M1100s Caliper Torque

Hi,

I've become a bit paranoid about torque settings in my M1100s manual. It states 45NM for the front caliper mount bolts, bolts greased as well, is that correct? It also says 23 for the bleed nipple, which seems way to high, I always just nip them up.

Cheers

[chris.p]

45nm is standard for caliper bolts, always use a little copperslip myself.

[rollo22]

Best bet is to get your self a workshop guide has all the info you need including Torque settings.

[Luddite]

Both figures are correct.

The 23Nm is for the M10 threaded part which acts as the banjo bolt. The bleed nipple itself (which screws into the banjo bolt) should be torqued to only 4 Nm, i.e. just nipped up.

The recommended grease is molybdenum disulphide. Always apply grease if the manual shows it otherwise the torque wrench will click before you reach the recommended tightness.

Thanks all,

Just realised the 23 must be the banjo bolt.

Do you grease the thread and the underside of the bolt head?

Got a workshop manual, but they are known to have incorrect figures, e.g. the oil drain plug torque is much too high.

[TimDW]

Originally Posted by TonyG

Thanks all,

Just realised the 23 must be the banjo bolt.

Do you grease the thread and the underside of the bolt head?

Got a workshop manual, but they are known to have incorrect figures, e.g. the oil drain plug torque is much too high.

Grease the thread at the underside and it will spread out when you screw it in...

Most figures in the workshop manual are correct, some not, you're right (they are still Italians ). Most of the time just use common sense and think about the figures. That will help you out.

[Luddite]

Originally Posted by TonyG

Do you grease the thread and the underside of the bolt head?

Exactly! .

Once again, thanks.

It helps having forums like this. As I say, I've become a bit OCD about these things in my old age.

[Luddite]

Originally Posted by TonyG

Once again, thanks.

It helps having forums like this. As I say, I've become a bit OCD about these things in my old age.

Nothing wrong with that! Especially where your brakes are concerned.

[alan s4]

"The recommended grease is molybdenum disulphide. Always apply grease if the manual shows it otherwise the torque wrench will click before you reach the recommended tightness."

Every day a school day, didn't realise that, makes sense now that I think about it.

Thanks for all the advice.
As the weather was atrocious I did the work at the weekend. Front callipers all cleaned up, though they were in very good nick anyway, new fluid flushed through. Only thing I would say is the R clips seemed to be a bit of a sloppy fit, I was expecting more of a click as they went home. It's not like they wear out, anyway, all are fully home
Rear calliper was the same, lot dirtier due to its position. The calliper pin needed more force than I would expect to drive out, seems to be because it has a sort of barrel shaped collar at the end which locates in the calliper. I've never seen one like before. Also, previous owner had started to round off one of the mounting bolts. I was able to torque it up, but will probably replace later. Mind you, the back brake on this bike is the worst I have ever known, good job the front is excellent.

[Luddite]

Originally Posted by TonyG

Also, previous owner had started to round off one of the mounting bolts. I was able to torque it up, but will probably replace later. Mind you, the back brake on this bike is the worst I have ever known, good job the front is excellent.

The rear brake is well known for losing its effectiveness and will benefit from periodic bleeding. That's easier said than done though as you'll have noticed that the bleed nipple is on the bottom of the caliper and so it's very nearly impossible to remove all the air with the caliper in situ. I'd recommend unbolting it and flipping it over so it sits on the top if the disc like this:



Put some masking tape on the caliper first to protect the paintwork as it will rub against the swinging arm in this position. It won't slide fully onto the disc but it's enough to hold it in the right position to bleed it properly. You can see the bleed nipple is now at the highest point.

Once properly bled, it should be firm enough to lock the rear wheel.

I wouldn't try this until you've got a new caliper bolt though, your slightly rounded one might not stand up to another removal.

Surprised there is enough free play in the hose to achieve that. Will give it a go next time.

I didn't remove the wheel either, so it was all a bit more cramped to work on.

[slob]

Originally Posted by alan s4

"The recommended grease is molybdenum disulphide. Always apply grease if the manual shows it otherwise the torque wrench will click before you reach the recommended tightness."

Every day a school day, didn't realise that, makes sense now that I think about it.

The resistance to turning is provided by friction on the threads, so indicated torque is a measure of axial tension on the bolt.
If you lubricate the threads, you'll raise that tension applied for the same indicated torque and likely strip the thread or snap the bolt if it wasn't meant to be lubricated or as suggested above, fail to lubricate as indicated and the bolt will be under-tightened.
An oiled thread will produce around twice the the tension as a dry one for the same applied torque.

[emzedder]

Why lubricate the thread at all? I was taught to keep absolutely clean, only grease around bolt head or open thread to protect from elements. Similar head gaskets where grease can "boil" and cause leakage.