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Discussion Starter · #1 ·
my tail housing has been wet for a long time. how much of a pain in the ass is the water pump gasket? i've tried sealing it with rtv to keep it from seeping but that just slowed it down. is there a way to tell if it needs the water pump before i tear into it? i want to get all my materials together in advance so i can get it in and out of the garage with minimal down time.
 

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The water pump o ring is very straight forward to replace. You'd have to pull the carbs then you have easy access. Are you sure the leak isn't from the weephole? If I was you and hadn't yet replaced the mech seal I'd order up one of those and do the shep's method. Once you have the pump housing off you have one nut to remove, pull the pump impeller and the seal is right there. I don't think you'd be fooling for more than a couple hours.
 

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Discussion Starter · #3 ·
i replaced the seal at the front of the motor that i thought was the mechanical seal. i'll look at the breakdown. i can't tell where the water is coming from but the paint on my transmission is always wet. i'll get a new o- ring and mech seal just to be on the safe side.
 

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+1, if you plugged the weep hole with RTV, that may force the coolant past the seal cup and oil seal and into the engine. Very rare for the big O-ring to leak, it's almost always the mechanical seal.



Since it's still leaking a bit, you probably haven't blocked it completely. If you do have goo in the weep hole, clean it out with a dental pick or whatever if you're going to be doing any riding before you get around to fixing it.
 

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Mechanical Seal? I have the back off the engine and cleaned up the entire inside, little bits of metal in the bottom of the oil chamber. Looked at the inside of the back houseing and noticed an area shiney from a (lined up with) bolt head rubbing againt it, bolt head of the timing head chain guide. Assumed the bits of metal came from this action bright stinny slight pocket.



Anyway - the seal that surrounds the cam shaft just under the pump ceramic washer has a micro spring coil under the lip of the rubber seal. The little spring was broken but not sticking out very far, easly pushed back into the rubber seal. I assume the little worm should be part of the compression holding the seal to the cam shaft thus should not be broken - Correct? Some wear on the cam shaft where the seal would normally ride, should I just put it all back together and hope for the best or should this "mechanical seal"(?) be replaced?



Inside the little rear cover is some caked on brown stuff which I'll clean before reassembly.



The whole reason for the engine pull and breakdown was a shorted to ground stator - all 3 yeallow wires, dead short to ground.



Thanks for any suggestions:

Bill Davis

Baldwin City, KS
 

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While you have the rear cover off, you should replace each and every seal. The oil seal is junk if the spring has come loose. If you get a complete gasket kit, it has all the O-rings and gaskets, you'll have to get the oil seals individually. The oil seals are nothing special, look them up for size on any of the Honda parts sellers, and then get them for less than half the price at any bearing house.



Seals, gaskets, O-rings and mechanical seals are expendable parts which shouldn't be re-used unless it's an emergency road side situation. Penny smart and dollar foolish.
 

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I'm going to piggy back on this thread, if that is ok with the OP. I have my carburetors pulled for rebuild at the moment, awaiting floats. I have some coolant deposits, very clean, on top of my transmission. My bike is very low miles, 10k. The deposits wiped up very easily, so this is a new leak. I probably should replace the seals while the tank, seat and carburetors are off. I am looking at the parts list in bandit's link. Since the coolant is clean, can I trust the 30 year old mechanical seal? I am about 65/35 split on changing/not changing the mechanical seal, considering the work involved using Shep's method.
 

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I'm going to piggy back on this thread, if that is ok with the OP. I have my carburetors pulled for rebuild at the moment, awaiting floats. I have some coolant deposits, very clean, on top of my transmission. My bike is very low miles, 10k. The deposits wiped up very easily, so this is a new leak. I probably should replace the seals while the tank, seat and carburetors are off. I am looking at the parts list in bandit's link. Since the coolant is clean, can I trust the 30 year old mechanical seal? I am about 65/35 split on changing/not changing the mechanical seal, considering the work involved using Shep's method.


I you've got the carbs out and the area clear behind the water pump housing, you're 90% there are far as "Shepping" the water pump mechanical seal. It took me about half an hour to do it on the GL500I once the carbs were out, but most of that half hour was because the seal had been leaking for decades in storage, and everything was a rusty mess. Bless the parts bikes, I chucked all the rusty hardware and put the shiny bits I had off a parts bike on it. The mechanical seal doesn't even have to be heated to separate, at least not the latest batch from Doward. Just a little back and forth and both sides came out with no problems.
 

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Maybe. The leak could get better with use as others have mentioned countless times before. If I was you and had the carbs off already I'd just replace it. Shep's method is quick and easy. Taking the carbs off is the hard part in my opinion.
 

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The mechanical seal doesn't even have to be heated to separate, at least not the latest batch from Doward. Just a little back and forth and both sides came out with no problems.


This sounds very promising. Is Doward a dude or a vendor?
 

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This sounds very promising. Is Doward a dude or a vendor?


Forum member who put together a group buy. Since then, the seals have showed up on FleaBay for around the same price ($20.00.)
 

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Forum member who put together a group buy. Since then, the seals have showed up on FleaBay for around the same price ($20.00.)


Cool, I sent Doward a pm and will check out ebay. I am looking for Yamaha part #11H-12438-10-00.



Local dealership, $28, not in stock, would deliver on Monday

Ebay seller, BIN, free standard shipping, $24.50

Dunno about Doward yet.
 

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The only issue I had when it came time for mechanical seal (of course I was doing cam chain and tensioner so the motor was out) was the impeller being frozen on the shaft. If you have that issue, spray it down with some PB Blaster and wait 5 minutes. It should come right off.



It is very easy. Follow Shep's method and keep track of all of the washers and which ones go where.



Fib
 
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