CBF1000

CBF1000 => General Maintenance, Servicing, and Mechanical => Topic started by: Gerry8888 on 08 October, 2020, 06:17:11 PM

Title: Coolant Issues
Post by: Gerry8888 on 08 October, 2020, 06:17:11 PM
Hi everybody, I have recently purchased a 2006 Honda CBF1000, I was in the process of washing it today and the coolant in the bottle started to bubble up and heat up, also it started leaking through a hose on the bottom of the engine.
Would anybody have any idea why this happened or if it is normal?
If not what can i do to fix it?
Thank you
Title: Re: Coolant Issues
Post by: Art on 08 October, 2020, 07:16:34 PM
Normal, check the coolant level when cold and don't leave the engine idling unnecessarily.
Title: Re: Coolant Issues
Post by: Gerry8888 on 08 October, 2020, 09:01:26 PM
Would that mean the coolant level is low? Also i brought it off for a 10 minute drive when i was finished washing it and the fan stayed on for entire time, is that normal aswell?
Title: Re: Coolant Issues
Post by: Crispy on 08 October, 2020, 09:30:16 PM
Boiling in the bottle, do you mean the white coolant reservoir underneath the seat?

My fan always comes on when I park up before opening the garage, itís probably because when youíre riding, the wind will air-cool the radiator and engine, to a degree. When you stop thereís no air cooling. How long did your fan stay on for? I would guess that longer than three minutes in autumn temperatures is too long.

Check in the morning for any leaks under the bike, remembering that being caught in rain or washing your bike will/can leave a puddle if it isnít dried properly.

Title: Re: Coolant Issues
Post by: Gerry8888 on 08 October, 2020, 09:39:44 PM
Yeah Crispy the white bottle under the seat, it was boiling away like a kettle!
I went for a 10 minute spin just around the block and the fan stayed on from when i left until i came back, and when i came back there was a small couple of drops coming out of the pipe on the bottom of the engine.
I only just bought the bike on Tuesday and never had this problem with any of my previous bikes.
Title: Re: Coolant Issues
Post by: Crispy on 08 October, 2020, 10:11:18 PM
My reservoir never boils, and doubt it ever should, all the time, if itís made of plastic. Iíd say itís definitely overheating, maybe because the coolant isnít circulating. The thermostat is stuck shut?
Title: Re: Coolant Issues
Post by: Gerry8888 on 08 October, 2020, 10:15:35 PM
Oh right ok how would i go about checking that out? Is it safe to drive at the moment if i top it up with coolant?
Title: Re: Coolant Issues
Post by: Crispy on 08 October, 2020, 10:25:57 PM
I wouldnít ride it if itís overheating. Use the search box on the forum and read the informative threads. The thermostat is on the right side under the tank. There will be a coolant pipe coming out of the thermostat towards the front wheel. If the pipe stays cold when the fan kicks in, the thermostat isnít working.
Title: Re: Coolant Issues
Post by: Gerry8888 on 08 October, 2020, 10:30:19 PM
Ok i will check that out in the morning thanks very much for your help i appreciate it
Title: Re: Coolant Issues
Post by: Shed on 08 October, 2020, 11:27:50 PM
No way is this normal, and in no way should your reservoir be 'boiling' or 'bubbling'. Ever.
Don't ride it out & about til you've sussed this out. Worst case, engine could be severely damaged if you continue riding it while its cooking itself into oblivion.

There's multiple reasons it could be, and plenty to check out. A few pointers...

Worst case scenario here is a blown head gasket/cracked head. If coolant leaks into one, or more, cylinders in the engine, the coolant will just be burned off, therefore you don't see any leaks or coolant on the ground as it's actually leaking internally. Or you can have combustion gasses being blown through a dodgy gasket into the water jacket of the engine, which then travel along to the reservoir, and this is what you are seeing as 'boiling' in the reservoir.

Check the oil. Any milky white oil on the dipstick/in the window?

But lets get the cheap & easy stuff checked first.  :028:

Take radiator cap off (when cold) - is the cap seal itself ok? Is the rubber seal ok? Does mechanism work? i.e. spring up & down? If the cap seal is knackered then excess pressure that would normally escape via here can't, so it finds another route out.

Does it have the correct amount of coolant in the system? Not enough? Is it definitely coolant you have in there? Coolant ratio correct? Is it 50/50 mix or thereabouts? If it's just water, or far too much water & not enough coolant, then the engine is easily going to overheat, hence it's actually steam bubbling its way along into the reservoir.

Check your coolant. Does the coolant look old/new/contaminated? Has the cooling system been filled properly?
Who put the coolant in? Mr Mechanic, or Mr Bean?
Do the hoses either side of the thermostat warm up? Check hoses for leaks. Check hoses for air locks.
Radiator clogged? Hose/s clogged? Is the water pump working? Check the thermostat. Stuck closed?

Fix your leaky hose. Is it definitely the hose, and not the water pump/seal itself?


Use this link, and us on the forum, to help you investigate:

https://bob.ollis-brown.co.uk/manuals/cbf1000/2006-2008-CBF1000-A-7%20COOLING%20SYSTEM.pdf






Title: Re: Coolant Issues
Post by: Art on 09 October, 2020, 01:09:17 AM
*Originally Posted by Gerry8888 [+]
Hi everybody, I have recently purchased a 2006 Honda CBF1000, I was in the process of washing it today and the coolant in the bottle started to bubble up and heat up, also it started leaking through a hose on the bottom of the engine.
Would anybody have any idea why this happened or if it is normal?
If not what can i do to fix it?
Thank you

Normal because I'm thinking its a wind up, how is it this can can happen when washing it?
Title: Re: Coolant Issues
Post by: Shed on 09 October, 2020, 07:44:39 AM
I'm thinking the washing it at the time is sheer coincidence. Coolant bubbling up at wash time (or any other time) isn't normal.
Also, his later post, reply #4 refers to the reservoir as "boiling away like a kettle".

Definitely not normal.


Gerry8888, is this bike from a shop? Warranty? Take it back.
Or is it a private buy?

(Also, further to what I wrote earlier, just note it is also possible to have a head gasket failure without any cross-contamination in the oil/water being blatantly evident, but hopefully we aren't needing to go down that route!).
Title: Re: Coolant Issues
Post by: Gerry8888 on 09 October, 2020, 09:29:17 AM
Ok i will check it out when i get home after lunch, the bike was purchased privately, it only has 26,000 kms on it!
With low mileage could it still be a cause for the head gasket/cracked head to happen? I really hope it is nothing serious or expensive
Title: Re: Coolant Issues
Post by: Shed on 09 October, 2020, 10:18:16 AM
Low mileage doesn't necessarily no problems. Depends how it's been maintained, and regardless, mechanical things fail - with or without human intervention  :127:

But before going down the road of doom & gloom, check out the stuff mentioned earlier and we can take it from there.  :028:
Title: Re: Coolant Issues
Post by: jm2 on 11 October, 2020, 02:33:49 PM
My first check there would be the radiator cap - is it on properly and is it working (both pressurising and releasing).

If it is truly boiling then you've no pressure in the cooling system (or so hot you've exceeded everything).
If it is air bubling through (the exp tank fills from the bottom) you may just be low on coolant (the bottom hose leak?) - but you can check this against the level marks on the exp. tank (mine has both hot and cold levels but it is usual to check cold - the minimum required)
Title: Re: Coolant Issues
Post by: Jimav on 12 October, 2020, 03:04:03 PM
I believe the same. If the spring of the radiator cap is loose, the the coolant will go to the plastic box even with low temp.
Plastic box never boils.
Title: Re: Coolant Issues
Post by: Gerry8888 on 16 October, 2020, 08:55:47 PM
Thanks for all your help guys, we took the bike apart and checked through a few options ye mentioned. It turns out the thermostat isn't working at all.
I have ordered a new one so waiting for that too arrive, so hopefully when we put it back together it will run as normal, i will keep ye updated.
Thanks again