XJ750R Anti Dive System

After purchasing an XJ750R a few weeks ago, I've been working hard to make it safe and reliable. At this point, everything is fixed with the exception of the front brakes.

I tore into them this weekend and discovered that the calipers were tight because the system didn't seem to be allowing the pressure to release. No big deal. I assumed the whole system probably needed a good cleaning so I ripped it all out. I think the piston in the master cylinder is shot so I ordered a rebuild kit from OldBikeBarn.

I then realized that something seemed strange though. I had been reading about the anti-dive mechanism on these bikes and couldn't figure out how it works. I couldn't figure out how it was connected to the brake system to save my life.

Thank goodness for the XJ Cds. I found a diagram and realized that the hoses that connect the calipers to the anti-dive mechanism are missing! It looks like some previous owner just took them off.

So here's my question. Once I get the master cylinder rebuilt and get the brakes working, is it safe to leave that system inoperable? I rode the bike home 40 miles and it seemed ok, with the exception of the calipers sticking. There must be oil in the forks because the seals are weeping a little bit. I'd love to restore the anti-dive mechanism, but I can't find those darned hoses for sale anywhere.

Your thoughts?

Greg

 

I don't think you would have any trouble riding the bike without the system personally. All it does is provide brake pressure to the valve to help adjust the anti-dive valve to the right proportion based upon how hard your braking. I'm sure the piston/spool in the anti-dives will simply be pressurized up against the bottom of the cylinder and should not interfere with anything. You can sit down with some braided stainless steel and whip up a trick pair of lines in about an hour. Might as well make a complete system while your there. Alternative is to hit flea-bay and score a set of lines. Worst case someone on the forum can photograph theirs and send you pics and length measurements. Hope someone is local to you, you could have them drop by and show off their system. Best of luck to you.

 

I can see how the hoses work, but I can't see how one would make a pair. Where do you get that kind of end? -- The ones that the banjo bolt goes through. I'd be happy to try my hand at making a pair if I can get the parts.

Thanks,

Greg

 

TRy the wreckers , also as wizz says its no trouble to leave them disconnected..

As if you get the hoses they might not work [twas probably why they were removed] , so if you are going to do the hoses i suggest a pull apart of the antidive units/clean inspect and new o rings....

 

You can source the parts from just about any line manufacturer, Russel, Earl's, Aeroquip, just to name a few. You will need pictures of the fittings that you need but the dimensions are standard metric hardware. Good bike shop can hook you up. Check with Galper, they make lines for bikes, I've a nice set for my turbo front end, three lines $100.

 

Thanks for the info Robert. I will look into making my own.

What Turbo front end are you reffering to? You didn't get a Seca Turbo when I wasn't looking did you?

Greg

 

No Greg (I wish), I scored the entire front end off of an LJ, with rims, from a nice fellow out in Vancouver(?).