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Discussion Starter · #1 ·
Hi all
My Brutale 800 euro 4 is having a pee on the road after about a10 mile run - bike is fairly new to me and this is the warmest weather its been in with me, only low 20s centigrade about 72 F to you guys on the other side of the sea!!
Checked this forum seems like there may be a batch of faulty rad caps releasing the pressure causing overheating - anyway ordered a new one from Evolution (shipping almost as much as the cap!).
My local MV dealer - about a and hour and a bit ride quoted 7 - 10 days so see what Evolution manage - I will update!

Has anyone got any other experience with this - rad was boiling, fan working, no faults showing (that I noticed - shut it off quite quickly before I damaged anything), expansion tank empty, rad full and clean green / blue coolant.

I have closed the cap clasps up a bit to tighten the grip - will top up with water and give it a test

Cheers Graham
 

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Graham, could you see/hear the coolant boiling?

If so, then you are on the right track. You should also probably inspect and clean the sealing surfaces of your pressure cap.
 

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Discussion Starter · #3 ·
Thanks Chuck
Yes definitely boiling - cleaned the cap and the seals but not really that dirty apart from what looked and felt like a bit of grease build up on the spring.

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Hmmm, the seal area looks a bit pitted perhaps a clean up with ultra fine scotch brute is in order.
I鈥檇 also look for other minor leaks and exercise the spring and seal on the cap. Otherwise, a new cap is probably the solution.
 
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You can get a 1.6 BAR cap if you wanted. Radiator caps are not expensive..
 

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Discussion Starter · #6 ·
Not keen on putting a higher pressure cap on - if the cap is not the fault but just doing its job as high pressure relief is it possible damage could be caused elsewhere? Please correct me if I'm wrong.
 

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Your system can contain the higher pressure with no problem.
Lots of off road guys install higher pressure caps to prevent boil over, as their bikes have no fan.
The newer Kawasaki ZX10Rs use a higher pressure cap so they can run hotter engine temps (more power = more heat).
But your cap looks knackered...I'd try a new one.
A good radiator tester can also test the cap....do you have a friend with a cooling system pressure tester ? Automotive mechanic maybe?
 

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Discussion Starter · #8 ·
Ok cheers - new MV cap on order - I'm pretty sure the old ones had it.
Interesting about the higher temperatures increasing power - why don't we all do that there must be a downside?
Yes my local garage will have a tester they will let me use or test it probably foc for me.
I cleaned the cap and bent the clips over a bit - run it up to temperature on tickover with no issues.
Graham
 

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Interesting about the higher temperatures increasing power - why don't we all do that there must be a downside?
Other way around... you make more power and the result will be more heat. Internal Combustion Engines make more BTUs when they make more HP
 
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Ok cheers - new MV cap on order - I'm pretty sure the old ones had it.
Interesting about the higher temperatures increasing power - why don't we all do that there must be a downside?
Yes my local garage will have a tester they will let me use or test it probably foc for me.
I cleaned the cap and bent the clips over a bit - run it up to temperature on tickover with no issues.
Graham
The cap is a standard automotive fitment if you want try your local parts supplier or radiator specialist who will have it at a fraction of the price.
 

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Discussion Starter · #11 ·
New MV one due for delivery today - 5 days from Italy to UK - I'll update later when tested!
 
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