need help on front brakes 82 xj750 seca

what do the little 3'' - 4'' brake hoses from the calipers go to and what does the part do for my brakes?

 

This is the part i`m asking about

 

They are brake lines that go from the caliper to the anti-dive valve.

 

As for what they do... nothing for the brakes, per se, but, when you engage the front brake, they also actuate valves in the bottoms of the forks that makes them stiffer, so they don't collapse (dive) under hard breaking.

That's the theory, anyway. Many people say they're overcomplicated, some people say they don't work, and, as easily as the internal parts are damaged, I wouldn't be surprised if a lot of them don't work as well as they did when new due to damage to those small parts while changing fork seals.

 

thanks my bike had been sitting for sometime before i got it brakes were stuck on removed calipers pressed pistons in sides were stuck cleaned and lubed reinstalled bled lines worked for 3 days now stuck again pistons pressed in fine , i`m kinda stuck thinking i my have a bad brake caliper hoses

 

If you have original lines, it's a good idea to replace them anyway. Len has a number of options there, including braided stainless steel. Paragon Products also has a stainless steel set for this bike.

 

They barely work. My bike still has some nose dive, but it isn't jerky, it's very predictable and you can get on the brakes pretty good. I have stock springs and 15 weight oil though, I bet with progressives and 20 weight it would hardly dive.
Get SS lines, my bike barely stopped and had spongy brakes and the anti dive didn't work before I got SS lines.

 

Search this site on post by Rick CoMatic, his advise on unsticking these calipers is excellent.

Inside the break caliper, focus in on the grove for the piston seals. They must be zestfully clean, no residue at all. If their is any gunk, the seal will bulge and the piston will jam.

Also pay real close attn to the spindles / large pins that hold in the pads and the caliber to the mount. both need to be mirror finish as well as bores where they move with in the caliper.

 

thanks for your help Gehiv will check it out