overflow coolant leak

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redman412
Posts: 14
Joined: Wed Dec 19, 2012 6:06 pm
Location: New York city

overflow coolant leak

#1 Post by redman412 » Sat Jul 15, 2017 10:48 pm

Took a ride to test my bike as the weather wasnt scorching. Coming from a stop and go traffic and getting a free flow highway for 20 minutes stop in front of my garage to put the bike inside, I noticed coolant dripping from the left side of the bike. Took the left side side cover on the overflow tank, bottle was full and pop the top of the bottle. I got an aluminum Radiator 4 years ago, a new thermostat and a new metal impeller from Economycycle. Could my thermostat gone bad in 4 years? Rad cap is the original Yamaha. Any ideas guys? Bike was hard to shift when really hot, never had a problem before the rebuild from Wicked. Hope he didnt take my impeller and toss it out, and replaced with some crappy one.

tacky1
Posts: 950
Joined: Wed May 13, 2015 1:11 am
Location: Pacifica,,

Re: overflow coolant leak

#2 Post by tacky1 » Sat Jul 15, 2017 11:49 pm

Mine did the same thing last year, Head gasket failed, I wasn't using an OEM head gasket, Cleaned up the head, bought an OEM gasket and it fixed my problem
1985 RZv500
1984 RZ500 Hybrid
1986 RG500 Walter Wolf
1986 RG500 Skoal Bandit
1984 RZ350
1984 RZ350 Hybrid
1981 RD350LC
1981 RD350LC Hybrid
2009 CR500AF Supermoto 250X
2007 CR500AF 250X
1988 YSR50 (2)
1984 GPZ750 Turbo
1989 VFR750R RC30

redman412
Posts: 14
Joined: Wed Dec 19, 2012 6:06 pm
Location: New York city

Re: overflow coolant leak

#3 Post by redman412 » Sun Jul 16, 2017 2:36 pm

Really? Head gasket failure? Better go to the Yamaha dealer see if I can buy one and replace it.

AlexG
Posts: 35
Joined: Sun Jul 31, 2016 8:32 am

Re: overflow coolant leak

#4 Post by AlexG » Sun Jul 16, 2017 2:50 pm

Hi:
If the temperature gauge was OK during the ride, it could be that you just stop the thing from everything super hot to no cooling at all, and the thermal inertia of the whole system expanded the refrigerant beyond the ability of the tank to contain. However, concerning is that the cap of the tank was popped; it could be the head gasket leaking combustion gas into the coolant chambers; not unusual. Way to be sure is to have a gas analyzer sniffing the radiator cap, as it should detect hydrocarbons right away. Another way is to observe if there are small bubbles reaching the top of the radiator at the cap location.

AlexG

(F5)
Posts: 630
Joined: Mon Sep 27, 2010 7:21 pm
Location: Wellington New Zealand

Re: overflow coolant leak

#5 Post by (F5) » Sun Jul 16, 2017 4:30 pm

Been there done that. Genuine Yamaha head gasket in your future.
496 Cheetah. TSS PVs, PWK35s, Ignitech, RGV(ish) chassis

tacky1
Posts: 950
Joined: Wed May 13, 2015 1:11 am
Location: Pacifica,,

Re: overflow coolant leak

#6 Post by tacky1 » Sun Jul 16, 2017 6:16 pm

redman412 wrote:Really? Head gasket failure? Better go to the Yamaha dealer see if I can buy one and replace it.
I would check a few items before plunging into the head gasket, Proper rated rad cap is a biggie, thermostat, impeller. Make sure it actually is circulating the coolant.
Mine went into the red before it puked the coolant.
1985 RZv500
1984 RZ500 Hybrid
1986 RG500 Walter Wolf
1986 RG500 Skoal Bandit
1984 RZ350
1984 RZ350 Hybrid
1981 RD350LC
1981 RD350LC Hybrid
2009 CR500AF Supermoto 250X
2007 CR500AF 250X
1988 YSR50 (2)
1984 GPZ750 Turbo
1989 VFR750R RC30

redman412
Posts: 14
Joined: Wed Dec 19, 2012 6:06 pm
Location: New York city

Re: overflow coolant leak

#7 Post by redman412 » Mon Jul 17, 2017 12:17 pm

im ordering a new thermostat and rad cap. Ill check the impeller as is brand new metal one from economy. What a PITA!!!

silverstrom
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Joined: Wed Mar 24, 2010 2:20 am

Re: overflow coolant leak

#8 Post by silverstrom » Mon Jul 17, 2017 1:21 pm

It's unlikely your impeller has failed.

The first thing I'd do is pull the clutch cover and make sure the plastic drive gear is still good and properly attached to the impeller shaft.

tacky1
Posts: 950
Joined: Wed May 13, 2015 1:11 am
Location: Pacifica,,

Re: overflow coolant leak

#9 Post by tacky1 » Mon Jul 17, 2017 3:27 pm

I have seen an impeller separate from the shaft on one of my old Banshees, I was using an aftermarket one, Id check it as well as the gear on the back as John recommends..
1985 RZv500
1984 RZ500 Hybrid
1986 RG500 Walter Wolf
1986 RG500 Skoal Bandit
1984 RZ350
1984 RZ350 Hybrid
1981 RD350LC
1981 RD350LC Hybrid
2009 CR500AF Supermoto 250X
2007 CR500AF 250X
1988 YSR50 (2)
1984 GPZ750 Turbo
1989 VFR750R RC30

silverstrom
Moderator
Moderator
Posts: 7030
Joined: Wed Mar 24, 2010 2:20 am

Re: overflow coolant leak

#10 Post by silverstrom » Mon Jul 17, 2017 4:58 pm

You're right Paul. Nothing is impossible. I've seen some bizarre things fail over the years.

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