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Experts help me fix this weep hole leak

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Still trying to fix my 11 450 that pissing coolant out the weep hole. I firstly changed the mechanical seal - no change. There was a fair amount of up and down movement so I bought another seal, oil seal, bearing and gaskets took the engine cover off and this time took it down to a bike mechanic I occasionallly use and had him change the bearings and seal this time. The only thing not replaced was the shaft he gave it a linish to clean it up. I WAS READY TO ORDER ONE WHILE ORDERING THE REST OF THE STUFF BUT EVERYONE SAID SHOULDNT NEED TO AS IT'S A LOW HOUR BIKE. Well put it back together and guess what it pissed out 30 secs after start up worse than before. Other than the bloody shaft everything was replaced and the mechanical seals are 35 bucks a shot. Should have I in hindsight changed the waterpump shaft?

Could it be something else anything ???

Some advic plz....:busted: this is doing my head in about to push it off a cliff

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did you by any chance put the seal in backwards?? a friend of mine put his in backwards and couldnt figure out why it was still leaking after he put it all back together..

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did you by any chance put the seal in backwards?? a friend of mine put his in backwards and couldnt figure out why it was still leaking after he put it all back together..

One would think so as its a common mistake but its in correctly with the spring side facing outwards

thanks anyway

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could it be a dodgey radiator cap over pressurizing the system and forcing the coolant out the weep hole? it also doesnt take much damage/wear on the impeller shaft to cause a leak

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when you get the cover off again, post some photos.. and there in no way should have been play in the seal. it should have to be tapped/pressed in.

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We always replace the shaft with the seal and bearing , the shafts get a wear spot on them and new seals just don't want to seal ,we even tried to'save' a shaft by 'cleaning ' it up , never worked. Since doing the pump complete , no problems ever .:lol:

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when you get the cover off again, post some photos.. and there in no way should have been play in the seal. it should have to be tapped/pressed in.

I will take pics today. The seal was pressed / tapped in the play I felt in the start was bearing related I thought.

I regret not changing the shaft now it means another seal again too :lol:

May replace the copper washer as well this time

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We always replace the shaft with the seal and bearing , the shafts get a wear spot on them and new seals just don't want to seal ,we even tried to'save' a shaft by 'cleaning ' it up , never worked. Since doing the pump complete , no problems ever .:lol:

yep should have replaced the lot have you done an 09 & up model ?

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yep should have replaced the lot have you done an 09 & up model ?

They didnt change the design of that part of the motor, so change it all.

Wanna hear some crap?

I had that exact same problem one day. I was at a VetX race at Glen Helen and it started pissing pretty good when the bike was cold then it seemed like it would stop when it was hot. So I just raced it, and topped it off before the second moto and raced it again. Then I forgot about it and went to the track...it leaked a little, I remembered, got pissed and just topped it off again and kept an eye on it that day....and then it just quit leaking. Its been 4 years now :lol:

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They didnt change the design of that part of the motor, so change it all.

Wanna hear some crap?

I had that exact same problem one day. I was at a VetX race at Glen Helen and it started pissing pretty good when the bike was cold then it seemed like it would stop when it was hot. So I just raced it, and topped it off before the second moto and raced it again. Then I forgot about it and went to the track...it leaked a little, I remembered, got pissed and just topped it off again and kept an eye on it that day....and then it just quit leaking. Its been 4 years now :lol:

Shaun I know you know these things backwards what would you recommend next?

Put a new shaft and another seal in making the whole assembly new?

One suggestion was apossible head gasket but I dont know about that. There was no water in the engine oil and besides the coolant pissed out after 30 seconds or so without the radiator cap being on to pressurize the system anyway :)

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If you can blow all the coolant out in 30 seconds, you probably Do have a blown head gasket. Typically they wont loose all the coolant that fast with the damn drain plug out of the water pump cover so something is pressurizing the system and that would have to be the cylinder.

You dont have to get water in the oil. It MAY get water in the oil when the HG is gone, but its not a given.

Id fire it up with no coolant, plug the over flow line on the rad and see if you get pretty significant pressure there pretty quickly (10-15 seconds) Just hold your palm across the rad cap hole...you'll know if its wrong PDQ.

Ive seen the WP seal leak because the seal wasnt driven home in the case too though. The run out in the shaft on some of them is enough to let the seal run off the edge of the shaft if its not driven all the way in. Ive got a CR500 thats like that.

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If you can blow all the coolant out in 30 seconds, you probably Do have a blown head gasket. Typically they wont loose all the coolant that fast with the damn drain plug out of the water pump cover so something is pressurizing the system and that would have to be the cylinder.

You dont have to get water in the oil. It MAY get water in the oil when the HG is gone, but its not a given.

Id fire it up with no coolant, plug the over flow line on the rad and see if you get pretty significant pressure there pretty quickly (10-15 seconds) Just hold your palm across the rad cap hole...you'll know if its wrong PDQ.

Ive seen the WP seal leak because the seal wasnt driven home in the case too though. The run out in the shaft on some of them is enough to let the seal run off the edge of the shaft if its not driven all the way in. Ive got a CR500 thats like that.

Sorry Shaun incase I have not explained myself clearly it doesnt pump all the coolant out in 30 secs. The first start up after putting it together after seals ect it started dribbling out the weap hole 30 secconds after I started it. Now it runs out the weep hole as soon as I fire it up and its worse now than when I pulled it apart earlier. The shaft was linished not replaced and seeing it's worse now than before Im starting to think the shaft is fubared?

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This was a more common problem on the first Honda 450s ('02) and in my opinion got a bit better every year. Two things are the cause of this issue if you have ruled out seals and bearings as you have. It all has to do with the fact that the water pump is driven by the counter balance shaft. By design, a shaft that is purposely out of balance. Bearings don't like out of balance shafts especially if they are not held securely on the outer race. If the counter balance shaft wobbles it will cause the water pump shaft to wobble and leak.

First, the right hand side bearing (deep groove ball) of the counter balance shaft seats into the engine case on the OD. It is not a press fit - the bearing slips in. Because of this, if the tolerances are not perfect, the bearing will spin on the OD and wear away a little of the case because of the unbalanced shaft. This makes it looser and allows it to spin easier. Once that happens there is a bit of radial play and the shaft can wobble. Even with new seals, bearings, and shaft, it will cause the water pump shaft to wobble and leak. I have used two fixes. If it is not bad, loctite bearing lock may work. The other option is to use a pointed punch and upset the case in several evenly spaced locations around where the bearing seats so it is a tight fit. Also, there is a little clip that clamps he bearing axially. I have bent this a bit more so it puts a bit more clamp load to help lock the bearing in place.

If this fix does not work, it is possible that the bearing on the left side is worn causing the wobble. It is a roller bearing that seats directly on the shaft so either or both could be the cause. Based on the low hours I doubt this is the issue.

Good luck.

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Durkot is probably right on this one. That seal doesnt have much of a flexible side wall in it so if the bearing is bad and allows the shaft to wobble on its axis and the seal wont be able to chase the shaft very far and its going to leak. If youve already replaced the bearings and the fit was good in the cases...the shaft may be the source even if it looks good.

When you put the new seal in, did you lube it at all? If not, it could have been damaged on the first start-up or during install too.

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chance is big that the seal is not driven in correctly or deep enough, this way you do not get enough spring pressure on the seal.... I have seen this problem before with newbies to this new mechanical seal set up . Check both parts of the seal that they are infact in there correct place .

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This was a more common problem on the first Honda 450s ('02) and in my opinion got a bit better every year. Two things are the cause of this issue if you have ruled out seals and bearings as you have. It all has to do with the fact that the water pump is driven by the counter balance shaft. By design, a shaft that is purposely out of balance. Bearings don't like out of balance shafts especially if they are not held securely on the outer race. If the counter balance shaft wobbles it will cause the water pump shaft to wobble and leak.

First, the right hand side bearing (deep groove ball) of the counter balance shaft seats into the engine case on the OD. It is not a press fit - the bearing slips in. Because of this, if the tolerances are not perfect, the bearing will spin on the OD and wear away a little of the case because of the unbalanced shaft. This makes it looser and allows it to spin easier. Once that happens there is a bit of radial play and the shaft can wobble. Even with new seals, bearings, and shaft, it will cause the water pump shaft to wobble and leak. I have used two fixes. If it is not bad, loctite bearing lock may work. The other option is to use a pointed punch and upset the case in several evenly spaced locations around where the bearing seats so it is a tight fit. Also, there is a little clip that clamps he bearing axially. I have bent this a bit more so it puts a bit more clamp load to help lock the bearing in place.

If this fix does not work, it is possible that the bearing on the left side is worn causing the wobble. It is a roller bearing that seats directly on the shaft so either or both could be the cause. Based on the low hours I doubt this is the issue.

Good luck.

Oh crap this sounds like Im getting in over my head.:lol:

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Durkot is probably right on this one. That seal doesnt have much of a flexible side wall in it so if the bearing is bad and allows the shaft to wobble on its axis and the seal wont be able to chase the shaft very far and its going to leak. If youve already replaced the bearings and the fit was good in the cases...the shaft may be the source even if it looks good.

When you put the new seal in, did you lube it at all? If not, it could have been damaged on the first start-up or during install too.

Umm no Shaun I didn't lube the seal when it was put in. I went down to the dealer today and ordered a new shaft, another seal and spoke to them and agreed this time I would get them to change the shaft and seal and check the everything over and then I will take it home and re install the case and hope like hell it works otherwise it's going over a cliff :lol:

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i have replaced 4 or so wp seals on my 2 bikes.. (many many hours) and the seals come with some grease already on em from the factory. Not much, but it doesn't need much. Not a bad idea to add some, but there is some grease in there already.

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when you get the cover off again, post some photos.. and there in no way should have been play in the seal. it should have to be tapped/pressed in.

Here are some pics

mx160.jpg

mx159.jpg

mx158.jpg

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