Disassembly Dura Ace ST-7400 shifter ?

[jordic1968]

I've got a couple pairs but none in very good condition (working fine but with some scratches and chrome faults) so I was thinking to disasssembly and polish ... but looking at the diagram it seems specific tools are needed... Anyone has any experience with these levers ? Any advice ?

 

[jordic1968]

found this step by step guide:

https://imgur.com/a/4IT1J

Is this what you say "a piece of cake " ?

 

[bjarnetv]

its a bit fiddly, but not really that hard to disassemble the levers.
i would start out with detaching the lever from the main body, then moving on to removing the front cap and main brake lever.
if they work fine, i would just flush out the old grease and debris by bathing the entire assembly in degreaser.
if you need to dissasemble further, due to a loose spring or something - it's possible to remove the castle nut by using some thin needle nose pliers, unless you have the capacity to grind a custom tool.

 

[jordic1968]

Right, removing the lever is easy, and that allowed me to polish one part with nice results.

I was not sure if to remove the front cap I need the special tool, but reading your comment it seems not, so I'll give a it a try again. This is the other piece I need to sand the chrome and polish.

That will be enough to me. As the levers are working fine, just a lot of degrease and re-grease it all later on will be it.

thanks for the support and advice !

Here a pic after removing the lever , sanding the chrome and polish.

 

[bjarnetv]

just pop off the logo-button in front and unscrew the bolt holding the front piece in place and pull it off.
there is a spring in there so be ready for it.
after removing the front plate, you move the small lever over to the side and unscrew the single screw holding the main lever to the gearchange asembly.

 

[jordic1968]

yep, it worked ! -but I did not find the spring... maybe jumped off;(
Here it is the result, the front cap polished...

 

[bjarnetv]

yep, it worked ! -but I did not find the spring... maybe jumped off;(

better start looking, or the brake lever wont go back on it's own after changing gears :shock:
luckily its pretty big, so it should be easy to find.

 

[jordic1968]

polish done. Any trick to insert again this spring ????

 

[bjarnetv]

it's kind of hard to explain... but just insert the bent part of the spring in the sideways hole and align it, then press the lever forcefully into the main body at an angle to depress the pointy end where it should be and insert the pin quickly before everything explodes.

 

[jordic1968]

No way. I read now there is a special tool to assembly the return spring..... The pics are for 7800 series, but should be the same . Tried with a cable brake end but didn't work.