Weepy Water Pump

[coy55boy]

I put the bike up on the lift to do an oil change and noticed staining around and below the weep hole on the water pump. I've read a few threads that mention replacing the impeller with a metal one. Can someone point me to a supplier that carries the necessary parts?

[friesman]

I got mine from partshark.com......Mine weeps a bit whenever there is a big temperature change, even after the metal impeller was installed. I think its a real common issue, and as long as mine doesnt ever increase to more than the tablespoon or 2, I aint doin anything with it as it only leaks when the temp drops below freezing.

 

Brian

[skydoc_17]

Hey Stephen,

Inside the water pump, there is a ceramic seal, (much the same as a seal in a swimming pool pump) The seal retracts from the mating surface when Temps. drop. A small amount of coolant weeps from the hole in the pump housing when this happens. Unless this happens when the temps. are up to riding temp., or you see a LOT of coolant on the ground on a warm to hot day, then this is a bit pesky, but not a major concern. The impeller you are speaking of, actually moves water thru the water pump and the engine. The early MKI VR's used a plastic impeller, which would decompose over time and reduce the amount of water that would circulate thru the engine. The symptom of that plastic impeller would be overheating. So if you are going to remove the water pump to address this problem you will need to replace the seal as well or the leak will still be there when you are finished. (A new impeller alone, will not solve the leaking problem)

There is one more thing I want to mention here, I consider myself a pretty fair mechanic, and I have only been able to manage a 60 to 70 percent success rate at rebuilding these water pumps! The MKI water pumps are the worst! Because of play in the impeller shaft, and the quality (or lack of) of the impeller shaft itself, even replacing the seal does not guaranty you a leak free water pump. 28 years of heat, and water on an aluminum water pump housing, and a low quality quasi-stainless steel impeller shaft don't leave you much to work with on that rebuild. Most VMAX owners replace the water pump with a new one because they have too much money invested in their engines to risk overheating do to a leaky water pump. I don't attempt to rebuild water pumps here at my shop any more. I guess what I am trying to say here is, wait till spring when the weather warms up, and if you start seeing a BUNCH of coolant coming from the water pump at that point, then you may want to examine you options then. I am not saying that this condition is "Normal", but it is to be expected from a 28 year old motorcycle and most of the First Gen. owners see this very same thing at one point or another in the colder states, or when the temps. dive in the warmer ones. I would say you are OK for now, just keep an eye on the coolant overflow bottle and top off as needed.

Earl

[GeorgeS]

As I recall, only the 84 and 84's had the plastic impeller problem. It was a recall item.

If dealer did job, there should be some type of stamp on the engine case someplace. But not sure where.

The weeping is a fairly common problem, but usually clears up. Run the engine and see what happens.

 

If you do a rebuild, its easy to do. Pull up the IPC, you need the new seal, bearing, and a bunch of Seals, and a new gasket for the cover. If you order all the parts, including the impeller, from Yamaha, its around $100 to $120 for a complete set of parts.

Its a good Winter job !! Took me about 3 hours to do the rebuild,

[saddlebum]

Hey Stephen,

Inside the water pump, there is a ceramic seal, (much the same as a seal in a swimming pool pump) The seal retracts from the mating surface when Temps. drop. A small amount of coolant weeps from the hole in the pump housing when this happens. Unless this happens when the temps. are up to riding temp., or you see a LOT of coolant on the ground on a warm to hot day, then this is a bit pesky, but not a major concern. The impeller you are speaking of, actually moves water thru the water pump and the engine. The early MKI VR's used a plastic impeller, which would decompose over time and reduce the amount of water that would circulate thru the engine. The symptom of that plastic impeller would be overheating. So if you are going to remove the water pump to address this problem you will need to replace the seal as well or the leak will still be there when you are finished. (A new impeller alone, will not solve the leaking problem)

There is one more thing I want to mention here, I consider myself a pretty fair mechanic, and I have only been able to manage a 60 to 70 percent success rate at rebuilding these water pumps! The MKI water pumps are the worst! Because of play in the impeller shaft, and the quality (or lack of) of the impeller shaft itself, even replacing the seal does not guaranty you a leak free water pump. 28 years of heat, and water on an aluminum water pump housing, and a low quality quasi-stainless steel impeller shaft don't leave you much to work with on that rebuild. Most VMAX owners replace the water pump with a new one because they have too much money invested in their engines to risk overheating do to a leaky water pump. I don't attempt to rebuild water pumps here at my shop any more. I guess what I am trying to say here is, wait till spring when the weather warms up, and if you start seeing a BUNCH of coolant coming from the water pump at that point, then you may want to examine you options then. I am not saying that this condition is "Normal", but it is to be expected from a 28 year old motorcycle and most of the First Gen. owners see this very same thing at one point or another in the colder states, or when the temps. dive in the warmer ones. I would say you are OK for now, just keep an eye on the coolant overflow bottle and top off as needed.

Earl

Also with a water pump housing depending on what type of coolant has been used there could be a fair amount of cavitation and errosion on the housing impellar face, so putting in a new impellar does not necessarily gaurantee proper flow. If you do install a new impellar check the clearance between the impellar and the housing impellar face to make sure that there is not to much.

[coy55boy]

Thanks for all the tips! Maybe I'm being overly cautious. I like to fix things BEFORE they leave me stranded! I saw the stains on the pump cover and panicked. I haven't seen any evidence of leakage on the garage floor. The coolant level is correct. The bike hasn't been running hot. And we haven't really had a temp change...it was 80 and sunny yesterday. I guess I'm just looking for an excuse to stop riding so much and do some wrenching instead.

[GaryZ]

On my trip to Kerrville last month the VR leaked a little coolant when the temperature dropped to 22 degrees F. It dripped from the thermostat and the plastic hose going into the water pump. Maybe a teaspoon from each. Never leaked any other time during the trip.

 

I assumed this was the typical problem discussed here and I have ignored it. Am I correct?

[skydoc_17]

Hey Gary,

The issue you mentioned is somewhat different. What you have is a metal thermostat housing and a plastic housing top, that sits extremely close to the right exhaust header pipe. Over the years, the plastic housing top gets warped and begins to leak because of the tremendous heat generated by the exhaust pipe. Also, your plastic water pump "Tube" is not leaking, the coolant is leaking from the thermostat housing and running down to the tube. This problem will NOT go away, and is only going to get worse as time goes on. The reason being is that you have a plastic part that is not physically flat any more because of the heat, and is not sealing the thermostat housing area any more. To get a shot at the thermostat housing you will need to remove the right exhaust header pipe, (unless you have the hands of a 10 year old girl!) and the radiator side grills as well as the radiator grill. When ordering parts, be sure to get the housing gasket, the large O'Ring, AND a new thermostat housing top. Yamaha makes an excellent thermostat, (and expensive) so if yours is functioning properly, it is OK to reuse it. While you have everything removed, take the time to replace the O'Ring on the radiator drain as well, you won't regret it. This will help you with that project:

http://www.venturerider.org/classifieds/showproduct.php?product=1724&title=first-gen1983-1993-radiator-drain-upgrade&cat=22

I have attached some pics of this project.

You don't want that plastic thermostat housing top opening up while you are a long way from home! (don't ask me how I know) If you have questions about the install, please feel free to PM me,

Earl

[mlew]

Is the upper thermostat housing available in metal? I have my 83 VR apart right now and noticed it was warpped and I would like to replace it.

[slipstreamer]

:stickpoke:This happened to me on both my 93 and my 84. Both times it was during cool temps. Once I rode both bikes after the fact, the seal re-sealed itself and never leaked again. As someone said earlier it is just the nature of the beast. Don't worry, be happy. Cliff

[slipstreamer]

Thanks for your post Earl. My 84 has been leaking coolant recently and I suspected it was coming from the thermostat housing. Now, thanks to you, I know why and what I need to do to fix the problem. Very helpful. Thanks again. Cliff

[skydoc_17]

Hey Cliff,

Thank you very much for the kind words! When I do a repair or upgrade to one of my VR's, I usually take pics of the process, and because I have a "soft spot" in my heart for anyone that tries to keep one of these wonderful machines running. Because I work on a lot of VR's here at my shop, I see more problems than the average VR owner would see in the normal maintenance of their bikes. I try to pass on any information I have about a problem I have encountered and been able to either repair, or come up with an upgrade so that a pesky problem can be dealt with once and for all.

I too have been able to keep my own bikes running as a result of the information other VR.ORG members have shared with me so this is my attempt to repay the members that have helped me. If my posts keep just one VR on the road, then the effort was worth it.

Thanks again for compliment,

Earl

[Venturous Randy]

Hey Cliff,

Thank you very much for the kind words! When I do a repair or upgrade to one of my VR's, I usually take pics of the process, and because I have a "soft spot" in my heart for anyone that tries to keep one of these wonderful machines running. Because I work on a lot of VR's here at my shop, I see more problems than the average VR owner would see in the normal maintenance of their bikes. I try to pass on any information I have about a problem I have encountered and been able to either repair, or come up with an upgrade so that a pesky problem can be dealt with once and for all.

I too have been able to keep my own bikes running as a result of the information other VR.ORG members have shared with me so this is my attempt to repay the members that have helped me. If my posts keep just one VR on the road, then the effort was worth it.

Thanks again for compliment,

Earl

 

 

That's a great response Earl!

RandyA