thelastfz
New Member
Posts: 3
Registered: Feb 16, 2018 0:12:26 GMT -7
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Post by thelastfz on Feb 9, 2022 14:48:28 GMT -7
Hi all,
I'll try to keep this short...
A while back while riding I had my coolant reservoir overflow. bike still ran good, was not overheating so rode home then started to diagnose the symptoms.
once the bike was cool it had not pulled coolant back in from the reservoir.
I topped of the radiator and went for a ride, when I got back you could hear air coming out of the radiator cap and bubbling in the reservoir.
I thought head gasket possibly so I ran a, exhaust test with the color changing fluid... nothing
Pressure tested the coolant system for 10 min and it held with no drop.
Thought maybe the radiator cap was leaking and not drawing coolant back in so replaced that but still had same symptoms.
Finally a friend noticed a small amount of dried coolant coming from the weep hole in the water pump.
I guess the water pump was pulling air in past the mechanical seal under high load (revs)?
I don't really know but I replaced that and everything was all better. This all happened at around 20,000 miles
I am now at 29,000 and have the same symptoms.
I can hear air coming out and bubbling into the reservoir after a ride.
I'm thinking it is the water pump again but could there be something else causing it to fail?
When diagnosing the original problem I checked the functionality of the thermostat.
I could feel the radiator start heating up at 155 when it is supposed to open and a slow climb to 180 when it is fully open then it would heat up much faster till the fan kicked on.
Should the water pump be able to handle high revs even when the thermostat is closed?
After the first incident I was careful to not ride my bike hard till the temp was 160 or more.
I do ride my bike hard, lots of clutch slipping wheelies and redlining.
Most of my mechanic buddies say it should be able to handle.
just wanted to see if anyone else has had similar problems.
My thought is to replace the water pump again and gut the thermostat.
I know Samco makes a bypass kit but I did the silicone hoses with the last job and don't want to hand over another 300 for that kit.
If you're still reading this I appreciate it.
Please share your thoughts.
Thank you
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terrys
Full Member
Posts: 105
Likes: 80
Registered: Mar 1, 2021 0:48:28 GMT -7
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Post by terrys on Feb 9, 2022 20:10:23 GMT -7
The description of air bubbling into the reservoir sounds more like the coolant boiling in the engine and steam escaping into the reservoir. Assuming the temperature is not excessive (and I believe max allowable would be 120C/248F) then the reason for boiling is either coolant composition (too much water/not enough glycol) or a cap that won't hold pressure. I guess a pressure leak anywhere else would be the same as a leak from the cap, but usually a leak elsewhere is visually obvious with staining/wetting. Have you checked the surfaces in the filler neck where the cap needs to seal against for scoring or other damage that would affect the seal?
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Post by RedAndBlack on Feb 12, 2022 14:20:33 GMT -7
If you're getting coolant out of the weep hole in the coolant pump, it's my understanding that the seal on the coolant pump has failed. The problem with water pumps is that they move water really well, but they cannot move air. So what happens is that as they fail and air gets introduced into the system, air starts to build up in the pump and displaces water, not allowing the water to cycle through to bring cool air from the radiator and push out hot air from the engine. So coolant eventually starts to boil and steam off.
However, this should be coming from overflow tube or the radiator cap itself. I'm pretty perplexed with a situation of where coolant could be bubbling into the overflow tank. If I had to guess, it would be that air is being pushed out of the radiator which means there's a lot of air in the radiator that's being displaced by steam.
You definitely have some issues here as you're not even running hot temperatures. I run upwards of 220 in the West Coast Desert Heat through the canyons sometimes. The bikes can handle it.
If it were me and you're getting coolant from the weep hole, I would treat it like a failed coolant pump, replace it and the coolant. If you did it yourself, you're either unlucky or you might've messed something up. Maybe not completely purge the system of air.
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thelastfz
New Member
Posts: 3
Registered: Feb 16, 2018 0:12:26 GMT -7
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Post by thelastfz on Feb 15, 2022 15:42:49 GMT -7
Red and black, i think thats what happened. there is dried coolant coming from the weep hole in the water pump. what's funny is that even after it had boiled and created an air pocket in the system it still pulls coolant back in when it cools. i popped the rad cap and checked it out, filled to the brim. there was some build up around that area... it was hard white bits, almost looked like salt. I think this all stemmed from before it happened the first time when i did a coolant flush and used some low grade coolant from Napa. it was ethylene glycol but probably was the source of the problem. I changed the water pump then put the same coolant back in and after another 8k miles it happened again. Going to run some cleaner in the system and swap the water pump again then use the engine ice. and the cherry on top I noticed my left fork seal is leaking.  |
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