Coolant change and flush disaster

[MadMarc]

I like to do what servicing I can and I'm usually quite competent with regular work. Oil, coolant, brake pads, filters, that kind of stuff. Occasionally I come a cropper as I did today. I'm doing a TET trip in September so giving the bike a good service. I got around to the coolant and decided to use radiator flush too. It says bring engine up to operating temperature for half an hour. So rather than have it idle and switch itself off I went for a spin. Anyhow at a junction I noticed fluid leaking onto my boot. I kept an eye on the temperature and nursed her home. Turns out it was coming out of the weep hole behind the water pump. For a second I thought I'd killed the engine. Anyhow I put the fresh fluid in after draining the rad flush stuff and miracle of miracles it seems to be staying in. I didn't want to leave it empty with reside of the flush in as it's highly corrosive alkaline? This corrosive Shet was all over everything so needed a good wash off some still adhered to the front exhaust. Even if this fresh coolant does stay in I'm guessing I'll need a new water pump. Anyone familiar with weep holes can anyone explain why it didn't hold the flush liquid but is holding the coolant? Manthorpe thanks.

[Just Footerin]

Hmmm, funny one. There's a mechanical seal in the waterpump housing. They are available as I've managed to source one for an old XTZ Tenere.  For water to come out the weep hole it would have to get past this seal, (so water drips out the hole and not into your engine),  maybe the flush lifted something that somehow got trapped in the face of the seal and now its gone ??

 

 Personally I don't think you would have needed to add that flush, the coolant and radiator usually stay pretty clean, a blast through with the garden hose would have perhaps done ?  You'll just have to keep an eye on it for a while

 

 

Edited July 11 by Just Footerin
typo

[SXXP]

18 minutes ago, Just Footerin said:

a blast through with the garden hose would have perhaps done ? 

 

Flushing with a gallon or two of distilled water purchased from the local grocery store would have been my choice, but to each his/her own

 

Edited July 11 by SXXP

[Samm]

I’ve never used a coolant flush so I’m probably talking out of my a$$ here but I agree with Just Footerin. Maybe overheating the flush chemical caused the pump seal to swell or something.
 

You’ve removed the chemical and replaced the coolant and the seal is holding but if it were me I would drain the system, pull off the pump cover and do a good inspection and replace the seal. In my mind, if fluid got past the seal once it can happen again. The low cost of a seal and some coolant will give you peace of mind on your TET trip. 

[Just Footerin]

@SXXP interesting topic. I don't want to divert from @MadMarc 's post, but as I've heard others mention use of distilled water in radiators, please let me say this. I work as an engineering tech in a pharmaceutical company making intravenous solutions. We distill water down to virtually zero micro siemen so it can be used as water for injection (WFI). However we don't use this water in any of our factory chiller units (radiators) as it's been proven to destroy the cores over time. Instead we use plain old mains tap water, usually without any glycol !

Certainly as you say, using it to flush with wont do any harm as its not going to stay in the radiator, but I would NOT recommend people use distilled water to dilute a concentrated glycol mix. That will destroy your radiator over time.  Just buy a premix brand. 

 

Edited July 11 by Just Footerin
typo

[Tenerider]

Agree with @Just Footerin and @Samm. An aggressive chemical can destroy seals - and if it has a much lower viscosity compared to coolant, it might leak easier. I'd also replace the seal.

 

BTW, are you the RM250 restorer from YT?

[MadMarc]

2 minutes ago, Tenerider said:

Agree with @Just Footerin and @Samm. An aggressive chemical can destroy seals - and if it has a much lower viscosity compared to coolant, it might leak easier. I'd also replace the seal.

 

BTW, are you the RM250 restorer from YT?

No I'm not. Is the seal to be replaced just the rubber ring type seal that sits in the groove around the edge of the housing? Isn't there another seal where the rotor part of the pump is that wears with the friction of use. If this seal is failing is it easier to replace the water pump entirely or can it be overhauled?

[Samm]

You should be able to overhaul. For the cost difference between the seal and the whole pump, I would attempt the seal. 
 

Yamaha 5VK-12438-00-00 - MECHANICAL SEAL | Partzilla.com

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Buy Yamaha 5VK-12438-00-00 - MECHANICAL SEAL. This OEM part is guaranteed by Yamaha's limited part warranty ✓ FREE Shipping on qualified orders - Partzilla.com

 

 

[MadMarc]

12 minutes ago, Samm said:

I’ve never used a coolant flush so I’m probably talking out of my a$$ here but I agree with Just Footerin. Maybe overheating the flush chemical caused the pump seal to swell or something.
 

You’ve removed the chemical and replaced the coolant and the seal is holding but if it were me I would drain the system, pull off the pump cover and do a good inspection and replace the seal. In my mind, if fluid got past the seal once it can happen again. The low cost of a seal and some coolant will give you peace of mind on your TET trip. 

I agree. I haven't been able to see this seal for sale. Maybe I'm doing the wrong searches. I certainly won't be so anal in my coolant replacement in future. Is the seal an easy fit? I'm guessing it's not just the o ring type seal on the outer part of the housing. I was amazed to discover the weep hole, for a sec (I was a bit hyper after limping her home) I thought I'd got a bike with a bad casting. Then I noticed the grooves in the hole and realised it was integral. So cheap seal fix or replace pump?

[MadMarc]

5 minutes ago, Samm said:

You should be able to overhaul. For the cost difference between the seal and the whole pump, I would attempt the seal. 
 

Yamaha 5VK-12438-00-00 - MECHANICAL SEAL | Partzilla.com

---

Buy Yamaha 5VK-12438-00-00 - MECHANICAL SEAL. This OEM part is guaranteed by Yamaha's limited part warranty ✓ FREE Shipping on qualified orders - Partzilla.com

 

 

Thank you so much. I'll try to get my local Yamaha dealer to ship it tomorrow, rather than ordering from over the pond. 

[Just Footerin]

@MadMarc I think your describing an o-ring.  The mechanical seal is a two part seal with very hard carbide like faces. A little spring keeps pressure on the two faces, maintaining the seal.  I'll look into it a little for you. When I done the old bike I remember Yamaha don't list it as a spare, but I got one from somewhere. I think I have a photo on my phone if I can find it.  I haven't actually encountered any trouble from my new T700 but I imagine this is all similar stuff.

[SXXP]

34 minutes ago, Just Footerin said:

@SXXP interesting topic. I don't want to divert from @MadMarc 's post, but as I've heard others mention use of distilled water in radiators, please let me say this. I work as an engineering tech in a pharmaceutical company making intravenous solutions. We distill water down to virtually zero micro siemen so it can be used as water for injection (WFI). However we don't use this water in any of our factory chiller units (radiators) as it's been proven to destroy the cores over time. Instead we use plain old mains tap water, usually without any glycol !

Certainly as you say, using it to flush with wont do any harm as its not going to stay in the radiator, but I would NOT recommend people use distilled water to dilute a concentrated glycol mix. That will destroy your radiator over time.  Just buy a premix brand. 

 

 

Interesting!  I have, over the past 40 years or so, always flushed my vehicles with distilled water, and then made a 50:50 mix of of coolant/distilled water to refill.  I've NEVER had an issue with my cooling systems.  My now beater car, a 2008 Honda Civic that I have owned since new, that I use on a daily basis for my 100 mile round trip commute, now has a tick under 300K miles - will reach that milestone by year end - is still on the original radiator and water pump and has never over heated.

 

Same with my motos.  The oldest is a 95 Kawi Gpz 1100 which only has 38K miles, but also flushed with distilled water and then refilled with a 50:50 mix of appropriate coolant and distilled  water over the years.   

 

BTW, it's cheaper to buy the concentrate here, so I always go that route, and dilute to a 50:50 mix.

 

Also, the hardness of tap water varies by city depending on their source, and to me that's a radiator waiting to be clogged with scales over time.   The water in one city I lived in for ten years always left nasty water spots around kitchen appliances if not wiped down religiously.  I would never even think of introducing that water into my radiators.

 

YMMV.

 

 

Edited July 11 by SXXP

[Just Footerin]

https://www.ebay.co.uk/itm/145125261813?gad_source=1&mkevt=1&mkcid=1&mkrid=710-53481-19255-0&campid=5338723872&toolid=20006&customid=StNxk3AfAAAAnEoek25eiqVOSSA6AAAAAA

 

says its for an MT-07 but it might be the same. Keep searching.

[Samm]

Depends what you’re comfortable doing.

 

Before ordering parts take a look at the manual and make sure you’re willing to attempt the fix.

To replace the seal you need to pull off the clutch cover, which means draining the oil (unless you’re ok just laying the bike over so you don’t spill any). The impeller shaft goes through the clutch cover and is held on with a circlip. Pull off the circlip and you should be able to slide the impeller out exposing the seal in question. Pull that out and make sure the oil seal behind it is good (not a bad idea to have one of those on hand as well in case you damage it trying to remove the outer seal). Manual shows a special tool for installing the new outer seal but you can probably make do with a makeshift deal driver using threaded rod, assorted washers, sockets etc…

 

Looks like the impeller seal is $40 USD, inner oil seal is $8 (2CR-13338) and the entire pump assembly is $250 (1WS-12420-01)

[Samm]

 

[Samm]

And just to get you second guessing yourself after saying all of that…

 

“If it ain’t broke, don’t fix it” is still an option.
 

No coolant out of your weep hole means the impeller seal is good and no oil through your weep hole means the oil seal is good…as long as the weep hole isn’t plugged with anything…

[MadMarc]

I guy at work suggest running as is and keeping an eye on it. I just don't want to be fretting about it on the dusty TET tracks in Portugal and Spain come September.

[Just Footerin]

You'll be grand, even if it did start dripping while your away, I doubt if you'll lose that much over a day. Buy a bottle of water and keep it topped up til' you get home  .  

(TIP - leave out that tiny security screw from your radiator cap. you don't need to be looking for a tiny allen key when your on the road. )

But let us all know if it gives any more issues before you go. 

Edited July 12 by Just Footerin

[Dan M]

Coolant flushes contain citric acid. I'm wondering if it somehow caused the seal to weep.  Coolant contains lubricants specifically for the seal. 

It sounds like the new coolant did it's job and you are in good shape.

 

If a vehicle had another issue contaminating the coolant, chemical flushing is recommended.

If the old coolant is in good condition - no discoloring, oil contamination or rust - I wouldn't use any flush.   Drain & fill is all that's needed.

Edited July 12 by Dan M