I have rebuilt nearly everything on my my bike.
The issue I'm having is this;
The back brake caliper is dragging on the rotor.
I took the rear caliper was disassembled and that seem fine.
No rust.
I reinstalled the same seals back because they seemed fine
The adjuster is all the way in
could the rear master cylinder be bad????
Could the pressure applied to the caliper not be releasing once the brake is released???
HELP :dash1:
Yes, certainly.
Within the master is a drainback hole that allows pressure to equalize when the piston is out (resting state). It mostly makes it so that as the pads wear you don't have to push the lever farther until you get brakes, they should feel the same all the way through.
Easy enough for a bit of crap to get in the way there and cause problems.
The rear caliper is also in a good position to get covered with road crap though, and bind up. If the mount is bent, if there's crap someplace on the bolts, etc, it's also possible that it can be installed slightly cockeyed too, which will make it drag a bit.
If you've taken the caliper down and gotten everything nice and clean and it still does it (I'm assuming you had to bleed the system when you put it back on), then sure, may as well pull the master apart and see what's going on there. Possibly a good cleaning will suffice.
The caliper itself is dragging.......or one of the pads?
Harvy
wow....
thanks
Harvy
the pads both seem to be dragging
i have R1 front calipers
everything new there
Everything was good when I first did my fzr1000 rear wheel upgrade
what holds the rear master cylinder together a cir clip?
As Andy replied mate.......if it was just the one pad, I would have suggested a stuck piston, but as its both sides, Andy's suggesting of a bit of crap in the master fluid return port is likely, or maybe the master piston is not returning/stuck somehow?
I've not pulled one apart on the FJ.....looking at the parts diag, its an internal C-clip.
Harvy
i'll look at the parts diagram.
That section is missing in my repair manual
Quote from: andyb on June 15, 2010, 08:32:52 PM
Yes, certainly.
Within the master is a drainback hole that allows pressure to equalize when the piston is out (resting state). It mostly makes it so that as the pads wear you don't have to push the lever farther until you get brakes, they should feel the same all the way through.
Easy enough for a bit of crap to get in the way there and cause problems.
The rear caliper is also in a good position to get covered with road crap though, and bind up. If the mount is bent, if there's crap someplace on the bolts, etc, it's also possible that it can be installed slightly cockeyed too, which will make it drag a bit.
If you've taken the caliper down and gotten everything nice and clean and it still does it (I'm assuming you had to bleed the system when you put it back on), then sure, may as well pull the master apart and see what's going on there. Possibly a good cleaning will suffice.
Andy...THANK you
Quote from: ccsct203 on June 15, 2010, 08:46:18 PM
i'll look at the parts diagram.
That section is missing in my repair manual
Check this site........this for '91 master, but I believe they are all the same.
http://www.boats.net/parts/search/Yamaha/Motorcycle/1991/FJ1200B/REAR%20MASTER%20CYLINDER/parts.html (http://www.boats.net/parts/search/Yamaha/Motorcycle/1991/FJ1200B/REAR%20MASTER%20CYLINDER/parts.html)
I like this site for cross referencing.
If you click on the part number in the listing, A new window will show you every Yamaha bike this part was used OEM.
Harvy
Ok, THAT is a cool fische.. I like that...
I'll disassemble it tonight.
It's dragging way to much even to ride a short distance.... :dash1:
I'll try cleaning it first and look at the cylinder bore.
at the price of $72 for a rebuild kit a used ebay unit looks much better
Thanks Harvey...good find...awesome site. I am always checking to see what else certain parts are used on. And I can even search for parts for the fishing machine now... :dance2:
(http://i124.photobucket.com/albums/p21/jvb_ca/NautiMe/Nauti_me1_cr.jpg)
Cheers...Jake
Quote from: Harvy on June 15, 2010, 10:13:38 PM
Check this site........this for '91 master, but I believe they are all the same.
http://www.boats.net/parts/search/Yamaha/Motorcycle/1991/FJ1200B/REAR%20MASTER%20CYLINDER/parts.html (http://www.boats.net/parts/search/Yamaha/Motorcycle/1991/FJ1200B/REAR%20MASTER%20CYLINDER/parts.html)
I like this site for cross referencing.
If you click on the part number in the listing, A new window will show you every Yamaha bike this part was used OEM.
Harvy
The best way to determine if it is a master cylinder or caliper problem is by opening the bleeder at the caliper and seeing if there is a small squirt of pressure.
If the master cylinder return port is clogged or partially blocked then the system will maintain the pressure. By cracking the bleeder screw at the caliper you should see a small squirt of fluid. You can check this several times if needed. Close the bleeder, pump the brakes several times and release. Now go back and crack the bleeder to see if you release the pressure.
If there is no pressure then the master cylinder is fine and the caliper is the problem. You might also check the rubber hose and make sure it has not de-laminated internally and has created a flap that is blocking flow.
Sorry, I don't have a source for that rebuild kit...
Good luck, Randy - RPM
i'll try it tonight.
Thanks again
Maybe some build-up internally, small bore to clean so I'll have to do the best I can.
Maybe If I just buy one on Ebay....
Quote from: ccsct203 on June 15, 2010, 08:26:19 PM
I have rebuilt nearly everything on my my bike.
The issue I'm having is this;
The back brake caliper is dragging on the rotor.
I took the rear caliper was disassembled and that seem fine.
No rust.
I reinstalled the same seals back because they seemed fine
The adjuster is all the way in
could the rear master cylinder be bad????
Could the pressure applied to the caliper not be releasing once the brake is released???
HELP :dash1:
Here's my experience. Dirt on the piston tends to damage the dust seal (the outer seal). These get torn & jam the piston. You could replace the dust seal or simply remove it. This works ok and the piston isn't adversely affected by dirt or corrosion.
Stuart
G'day ccsct203, I'm having a similar problem with my '85 1100 at the moment. My problem is only occurring occasionally, so it's fairly difficult to find the problem. You can apply the brakes lots of times when it's parked in the garage on it's centre stand and they seem fine, but take it for a ride and some times they stay on but most of the time, they're fine.
So far I've replaced the disc and pads,(which were worn) thinking that they were allowing the piston to travel too far and not return, also drained and renewed brake fluid and cleaned master cylinder. So far, after a couple of rides it seems fine, fingers crossed I've fixed it. Pete.
ok
I took the rear master cylinder apart and blew out the small .015 diameter hole
put it all back together and it seems better.
I'm wondering ...as I look at the pistons.. one is out further then the other.
This is due to my 18" wheel upgrade.
Could on piston out to far be the issue?
I'm buying a used fj1200 caliper and I'll rebuild it with Randy's kit.
let me know what you think
it is better but not perfect.
Maybe one new pad and one older pad to reduce the piston out too far?
Quote from: ccsct203 on June 16, 2010, 09:31:21 PM
I'm wondering ...as I look at the pistons.. one is out further then the other.
This is due to my 18" wheel upgrade.
Could on piston out to far be the issue?
Maybe one new pad and one older pad to reduce the piston out too far?
Ahha........ that tell me one of 2 things.......either you have 2 unmated pads in there.....or more likely, the calliper is not sitting centrally over the rotor.
Looking from the back of the bike at the calliper sitting over the rotor...... there is a line in the middle of the calliper housing......it should be sitting perfectly over the centre line of the rotor.
If not, I would suggest a bit of shimming on one side of the calliper mounting arm, and/or removal of material on the other side to bring it into alignment.
Then shout yourself a new set of pads.
I had a similar issue when I did the 18" Genesis rear wheel..... followed the instructions to the mm on all machining, but the caliper was a mm or 2 too far inboard........a washer between the spacer and the caliper mounting arm solved my problem.
Hope we have finally nailed it.
Harvy
Quote from: Harvy on June 16, 2010, 09:48:14 PM
\
...or more likely, the calliper is not sitting centrally over the rotor.
Which is exactly where we were with this same caliper in the other thread on May 26.
Randy T
Indy
The rotor is sitting far centered.
there is more then a few mm misalignment.
the inboard piston is extended further then the outboard.
I can't add washers between the caliper and the support bracket, this would worsen the problem.
so what you are telling me is that both pistons should be extended the same distance?
I have two options... machine the caliper mounting tabs where the bolts attach or shim behind the inboard brake pad to "fool" the piston and force the piston back in the caliper the same distance as the outboard piston.
Would both of these options work?
THanks guys
The way a brake caliper works, it shouldn't matter if it is offset slightly to one side..... once you pump the lever a few times, the pads will be pushed out to the rotor, and if the seals are good, they'll retract the piston a few thousandths. There's got to be something preventing this... either crud on the piston, or something preventing fluid from returning to the MC/reservoir.
Quote from: ccsct203 on June 16, 2010, 10:04:40 PM
I can't add washers between the caliper and the support bracket, this would worsen the problem.
so what you are telling me is that both pistons should be extended the same distance?
I have two options... machine the caliper mounting tabs where the bolts attach or shim behind the inboard brake pad to "fool" the piston and force the piston back in the caliper the same distance as the outboard piston.
Would both of these options work?
THanks guys
Not between the calliper and the support bracket.......down at the axle is where you add the washer if necessary - between the bracket and the spacer will move the bracket/calliper assembly out......... and machining of the bracket where the axle passes thru it on the inside, will move the entire assembly inwards.
I would not be shimming anything in the calliper myself, just get it sitting centrally over the rotor and all will be good.
Harvy
Quote from: RichBaker on June 16, 2010, 10:11:31 PM
The way a brake caliper works, it shouldn't matter if it is offset slightly to one side..... once you pump the lever a few times, the pads will be pushed out to the rotor, and if the seals are good, they'll retract the piston a few thousandths. There's got to be something preventing this... either crud on the piston, or something preventing fluid from returning to the MC/reservoir.
Slightly being the operative word........ it only needs to be slightly more than slightly and the rotor will be rubbing on one side or other of the calliper.
Harvy
the offset is more then slight
I would need to shim out the caliper bracket
I don't know if there is enough room to add any shims in there
I'll check the difference with calipers tonight and then I have a dimension of what I'm dealing with
I'll try to take a pic also
Very old post but similar problem:
Yesterday I cleaned whole rear brake system (I have Fazer 1000 calliper and FJ1200 ABS MC):
- calliper (I took out pistons and I cleaned all inside)
- master cylinder was disassembled and cleaned. All parts inside in really good condition.
Today after 5 minutes ride I started feel strong drag on rear brake. After slow return home rear disc was really hot. When I unbolted calliper It was impossible to push back pistons - but it was easy when I unscrewed bleeding screw. Also when I push brake pedal it will pump out brake fluid as it should.
So guilty can be brake line or MC. But I am not sure which one is guilty that it works as one way system....
There is a relief port in the m/c that's clogged. This port releases line pressure when the piston retracts.
those relief port is microscopic. How You think: drill it to 1mm size will be good idea???
No...I would not drill anything Karol.
Just another disassembly and cleaning. This port resides in the piston bore and connects between the pressure side and intake side of the circuit.
Pay attention to the remote reservoir and the connecting hose. Any crud in there can (and will) settle down into your m/c.
This is also common on the handle bar mounted m/c's (clutch and front brake) The relief port is located under a plate at the bottom of the reservoir. For through cleaning you have to remove these plates and get the accumulated crud off the bottom. With the plates out you can see these relief ports working. When you squeeze and release the levers, a little fountain of brake fluid will squirt up out of these relief ports as the line pressure is relaxed.
The plates are there to prevent this fountain of fluid from causing you headache and damage.
When I converted over to non hygroscopic DOT 5 I removed these plates. I no longer worry about brake fluid spills.
Hope this helps.
Let me tell you a story....
Back in the days of the Red Dog Saloon, I owned an auto repair shop. One day a truly ancient Mercedes-Benz rolled into the shop with a weird problem. Seems if you applied the brakes (while driving) the car would dart hard to the right. If I muscled the car straight with the steering wheel and kept pushing on the brake pedal (as in coming to a stop) the car would eventually stop pulling to one side. But then when I released the brake pedal (car still moving) the car would now dart to the left. Much head-scratching ensued...
Eventually we discovered that the left brake hose looked perfectly fine on the outside, but had swelled almost completely shut on the inside. The right brake would get pressure just fine and the left brake would not, causing the hard swerve. But eventually, with continued pushing on the brake pedal, the master cylinder would develop enough pressure to slowly bleed past the restriction in the hose, and now the left brake would work. But when I let off the brake pedal... here's the important part... the swollen hose would keep pressure in the left brake, causing the car to swerve the other direction. In other words, the hose was acting as a one-way check valve.
We replaced all of the brake hoses, bled the brakes, and the customer drove away happy.
It is entirely possible that you have a bad hose, and it is not allowing the pressure to bleed off.
Bill
Quote from: CutterBill on March 08, 2016, 10:33:26 PM
Let me tell you a story....
Back in the days of the Red Dog Saloon, I owned an auto repair shop. One day a truly ancient Mercedes-Benz rolled into the shop with a weird problem. Seems if you applied the brakes (while driving) the car would dart hard to the right. If I muscled the car straight with the steering wheel and kept pushing on the brake pedal (as in coming to a stop) the car would eventually stop pulling to one side. But then when I released the brake pedal (car still moving) the car would now dart to the left. Much head-scratching ensued...
Eventually we discovered that the left brake hose looked perfectly fine on the outside, but had swelled almost completely shut on the inside. The right brake would get pressure just fine and the left brake would not, causing the hard swerve. But eventually, with continued pushing on the brake pedal, the master cylinder would develop enough pressure to slowly bleed past the restriction in the hose, and now the left brake would work. But when I let off the brake pedal... here's the important part... the swollen hose would keep pressure in the left brake, causing the car to swerve the other direction. In other words, the hose was acting as a one-way check valve.
We replaced all of the brake hoses, bled the brakes, and the customer drove away happy.
It is entirely possible that you have a bad hose, and it is not allowing the pressure to bleed off.
Bill
Had the same problem in a 56 Nomad that was "restored". I replaced all the lines and no problem after that. What was an eye opener is the large diameter looking brake hose when cut open the feed hole was around only 1/16 inch in diameter or less. Recently I observed a neighbor doing his own brakes and had a heavy caliper off the rotor and dangling down by the hose. I cringed.
George
I cleaned up today whole system: and again was hard to press back pads - compare to force needed without calliper connected to the system and compare to force needed on front callipers
Then I realised that since beginning I have doubts about rear disc temperature..... Even after change to Fazer 1000 brake system and later braided line.
So I took out master cylinder and I tried clean relief port with thinnest wire at home: I tried split cable, fishing line...... Actually I did not try human hair..... :crazy: I could not press inside anything....
So I decided: drilling. I used 1 mm drill. After I assembled all together finally I can push back pads without any problem. Braking is extremely good and rear disc is finally cold when not in use.....
I will give it few more miles tomorrow. And probably I will buy spare MC from non ABS FJ....
Few observations after today's ride:
- much easier to push bike back or forward while sitting on it
- different feeling when I use rear brake. Now I can much more precise dosage braking power.
- Brake disc is cold when not in use. It is getting very hot even after short braking, I checked on internet and it seems that it is normal in Fazer.
Minus: Voice in my head whispering: You idiot - You tampered with brakes.....
Quote from: movenon on March 08, 2016, 10:50:55 PM
.......... Recently I observed a neighbor doing his own brakes and had a heavy caliper off the rotor and dangling down by the hose. I cringed.
George
George, this is one of our very own members bikes recently with calipers hanging by the hoses.
(https://c2.staticflickr.com/2/1482/25775109995_e8eff99241_c.jpg)
While probably not a good habit, those lines have to withstand approx 350 lbs minimum tensile strength to pass the required standards and most manufacturers are going to exceed that by a considerable margin. Brake hoses are a lot tougher than most folks think.
As I said, I wouldn't recommend it but it's probably not doing any harm either.
Noel
Quote from: MOTOMYSZOR on March 09, 2016, 12:29:08 PM
I cleaned up today whole system: and again was hard to press back pads - compare to force needed without calliper connected to the system and compare to force needed on front callipers
Then I realised that since beginning I have doubts about rear disc temperature..... Even after change to Fazer 1000 brake system and later braided line.
So I took out master cylinder and I tried clean relief port with thinnest wire at home: I tried split cable, fishing line...... Actually I did not try human hair..... :crazy: I could not press inside anything....
So I decided: drilling. I used 1 mm drill. After I assembled all together finally I can push back pads without any problem. Braking is extremely good and rear disc is finally cold when not in use.....
I will give it few more miles tomorrow. And probably I will buy spare MC from non ABS FJ....
To clear that little hole all you need is a piece of #1 E guitar string. Small enough diameter to get in the hole and stiff enough to shift the crud.