# Shimano Hydraulic Road Disc Brakes. Hang Bike Upside Down?



## Russlite (Apr 12, 2009)

My new road bike features the Shimano 785 hydro disc brakes. I've heard that these brakes should not be stored upside down. I've owned several mountain bikes with hydro brakes and I've always hung these bikes from the ceiling in my garage. Seems like these should be no different. If you have air in your system what difference can it make how the bike is oriented while in storage? Thoughts?


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## jfaas (Jan 31, 2014)

Did it come with a statement from shimano? If shimano was aware of this happening they would have a statement warning you of improper storage. Their lawyers would make sure of it.


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## Russlite (Apr 12, 2009)

jfaas said:


> Did it come with a statement from shimano? If shimano was aware of this happening they would have a statement warning you of improper storage. Their lawyers would make sure of it.


Great point. I did not see anything in the manuals that came with the bike, but I should probably look again. My questions originates from gossip/rumors/scuttlebutt on the 'net. Always a good source of information


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## ibericb (Oct 28, 2014)

Here's Shimano's word on it (Dealer Manual, page 6):

_"When turning the bicycle upside down or on its side, the brake system may have some air bubbles inside the reservoir tank which are still there when the bleed screw is closed, or which accumulate in various parts of the brake system when it is used for long periods. This disc brake system is not designed to work with the bicycle upside down. If the bicycle is turned upside down or on its side, the air bubbles inside the reservoir tank may move in the direction of the calipers. If the bicycle is ridden in this condition, there is the danger that the brakes may not operate and a serious accident could occur. If the bicycle has been turned upside down or on its side, be sure to operate the brake lever a few times to check that the brakes operate normally before riding the bicycle. If the brakes do not operate normally, adjust them according to the following procedure."_​


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## ogre (Dec 16, 2005)

I've been hanging my Cx bike with 785 brakes for six months and no problems.


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## Russlite (Apr 12, 2009)

Thanks. That looks like lawyer talk to me  My bike has been laid on it's side many times while being transported in our camper. It has seen no ill effect from that. Still, it makes me wonder about hanging it in the garage.


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## jfaas (Jan 31, 2014)

Warning, pure speculation: I would think that if the brake lever was not activated while the bike was inverted, then the bubbles would not be able to leave the reservoir.


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## ibericb (Oct 28, 2014)

Russlite said:


> Thanks. That looks like lawyer talk to me  My bike has been laid on it's side many times while being transported in our camper. It has seen no ill effect from that. Still, it makes me wonder about hanging it in the garage.


All they allow is what "may" happen, with a caution about checking your brakes before riding. If bubbles go one way upside down, they should surely go the other way right side up. Doesn't sound like a big deal to me.


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## wgscott (Jul 14, 2013)

ibericb said:


> Here's Shimano's word on it (Dealer Manual,


That manual is much more comprehensive than the one I downloaded. Thanks for posting it.


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## ibericb (Oct 28, 2014)

wgscott said:


> That manual is much more comprehensive than the one I downloaded. Thanks for posting it.


You can get the dealer manuals for all of the current Shimano components here - just wade your way through the links.


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## wgscott (Jul 14, 2013)

I've got three different ones now, including yours. BR0004-00, BR0004-03, and BR0008-01.

I think they revised it when they added in the non-Di2 hydraulic brakes.


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## cxwrench (Nov 9, 2004)

If there is no air in the system, there is no air in the system. Hanging the bike any way you want will not introduce air into the system...not possible. 

But...

If the brake lines were cut and the system was bled improperly then yes...some air might not have been bled out and it could find it's way into spots that will cause problems. Pretty sure the Shimano dealer manual has that lawyer stuff in it for just this reason, they no doubt know that no matter how good your manuals are some 'less talented' mechanics will not do the job correctly.


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## wgscott (Jul 14, 2013)

My mountain bike brakes work fine until I turn the thing upside-down (it then takes like 10 or 15 squeezes to get it back to normal).

My road brakes are much more sensitive to the presence of air bubbles.


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## duriel (Oct 10, 2013)

Definitely do not hang a shimano mbike upside down, I had a problem with that.


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## ibericb (Oct 28, 2014)

duriel said:


> Definitely do not hang a shimano mbike upside down, I had a problem with that.


What kind of "problem" ?


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## ogre (Dec 16, 2005)

I've hung my bikes upside down in my garage for 18 years. Several MTBs and two hydraulic brake systems. I did have a Sid Race fork lose oil once, that's the only problem I ever had.


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## duriel (Oct 10, 2013)

My new shimano deore Mbike hydro, leaked and air got in the system upside down in my trailer. I'm guessing most of the fluid in the resivour got emptied out. I guess there would have been vibration while traveling. I had to get a new screw for the cover, maybe it fell out or I lost it pumping the system down, can't really remember exactly, but getting a new screw was a big problem.


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## TJay74 (Sep 9, 2012)

I hang our bikes from the front wheel with no issues. I hung my FIL MTB with the lower end Shimano disc brakes upside down and the rear brakes would go soft the bar, was bleed twice to no avail. Replaced the entire brake for the rear and figured it must be something with that system.


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## GRAVELBIKE (Sep 16, 2011)

What if I transport my bike from the US to Australia?


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## duriel (Oct 10, 2013)

GRAVELBIKE said:


> What if I transport my bike from the US to Australia?


I would recommend allowing time & research bike shops in the area or eq to bleed the systems if you have a problem.

Just needs attention, once I bleed the brakes and topped off the fluid it is fine. I was just out in the middle of nowhere when I discovered the issue.


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