New purchase - shake down

2142 Views 10 Replies 7 Participants Last post by terry66, Mar 20, 2014

eviltwin

Discussion Starter · Feb 9, 2014

Hi there,

Just bought a 2005 Brutale 750 S, rode it back from Christchurch to Auckland (New Zealand) 1100kms of fast twisty roads to shake it down and see if there were any obvious issues.

1. Ran out of gas... got to use the trip meter huh.
2. Engine oil was low - do these bikes burn oil? I can't see any leaks.
3. Clutch weak - engages just off the handlebar.
I opened up the reservoir to check the fluid level, level looks good but the fluid is very viscous (thick) like engine oil - this does not look like Dot4 Brand Fluid which is very thin.
I topped up with Dot4 and the consistency was quite different and it did not seem to mix (like oil and water), I have drained all the fluid and will replace - any suggestions?

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vivere

· #2 · Feb 9, 2014

Welcome to this wondeful place. Any photos?

eviltwin said:
Hi there,

Just bought a 2005 Brutale 750 S, rode it back from Christchurch to Auckland (New Zealand) 1100kms of fast twisty roads to shake it down and see if there were any obvious issues.

1. Ran out of gas... got to use the trip meter huh.

Does have a fuel light, although on a journey like that you will need to plan your fuel stops..

2. Engine oil was low - do these bikes burn oil? I can't see any leaks.

I hate to be the one to ask the obvious question: you did check it correctly with the bike completely upright and not on the side stand?

3. Clutch weak - engages just off the handlebar.
I opened up the reservoir to check the fluid level, level looks good but the fluid is very viscous (thick) like engine oil - this does not look like Dot4 Brand Fluid which is very thin.
I topped up with Dot4 and the consistency was quite different and it did not seem to mix (like oil and water), I have drained all the fluid and will replace - any suggestions?

This doesn't sound right. Sounds like it may have water in it? Does the bike have a service history? I'd be checking and changing both of the brake fluids also...

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eviltwin

Discussion Starter · #3 · Feb 9, 2014

vivere said:
Welcome to this wondeful place. Any photos?

Cheers, I will put some photos up tonight

Does have a fuel light, although on a journey like that you will need to plan your fuel stops..

Yep it has a fuel light I just didn't know how far it would go on reserve...not as far as I thought huh!

I hate to be the one to ask the obvious question: you did check it correctly with the bike completely upright and not on the side stand?

Yep checked bike in upright position.

This doesn't sound right. Sounds like it may have water in it? Does the bike have a service history? I'd be checking and changing both of the brake fluids also...

Yep service history is regular till the last one, bike has done 22k, last service was Dec 13 seems looks like it was a valve check only, no record of oil change - I will replace oil filter and oil now to ensure it is a fresh start for me. And I will also drain and replace the brake fluid.

I have always used Motul RBF660 Dot4 Racing Brake Fluid in my bikes, I'm guessing this is ok for Clutch too.

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eviltwin

Discussion Starter · #4 · Feb 10, 2014

OK cannot get the clutch to pressurize, have tried for hours to bleed without success.
I drained all of the old fluid and have used a non return valve on the bleed valve but nothing is working
any suggestions other than taking it to the shop.

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gotojoe

· #5 · Feb 10, 2014

I would take the slave off and manually push the piston back.taking care that you protect the bike from hydraulic fluid. ..It would be useful to observe first if there is any fluid in there getting past the seal. If there is you'll need to pop the piston out and clean up then reseal it. Then rebleed.

These slave cylinders are so cheap on eBay in good used condition I wouldn't bother if the seal has gone I'd get another.

If you are feeling wealthy buy and OBeron Slave ..

joe

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revhead1957

· #6 · Feb 10, 2014

If you haven't found them already, there are manuals available for download on Donsy's website. The thread is a sticky in the maintenance section.
Looks like the bike has been sitting for a while, and prepped and light service for selling purposes? I would consider flushing coolant as well, and checking rear hub.

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theknurl

· #7 · Feb 11, 2014 (Edited)

eviltwin;

STOP

you need to flush the hydraulics on both the clutch and brake systems

it sounds like there is something other than DOT 4 brake fluid in your clutch system and maybe the brakes too

remove the slave, push the piston all the way in with a C-clamp and leave it

drain the M/C reservoir and wipe it clean with a lint free rag

lean the bike to the right and turn the bars to the right

refill the reservoir with fresh DOT 4 and bleed them the old fashioned way, without a check valve (sounds like its leaking air)

IF, after being bled correctly, the clutch engages just off the bar......somebody has fucked with the M/C piston push rod, see the manual for adjustment.....I'm not typing that much

then do the brakes the same way F/R before riding again......

it won't be my ass hitting the ground.....it might be your's

MVs don't use oil......neither does my Aprilia......now my R1150GS it sucks oil like a coke whore

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mitchy

· #8 · Feb 11, 2014

eviltwin said:
Hi there,

Just bought a 2005 Brutale 750 S, rode it back from Christchurch to Auckland (New Zealand) 1100kms of fast twisty roads to shake it down and see if there were any obvious issues.

1. Ran out of gas... got to use the trip meter huh.
2. Engine oil was low - do these bikes burn oil? I can't see any leaks.
3. Clutch weak - engages just off the handlebar.
I opened up the reservoir to check the fluid level, level looks good but the fluid is very viscous (thick) like engine oil - this does not look like Dot4 Brand Fluid which is very thin.
I topped up with Dot4 and the consistency was quite different and it did not seem to mix (like oil and water), I have drained all the fluid and will replace - any suggestions?

If someone has put oil instead of brake fluid in the reservoir and you have run it through the system,you will have to dissmantle the master/slave cylinders,clean (I use metho in these cases),fit new seals,flush the line with metho also and then bleed system with Dot 4 brake fluid.Did you buy the bike secondhand from a dealer? If you did,tell them you lost your clutch and get them to fix it.If oil has been added,a tell tale sign is the seal in the cap will swell larger than it's original size.The fluid could also be Dot 5 fluid which is a silicone based fluid which does not mix with Dot 4 or Dot 5.1.Which means all seals will have to be replaced now.

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eviltwin

Discussion Starter · #9 · Mar 2, 2014

OK, thanks for the feedback guys, very much appreciated.

After doing a bit of research it seems like the stock slave cylinder is a common issue on these bike.

Talking to the local MV dealer mechanic he said that most owners (here in New Zealand) have replaced the slave cylinder with an aftermarket one (Oberon).

Seems like the previous owner used a heavier fluid (oil, mineral perhaps) to attempt to band-aid the problem.

As 'Mitchy' said, if the rubber diaphragm comes in contact with oil it will expand in size - which is what has happened with mine. The fluid was thick, definitely oil not brake fluid.

I have ordered an STM slave cylinder (with bigger piston) from DesignCorse in the UK and a replacement rubber diaphragm.

The slave cylinder seals were not leaking, but I will flush the lines with methylated spirits (thanks Mitchy) - see if this solves the problem.

Cheers

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eviltwin

Discussion Starter · #10 · Mar 2, 2014

Are there any other faults with these bikes that I need to look out for?

I heard the Hubs can be problematic

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terry66

· #11 · Mar 20, 2014

Hi, you bought the one I wanted!! I looked at this one and ended up buying the one in Auckland, it had a few more Kms and was a bit tatty but the owner recovered the seat and dropped a thou off the price.
Its goes well and is going in for its 24, 000 service this weekend. Who are you using for servicing? Motohaus? Redbaron? I'm using Toby who was recommended by an Italian owners club member. Would be good to catch up and compare bikes. Good luck!!

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