Topic: 76 550F - No mount on lower for three way brake switch?

[AllGasNoBrake]

Tried searching high and low but it gets called so many different names I couldn't find anything.

Putting back together this bike that someone else disassembled and I went to mount the three way switch/oil switch/splitter and there's no hole on the lower yolk to bolt it to like I see in schematics and photos. My lower is smooth with no flat spot to mount like I see in some pics. Am I missing something here or is there a piece that attaches which it bolts onto?

Follow up question, best place to buy crush washers for attaching the lines?

[goodtryer]

With a user name like yours, I figured you’d be the one cutting off brake parts. 

For crush washers, look on Amazon. You can find variety kits with a hundred or more pieces in various sizes, metric and standard, copper and aluminum.

Cheers

[bryanj]

10mm copper washers and its probablyhad the wrong lower yoke(tree) fitted

[Bodi]

"best place to buy crush washers for attaching the lines?"
Almost any bike shop?

[pekingduck]

Well, that is a puzzler.  Since it was taken apart by someone else, it very possibly is a different stem.  Is the flat boss there?   Is there possibly a hole drilled on the underside for an "L" bracket.  It seems I recall seeing that on some model, but not sure.

Also, is there a hole for a steering lock?  Super Sports and all '77/78 550/750s wouldn't have one.
Only the 450/500 DOHC twins and CB500/550/750 SOHC fours had 35mm forks, and all of those before 1975 had the steering lock hole. 

CB650s and DOHC fours had different stems.  The 3-way junction was eliminated starting around '78 because the master cylinder had a mechanical brake switch.

How about a picture, with the matching top clamp, to help figure this out.

[AllGasNoBrake]

With a user name like yours, I figured you’d be the one cutting off brake parts. 

For crush washers, look on Amazon. You can find variety kits with a hundred or more pieces in various sizes, metric and standard, copper and aluminum.

Cheers

I'll update my name when I get this sorted out 

Thanks for the washer recommendations. Ordered a set of assorted copper washers.

Well, that is a puzzler.  Since it was taken apart by someone else, it very possibly is a different stem.  Is the flat boss there?   Is there possibly a hole drilled on the underside for an "L" bracket.  It seems I recall seeing that on some model, but not sure.

Also, is there a hole for a steering lock?  Super Sports and all '77/78 550/750s wouldn't have one.
Only the 450/500 DOHC twins and CB500/550/750 SOHC fours had 35mm forks, and all of those before 1975 had the steering lock hole. 

CB650s and DOHC fours had different stems.  The 3-way junction was eliminated starting around '78 because the master cylinder had a mechanical brake switch.

How about a picture, with the matching top clamp, to help figure this out.

Not sure if that shows enough to identify it. I swear in some Google search I saw something about the 550F in certain years having this joint relocated but didn't find it on the page to confirm. There is one bolt located underneath the lower yoke pointing upwards, but it is larger than the hole on the joint to attach it (in pic below).

[pekingduck]

Looks like your stock stem has been modified by welding up the bolt hole and grinding down the boss.  just need to re-drill it.

[Don R]

 If you don't mind the look, you can get a brake light switch that goes on the M/C in place of the banjo bolt and run a custom brake hose straight from the M/C to the caliper.
   I'm sure someone here knows the application for the brake light switch or run a right control from a bike that has a switch built in.

[kerryb]

'78 cb750k  brake lever and master cylinder looks just like what was on there with the addition of a brake switch which will plug right into your harness.  Another option is a replacement mc with a brake switch from 4 into 1 that is also 14mm bore.  Either one of those means new hoses or a junction to join the existing hoses.  It might be less costly to modify or replace the tripple trees.

[AllGasNoBrake]

Looks like your stock stem has been modified by welding up the bolt hole and grinding down the boss.  just need to re-drill it.

Amazing detective work, thank you! Not sure why they would do that, but I've said that more than a few times working on this project..

[AllGasNoBrake]

If you don't mind the look, you can get a brake light switch that goes on the M/C in place of the banjo bolt and run a custom brake hose straight from the M/C to the caliper.
   I'm sure someone here knows the application for the brake light switch or run a right control from a bike that has a switch built in.

'78 cb750k  brake lever and master cylinder looks just like what was on there with the addition of a brake switch which will plug right into your harness.  Another option is a replacement mc with a brake switch from 4 into 1 that is also 14mm bore.  Either one of those means new hoses or a junction to join the existing hoses.  It might be less costly to modify or replace the tripple trees.

Good ideas. I replaced the M/C and levers with 4into1 satin black cafe style levers and already ordered a new hydraulic switch after testing the original one. Had I known I would have just ordered a brake lever with the switch built in. I'm debating tapping a new hole back into the original location or possibly mounting the 3-way where the horn location as seen here, but I'm concerned that would bring the line closer to the header and expose it to more heat.

[pekingduck]

Well, if you're not mounting the brake hose junction there, it certainly looks a lot cleaner. 

I wouldn't recommend mounting it on the frame - it should move with steering.  You can always bolt a bracket from the steering damper hole at the right rear under the triple clamp to the front.