brake problems

[Sideburns]

Air works for me.
I used to do it with a bicycle pump. (I AM from the Netherlands)
You don't need much pressure. My compressor is adjustable.

There is always one that comes out. Take out the O-rings and put it back. Hold that one and the next one will come out. etc. etc.
Main concern is that you take your time and be gentle. You can damage them if they pop out to fast and hit something hard, the wrong way.

Apart from some some handywork (modified bicycle pump with hose that fits the calliper/hose+Syringe   for bleeding) you don't need more than basic tools.

[Sideburns]

It's pretty easy if you have airpressure to pop out the pistons.

I would always try the old o-rings first. I've found that cleaning the calliper solves the problem, most of the time
I also found that OEM o-ring are a lot better than imitation ones.

This is roughly how I do it:

I use an old brakeline as an airhose with the nozzle of the airpistol stuck in the hose.
Scotchbrite and brakefluid are perfect for cleaning the pistons.

For the calliper itself I use Lamp oil (parafin oil) I've yet to find a better multipurpose cleaner than lamp oil.
Doesn't cost a dime, doesn't hurt paintwork, dissolves oil and baked-in old grease like the best.
Also works great on brakedust.  Hold one pistons in place with a good tie rip and pop out the other piston.
Note: Take it easy. you can damage the psiton if it pops out to fast/hard  A piece of plywood over the piston you arent popping out, clamped to the workbench on either side of the caliper works well.
Blow out all excess brakefluid.
remove both o-rings and put the piston back in the calliper
tie rip around that piston and pop out the other piston.
remove both O-rings.

with airpressure, the other (the one you put back) should come out. If if doesn't, you can fill the first hole with a cloth to direct more pressure to the piston still in place.

thoroughly blow out the empty calliper.
With brakecleaner clean the caliper.

clean/Grease and reinstall the o-rings.
don't pull on old o-rings. you'll make them longer and they'll be a b*tch to reinstall
Be gently
Use a purpose grease.

clean the pistons with brakefluid and scotchbrite. Grease and reinstall.

For bleeding I use a simple piece of hose that fit's over the bleeding nipple and a large sering  Syringe, took me a few seconds to figure out what you meant.   
(total cost less than $2,-)

Takes me about 30 minutes  and 2 beers from removal of the bike to re-installment on the bike.
Forgive my English. It might be "crooked at times" I'm Dutch. I bet your Dutch is worse  

Not too bad 
Now you try some Dutch!

[RichBaker]

No thanks....  I took German in High School, but that was many, many years ago......   

[Carterc]

i ended up taking it all apart due to failure no matter what i did and found out that oil is not getting through my rear master cylinder assembly, at all. I'm really hoping i don't have to replace it because I don't have $230 to spend....... i figure ill take it apart when i get home and see where the blockage is. Is there anything i shouldn't use to clean it out with?

[craigo]

Kinda confused about the $230 to fix the rear brake. You can buy a replacement for under $50 right here:

http://cgi.ebay.com/ebaymotors/87-YAMAHA-FJ1200-FJ-1200-CALIPER-REAR-BRAKE-2-/330553025192?pt=Motorcycles_Parts_Accessories&hash=item4cf67ee2a8#ht_540wt_958

Looks to be a bolt on and bleed. And don't forget the crush washers.  

CraigO

[Carterc]

thats not what i need (so far), the master cylinder is not working properly, and the yamaha-motors site says the part is $230!

http://www.yamaha-motor.com/partviewer/default.aspx?ls=sport#/Yamaha/FJ1200S_-_1986/REAR_MASTER_CYLINDER/FJ1200S_%281986_MOTORCYCLE%29/REAR_MASTER_CYLINDER_%28FJ1200S_-_1986%29

#10 is what is not working properly

[rktmanfj]

thats not what i need (so far), the master cylinder is not working properly, and the yamaha-motors site says the part is $230!

http://www.yamaha-motor.com/partviewer/default.aspx?ls=sport#/Yamaha/FJ1200S_-_1986/REAR_MASTER_CYLINDER/FJ1200S_%281986_MOTORCYCLE%29/REAR_MASTER_CYLINDER_%28FJ1200S_-_1986%29

#10 is what is not working properly

Then order #11, and rebuild it...

[anson45]

SO CARTEC! 
Inquiring minds, with what appears to be the same problem, want to know how your rear brake situation was resolved.  I moved my '89 FJ around the garage with great difficulty friday and discovered my rear brake was almost totally locked up.
So how did yours work out?
Anson