Modern Vespa

While installing my Leo Vince exhaust today I noticed this drip and surrounding filth from it leaking for what I think is a while.

Thoughts?

Look at the hoses above...

It looks like an overflow for the water pump? The hoses above are ok.

Bend,

Pull the floorboard and have a looksie. I am quite sure you will find your bad clamp there.

Best,
SDG

failing SDG's advice I was under the belief that's a sign of a leaking pump bearing seal?

That's a photo of the little nipple thing under the water pump, right?

That is the weep hole that the water has leeking from. My GTS has been doing that since I brought it home 3 years ago. It's a very small amount, and seems to happen when the bike sits for maybe a week or more, so not too often for me. I have only had to add coolant a few times as well, and a very minimal amount.

OR DO WHAT THEY SAY, GO TO YOUR LOCAL SUPPLY STORE AND PURCHASE SOME VESPA GTS COOLANT. 8)

Ya I took a quick look and was thinking it was pooling under the little exit hole under the floorboard as I have seen many times. Many more times than from the actual pump however now that I have had dinner and am nice and relaxed, um, ya, the floorboards aren't so much over the oil filter, hehe.

Anyway, weep hole, don't really ever see much dripping there however as another stated he has had mild dripping for 3 years with no real issue. Are you losing much coolant bend? With all the GTS's we have sold I have only seen a couple of waterpumps do the "salad bowl" thing and 5-10 clamps under floorboards, this issue you have seems very rare to me.

Good luck,
SDG

Water pump seal....

Looks like its leaking very slowly...have you had to add coolant?

Just keep an eye on it, and the coolant level.

PITA to change that. Special tools required for installing the new seal....ceramic methinks...

Weepy is not a big deal....little puddles would be bad.

R

8)

Oh, I forgot to add... RESULTS MAY VARY!

I think when I noticed this, I asked around a little and pretty much was told by a few people watch it, and see how it acts. Not much happened, so I never took it in for repair. If you have any worry about little critters slirping it up off the garage floor, then you might want to take care of it. Mine will probably get replaced sometime in the next year when I go to change the coolant. That will get done on a nice warm day with nice ice cold beer at my side.

A very sensible attitude. I've got a few similar non-urgent things to be sorted when the weather turns more clement here.

I just took a look at the parts break down on the water pump... Does not seem to be like all the ones I have done on cars and trucks. Which part would need to be replaced to solve the drip?

#4?
#12?
or another??

Thanks in advance.

#12 is the housing seal; seems like that would be the one. #4 is a seal between the crankcase and the pump shaft.

Thinking #4 is correct.

Oil on one side....coolant on the other. Any coolant leaking past the seal drains down to the weep hole.

The oil behind the water pump impeller/stator housing is not under pressure, but the cooling system is, so leaking tends to be toward the oil side/stator. The weep hole allows fluids a way to escape before pressure pushes it into the oil side of the motor.

Only seen pump one seal replaced...it looked fragile.

I will consult the oracle(guru) tomorrow and get back to you on this thread...

Hope this helps.

R

8)

I'm thinking that if water leaked past #4, it would wind up in the crankcase.

I think its a 2 part seal, one side for the oil, the other for the pump with a channel in the middle allowing fluid to escape to the vent hole.

Lemme speak to Rolfie tomorrow.

R

8)

If it's being opened I would replace both. Seals are cheap, beer is not.

SDG

Here is a closer up picture of it. The coolant is most definitely dripping from the weep hole. It is not running down the case from anywhere else. It has been a slow drip and no puddles have been seen on the floor. I await the Guru response...

Thanks guys and gals, just another reason why this site rocks.

Well, if it's not coming down the case, it couldn't very well be the #12 seal. Standing by...

I've been under the impression that the weep hole is there to...WEEP. Unless you are experiencing enough of a coolant release from there, that it is steaming up at every stoplight as it "drips" onto your hot exhaust...I think it's normal and thats some long-term build up from that.

Mine was actually pissing out that weep hole, and I needed a new pump cover with integral ceramic seal.

I would clean and then keep an eye on that area...

I have cleaned it up and will watch it over the next 500 miles to see if it gets worse.

Thanks everyone!

every GTs250 i've looked at has evidence of a weep from that outlet, mine certainly has, not a massive surge, just the odd hint of a drip 8)

+1.

Water pump.. i had mine replaced along time ago.....

Me too and it still weeps occasionally from the weep hole.

in my opinion this is a "system vent" and will have the odd drip......

Upon consultation with the oracle I have returned with the definitive answer....

It is indeed #4.

It is a 2 part ceramic seal which seals both the water pump and stator.

There is a vent in the middle of the seal to allow any leakage from the pressurized cooling system to vent thru the weep hole.

There is a simple Piaggio tool for installing this seal, like a drift which will allow you to seat the seal without damaging it, but I have had no luck finding the part number. You can fabricate this tool easily on a lathe from bar stock.

As a side note these seals ofttimes take up to 1500 miles to fully seat & seal.

A little weeping is not a problem if your coolant levels remain stable.

R

8)

Any chance that this post could be put in the wiki?

For the record, we use those type's of seals for high coolant pressure on machine tool applications and most of the instructions state " some seepage is normal. The seal is a ceramic disk against a hardened steel seat with a spring load. The seal gets its lubrication from this seepage. Also if you run one of those seals without coolant it will burn the seat and leak

some good info on these last few posts... sounds like i can just leave it alone and spend the money on a nice six pack to enjoy on a warm day.... well, with my current drinking skills, i can enjoy that six pack on six warm days!

Damn Stevie, its prob been a while since you enjoyed a beer, its been cold and rainy.

Your a cheap date.

Manny

You have the power...

Done.

My brain hates learning how to do new stuff.

https://modernvespa.com/forum/wiki-gts-gtv-water-pump-weep-hole

cheers

Hey; you get to the point where, if you want to force in something new, you have to force out something old (but known to be good).

At what pressure does the cooling system run before it vents, 12psi? Eventually, small leaks turn in to big leaks. Short of a service bulletin from Piaggio saying the condition is "normal" and what the remedy is when it becomes abnormal, any coolant loss should be closely watched. If the Dealer or Mechanic says "they all do that" it would be worth seeking an official explanation from Piaggio. What does the repair cost?

The coolant on a fully warmed up engine will be at 105C. That's under pressure...

The seal takes 1500 miles to seat. Then it starts to weep at 1600 miles. This is the Piaggio hemorrhoid. Sooner or later all water pumps get them. Leaves an ugly stain on the exhaust pipe but that's all.

Hi Guys,

I know this is a really old thread but I struggled to find any info on the web regarding the process to fit the water pump rebuild kit which included the ceramic seal.

Anyway, I've just done one on my wife's GTV 250 so I thought I'd pay it forward for the next newbie to suffer this fate. This would be a tricky job for anyone without access to at least a couple of tools but if you're half handy it would be practical.

If my memory is correct you will need the following tools:-

8,10,17 & 24mm O/E Ring Spanner
8mm Socket + ratchet handle & long extension
T40 Torx Driver or socket
#2 Phillips head screw driver
5mm allen key

Below are the step that I took to do the job, I made them up as I went along so use them as a guide only. Make sure the engine is cool before you start.

1. Put the bike up on it's centre stand, remove the RH side wheel trim & exhaust pipe. (make sure it's cold)
2. Drain the coolant by removing the 3 Phillips screws around the water pump cover. Have tray ready to catch the coolant. You can leave the cover attached to the hoses for this whole operation.
3. Remove the water pump impellor. This has a LH thread so you undo it clockwise.
4. Drain the oil (I used this as an excuse to change the oil & filter)
5. Remove the water pump cover. There is about a dozen screws holding it on. You'll have to disconnect the wire to the oil pump switch & stator cable as well.

By this time you should have the water pump housing out of the bike and sitting in you hands. The next steps I did on the bench.

6. Remove the stator from the housing and set aside.
7. Press the water pump drive shaft out of the housing. Press from the impellor side. I did this with a copper hammer as the kit I bought from SIP had a new shaft so I wasn't concerned with damaging it.
8. With the water pump shaft out of the way you should be able to push the old ceramic seal out with a drift of some sorts. Push from engine (oil) side of housing.

By now you should have the water pump housing stripped of all the old parts and have a basic bare casting in your hands. clean the bore where all the parts came out of and inspect for anything that may cause the seal/bearing not to seat properly. You can now see where the other end of the weep hole is. The next steps are the fun ones...

9. Using the pump seal drift (refer attached drawing) press the new ceramic seal into the housing. If you've made the drift correctly it should push on the moving face & fixed face at the same time by slightly compressing the seal spring. Test the fit before starting as this is very important to protect the seal when we push the drive shaft in.

10. Press the drive shaft adaptor bush (the one with the slot in it) onto the drive shaft. I did this cold in the press but was surprised how much force it took, it might be worth heating the bush up before you start instead.

11. THIS IS THE TRICKY BIT. You now press the drive shaft into the housing and ceramic seal. To support the seal from damage, use the pump seal drift as the anvil in your press. Lightly grease the shaft bore and hand fit the drive shaft. Once you happy and using both drifts press the assembly together. The pump shaft drift should be pushing on the outer race of the bearings, not the shaft. The driveshaft bottoms out in the housing so you can't really over fit this.

12. Fit the oil seal into the housing by hand using the pump shaft drift making sure you've got the pressure side of the seal facing into the engine.

By this stage you should have the all the water pump components except the impellor installed. You should be able to turn the shaft with your fingers but it should feel tight-ish (but not seized). This is because the ceramic seal has internal drag from it's sealing faces.

The rest is basically the reverse of the dis-assembly process so I won't go through it step by step. Here are a few things to be careful of:-

1. When you reinstall the stator components make sure the crank angle sensor's (the square plastic block held in with the two small screws) pin is properly located in the water pump housing as this ensures the alignment is correct. Get this wrong and you're likely that the engine will crank but not fire.

2. Mare sure you remember to fit the pump drive spring and align it in the two shafts. I chose to put it on to the engine side with a dob of grease and then installed the housing. You can get the housing within about 2mm of home then you just rotate the pump shaft with your fingers until you feel it engage.

Good Luck

+1
This is a well done write up. I don't think that I have Wiki access anymore but this should be added to it.