Might be another pump job soon

[pidjones]

About one drop of green fluid evey-other day under the '79. I've only riden it once, for about 45 miles, this season. I have done compression check (all in the 160's) but that's about all. I'll wait until it gets a bit worse. Probably will do seal replacement as replacing mechanical seals was a common task for machinest mates in the Navy. And I don't have to worry about keeping water out of the people tank on the bike.

Will update this thread as things progress.

 

[mcgovern61]

When the bikes sit, the water pump seal tends to drip. Once hot and running on a regular basis, it often swells back up again. I know on my 1100 it started dripping from sitting last year. I started running around the block to keep her operational and the dripping has completely stopped.

 

[kerryb]

Thats good to know. I put a waterpump in the aspy two years ago because there were a couple drips on the storage shed floor. The pump seemed okay but I replaced for an upcoming ling ride (2000 miles) last year when I opened the shed there was a drip, but not again for the season. If there is a drip this year, I'll chalk it up to sitting in the cold, and just keep an eye on it.

 

[pidjones]

I would have no worry if it was stored in a non-temperature controlled area, but it is stored in the basement garage which stays a pretty constant temperature year-round. I know of no part in a mechanical seal that can dry out. Now, they must leak just a tiny amount to lubricate the faces, but usually less than what evaporation takes care of.

I think it will make it through the season, though.

 

[Winger 82]

mcgovern61 » Thu Apr 23, 2020 12:23 pm[/url]":10x3bf16]
When the bikes sit, the water pump seal tends to drip. Once hot and running on a regular basis, it often swells back up again. I know on my 1100 it started dripping from sitting last year. I started running around the block to keep her operational and the dripping has completely stopped.

:good: :good: :good:

 

[DaveKamp]

pidjones » April 23rd, 2020, 10:29 am[/url]":5rkv05hp]
And I don't have to worry about keeping water out of the people tank on the bike.

:smilie_happy: :smilie_happy: :smilie_happy: There's probably quite a few that don't 'get' this reference, but as a well-worn 'river rat', son of a Navy man, and having had a business partner who was a machinist mate that wore a dolphin, I know EXACTLY what it means to keep water 'out of the people-tank'... :hi:

Okay, so the mechanical seal on these things is probably identical in concept to the seal on the front of the camshaft of my CX500s an dCX650's... I'll describe it, and if that's not accurate, someone tell me otherwise:

There's a sheet-metal cup pressed into the block, with a hole in the bottom for a shaft to pass through... and in that cup, is a recess wherin a spring sits. The spring includes a ceramic ring on a flexible skirt, that goes all the way to the cup. On the other end (in the case of the CX, on the shaft, under the mechanical fan) is a matching ceramic ring that has an elastomeric seal (neoprene perhaps) in contact with the shaft.

There is no friction between neoprene and any surface... the actual 'moving contact' surface is ceramic.

In storage, two things happen with this type of seal.

--First is that the chemistry inside the cooling system... impurities...tend to saponify or crystalize a bit, and some occurs at the junction of those surfaces, lifting slightly, and causing the ceramic seal to open a wee bit, allowing a drip... but not much.

--Second, is that seasonal temperature and pressure changes within a few PSI of atmospheric pressure SHOULD vent by displacement into the coolant recovery tank, but there's a slight minimum pressure check afforded in the radiator cap's design... less than a PSI or so. The slight variation of differential between ambient, and internal, is sufficient (particularly when negative) to cause the seal to skew a smidgen and allow a little weep.

In both of theses cases, there's absolutely nothing 'wrong' with the seal. In non-storage scenario, the movement of seal surface obliterates any saponification product, rejecting it from the seal, and restores alignment the contact surface. Commensurate rising temperature and pressure helps improve seal seating, thus sealing.

So like most every other aspect of the bike, having it sitting unused for long periods is just not good for it... exercise it several times a week, through the entire year, and you'd likely never see it happen.

If you ride, and it drips often, then it's time for a seal... but I wouldn't tear into it at this point. Rotate the tires and fuel a bit before making that call. :yes:

 

[pidjones]

One of my captain's favorite sayings. Mine was the "law of conservation of dirt" dirt can be niether created nor destroyed - just moved from one place to another. This explained why one random area failed field day inspection weekly. So far, only one drip evident each time parked (takes a day or too). At least one face isn't carbon polished to 3 helium light bands like the big main shaft seals (and split at that!) on the boat. Seals normally fail because of abrasive particles in the fluid they seal. Our big ones were constantly flushed with filtered sea water. Luckily we made no Med runs. Mediterranean water was known to contain a lot of "black diamond" volcanic sand. Those poor guys had to replace seals every run.

This is also why modern engines require non-silica antifreeze.