Topic: Need Torque Values for Brake Line Banjo Bolts

[bharvey60]

Hello all...

Anyone have the correct torque value?  I understand the heads can break off easily, but I found I had to tighten them down pretty hard in order to avoid leaking.

[Hinomaru]

Is this for your 750 K3?  If so, Honda terminology calls the brake line banjo bolts: "oil bolts". The CB750 shop manual supplement lists the brake oil bolt torque spec as:

kg-m  3.0 - 4.0 /  lbs-ft 21.7 - 28.6

(not to be confused with the oil drain bolts or oil filter center bolt)

[70CB750]

Thats helpful, i always do it the germanway - guttntight

BTW the unit in metric for torgue is Nm - Newton on meter lever. Does Honda use kgm?

[bharvey60]

Thanks Hinomaru. This was for the K3 "oil bolts".

[CycleRanger]

Hello all...

Anyone have the correct torque value?  I understand the heads can break off easily, but I found I had to tighten them down pretty hard in order to avoid leaking.

Always use a fresh washer/seal, they're really only made for single-use.

[Duke McDukiedook]

Thats helpful, i always do it the germanway - guttntight

BTW the unit in metric for torgue is Nm - Newton on meter lever. Does Honda use kgm?

No, that is a misprint, the modern metric units for torque are Newton Meters.

[MCRider]

Is this for your 750 K3?  If so, Honda terminology calls the brake line banjo bolts: "oil bolts". The CB750 shop manual supplement lists the brake oil bolt torque spec as:

kg-m  3.0 - 4.0 /  lbs-ft 21.7 - 28.6

(not to be confused with the oil drain bolts or oil filter center bolt)

I don't doubt that is what it says, but WOW, that's really high. That's higher than cylinder head nuts on hardened studs.

I put it in the category of "squishables". You tighten it till the washer/ORing squishes (drain plugs, spark plugs, tappet covers, oil filter bolts, brake banjo bolts) then a tad more. Run it, if it leaks, give it a tad more.

[Hinomaru]

MC, the torque spec is higher than I originally thought it would be also. Truth is, I have never paid any attention to the “oil bolt” torque spec until I looked it up for the OP. (good question, by the way) The info that I posted in reply #1 comes from my Honda shop manual w/supplements dated 1977. I’ve attached those images below. 

Perhaps we can compare specs to be 100% sure a discrepancy does not exist, what torque does your shop manual show?

Click on images for a larger view:

[MCRider]

Hino: My Clymers doesn't list it. But my goto chart confirms your numbers:
http://www.salocal.com/sohc/tech/torquetable.htm

Along with the "oil bolt" all my other "squishables" are pretty high torque values. For instance i would never take the oil drain plug to 25ft/lbs!

To each their own, I'll stick to my squishable rule, not because i am "right" but because it seems right to me.

PS: Oh look at that! My goto chart is the same as the one you posted.

Tappet hole cap at 10ft/lbs! No way!