this as it is structural and most likely it will be a glass/foam layup of my own development which will incorporate in it the athwartship stiffening currently done by the retrofitted aluminum bar. There is nothing wrong with my current bulkhead, except that someone varnished with this orange tinted junk. Also, I think it is epoxy glued and riveted to the hull and athwartship stringer, and I would prefer a glassed-in connection. For the time and trouble of stripping all the varnish and re-finishing in situ it won't take that much more time and effort to build a new one and eliminate the wood altogether. I have been instrumental in bringing 3 more Lasers into the Vancouver yachting area over the past few months, (there are lots of deals around), and several of those boats' joinery is in much worse shape than mine. Lots of rot, particularly in the head and on the head/nav bulkhead, so when I take mine apart to use the old ply material as a pattern to cut the new composite, I may as well cut three of everything and spread the bits around. Also, all the other boats that have come in, save one, need new floorboards, and if we have the composite, why use wood? If you have knowledge, or a connection to a reasonable supply of either 3/8" or 1/2" composite paneling, I would love to know of it. Mostly this material is commercially produced for the construction of trailers, RV's, and for the paneling on large delivery trucks and light weight containers. It seems the marine industry is either too small or too fragmented to attract the marketing efforts of the Chinese manufacturers. However I know of a yard in Hong Kong who brings panels in by the container, and then uses what they need and sells panels to DIY people and other small yards. All my friends in Hong Kong buy from them for their projects. I suppose I could buy from them and ship from Hong Kong, but the materials will have been double-shipped if I use that source, plus I will be paying his mark-up as well. I have considered laying up the panel myself, and I did do this back in 1978 in Hong Kong when I built the interior of my custom built 1/4 tonner, but the modern manufacturing process uses vacuum and achieves a quality finish on both sides, which I would have to go to great lengths to achieve. Thanks for any assistance you can lend. Frank |
Posted By: Guests
Date Posted: 10 May 2012 at 10:19am
| Hi Frank - could you start another thread based on your interior mods? I for one will follow with great interest as the interior of Andiamo is also in need of updating. |
Posted By: frfletch
Date Posted: 10 May 2012 at 11:13am
| I will be happy to, however while I have built the interiors to other boats, I have not yet gotten into my own Laser. I am trying to good quality light-weight composite paneling to work with and as soon as I do, I will start working on my own boat and post progress, procedure, methods, photos etc. I expect to be back in China and Hong Kong next month and will focus on sourcing materials. These materials are available in North America from such suppliers as Jamestown Marine, etc., but they area really expensive. This stuff is mass produced and is not actually expensive at all from the manufacturer. I just have not been able to find a retailer or wholesaler outside of the marine industry from which to buy it. As soon as it comes from a "Yacht Shop" the price goes up 10 times. |
Posted By: Winner
Date Posted: 18 May 2012 at 10:55pm
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Hi everyone. Back to the water pump (original topic in the thread) I have a parts/price list from Keith that he sent me in the Fall of 2011 and he's offering a water pump exchange where he sends you a rebuilt water pump and you send yours into him within 14 days. Cost is $228 which is cheaper than the method described above and also avoids the reduced space clearance issue.
------------- Chris Eclipse #240 Thunder Bay, ON |
Posted By: Seawolf
Date Posted: 29 May 2016 at 2:03pm
Curious, I have this wire in the larger post for the past four years. This year, my alarm went off, a high pitch, soft alarm. I always assumed my alarms never functioned before. I checked the engine temp with a hand held infrared thermometer, the engine was at 55 degrees celcius. I disconnectes the wire and alarm went off. If I put it in the smaller post and alarm stays off. I also checked oil and there is no water leaking thru the membrane. Just to be sure I checked the entire cooling system from water strainer to thermostat nothing to indicate water not flowing thru.Any thoughts? Faualty sensor? Or do I just have my wires crossed? |
Bill Layton wrote: