1993 cbr1000f rear brakes
 

i just bought a 1993 cbr1000f and the rear brakes dont work at all it says linked braking system and idk where to start so i dont know if there are common probs with this or what so if any tips are out there please help on where to start

When you say "the rear brakes don't work at all" does the pedal feel normal (like it's making pressure)? If the bike hasn't been used for ages maybe the pistons in the rear calipers have stuck. Could be the rear master cylinder is stuffed too. I'd start by flushing the brake system with new fluid and bleeding then go from there. Then you'll be able to see if the master is pumping properly. Next would be to pull the back caliper off and go in. There's a manual to download on this site which will tell you the ridiculously complicated bleeding procedure for the linked system.


imo the linked system sucks and I had mine split. I couldn't drag the back brake around small roundabouts or slow riding without the front brake coming on suddenly and the front trying to tuck in under me.

We might be able to help you after you answer davethepom's questions and suggestions. You definitely need to get your hands on some material on how those brakes work which will help you diagnose the problem. There are a couple of simple tests you can do to check them.

rear brakes
 

When I push down on brake pedal there is no pressure at all it just goes down I have plennty of fluid so idk

See if you can download a manual. Gonna send you a private message with my phone number. Call me and I may be able to walk you through a few of the above mentioned items to get you started.

Malbojah is another resident expert, as is Dean0.
If Ronnie can't help (Hi Ronnie) I'm sure that one of them will. There's also a how to on it I think....:)
This I know, that there's a specific sequence to bleeding the brakes on linked brakes.
If you need a manual, check the manual section.

In that case I'd say you've got a heap of air in the system or the rear master is cactus. In any case you'll have to start with a bleed to be able to see what's going on. Good idea to change your fluid anyway, if you don't know the last time it was changed, as brake fluid takes up moisture from the air and looses it's properties. That's not your main prob though since you've got no pressure at all. Good luck mate.

Any idea how long it's been sitting?
Personally I'd just get the calliper off and see if the pistons move at all when you press the brake pedal. If you've got nothing you may need to at least give them a squirt of WD40 and try pushing the pistons back in to free them up. Even if you had pure water in the system they should still move a bit.
If they're really stuck then a new (second hand) calliper is probably going to be your answer.
As everyone else says, you really need to study the linked brake system to understand it. It's a whole appendix on its own but don't be disheartened, it'll make excellent bed time reading..... he he!
Good luck.

An expert hack, absolutely! Now where's my hammer!!

The textbook method for bleeding the cbs system is as follows

The front brakes on a cbs system are just like any other non cbs bike - direct link between master cylinder and calipers.

Ensure the FRONT master cylinder is full and does NOT run dry :

Bleed the RIGHT OUTER nipple.

Then bleed the LEFT OUTER nipple.


Ensure the REAR master cylinder is full and does NOT run dry :

Bleed the FRONT RIGHT CENTRE nipple. (this will take a while as this is the main line!!)

Bleed the FRONT LEFT CENTRE nipple.

Bleed the BACK CENTRE nipple

Bleed the BACK OUTER nipple

DO NOT let either master cylinder run dry or your back to square one.

A vaccum bleeder is the best system

Speed Bleeders come a close second

You - a mate and a six pack is the most enjoyable way - haha