Yamaha Starbike Forum banner

1 - 20 of 26 Posts

·
Registered
Joined
·
270 Posts
Discussion Starter #1
Never bled brakes on a bike before. I did have to compress the caliper a bit and I did not notice any fluid from the res.

Should I still bleed them? I can get my hands on a vacuum bleeder. I read something about bleeding the master as well as the caliper. Is this true that you have to do both?

Just wanna make sure I do it right.
 

·
Registered
Joined
·
1,315 Posts
open the reservoir if the fluid is dark change it, you can put a hose over the bleeder screw open it and put the end in a recovery vessel then pour new fluid in the reservoir ( don't let it go dry ) until it runs clear out of the hose. sometime it will gravity feed and sometime you have to squeeze the lever to get it going. on mine i sucked the fluid up with a baster so i could clean the reservoir sight glass. the reservoir was really dirty also. don't fill it above the sight glass or you'll have a mess when you install the cover. brake fluid is an oxidizer so wash it off quickly if it gets on anything. brake fluid dissolves in water so have some nearby for a washdown when you finish.
 

·
Registered
Joined
·
1,090 Posts
You don't HAVE to change the fluid but it probably wouldn't hurt. FWIW, unless you open a bleeder screw and allow air into the system, changing pads does not require bleeding the system.
 

·
Registered
Joined
·
2,181 Posts
It depends on the last time you changed it. Yamaha recommends a complete brake fluid change every 2 years on most cruisers. If it's been longer thn that.....it's time to drain, fill and bleed with new fluid.:smile: ...especially if you are in a climate with humidity.

I try to do it every other year, since brake fluid absorbs moisture, it can lead to pitting.....fortunately I live in AZ with very little moisture in the air, so I could probably go longer. I usually just end up doing something on the bike that requires bleeding...so I just dump all the fluid and add new.
 

·
Registered
Joined
·
845 Posts
Should I still bleed them? I can get my hands on a vacuum bleeder. I read something about bleeding the master as well as the caliper. Is this true that you have to do both?

Just wanna make sure I do it right.
Yes, changing the brake fluid is required maintenance every two years by Yamaha, in fact almost every motorcycle brand that I know of, including my new bike.

I was on a vstar 1300 (2 up) in the mountains of NC and had rear brake failure on a mountain road due to not changing the fluid, it wasnt a lot of fun coming down the mountain with just front brakes, that was when I learned it was required maintenance. Brake Fluid attracts moisture and as it builds up, water, water boils when hot, creates vapor lock and then no brakes, brakes do start working again once it cools down which I learned at the bottom of the mountain. Also moisture will take a toll on your calipers/master cylinder over time.

I'll NEVER forget that day, I tried my best to keep my cool, keep control of the bike and keep the bike on the road, more so for the sake of my wife/passenger on the back of the bike. I honestly could not be sure of what the outcome was going to be, if we would make it to the bottom of the mountain, more so if the front brakes went out after losing the rear. You can bet I will always do the 2 year required brake fluid change.
 

·
Registered
Joined
·
270 Posts
Discussion Starter #6
I pulled out the old fluid, it was pretty dark and I used a pump at the do caliper to pull the air out. Once its together im gonna do another bleed for the hell of it.
 

·
Registered
Joined
·
845 Posts
I pulled out the old fluid, it was pretty dark and I used a pump at the do caliper to pull the air out. Once its together im gonna do another bleed for the hell of it.
Yes, its amazing isnt it? you dont realize how dark it gets, after replacing it (depending on brand I guess) mine was so clear you couldnt see the fluid in the window, had to look for the bubble at the top of the glass.

I always follow the maintenance manual however for some reason, Yamaha (at least on my vstar) had the required 2 year brake fluid change in the "Notes" section at the very tail end of the whole maintenance schedule and was something I never bothered to read.
 

·
Registered
Joined
·
1,315 Posts
I pulled out the old fluid, it was pretty dark and I used a pump at the do caliper to pull the air out. Once its together im gonna do another bleed for the hell of it.
brake fluid is very corrosive i think it gets contaminated from stuff that it has dissolved like the reservoir and hose. it would make a great paint stripper although i'v never seen it used for that. the weird thing about brake fluid is that it dissolves in water so its definitely not oil based like regular hydraulic oils are
 

·
Registered
Joined
·
270 Posts
Discussion Starter #9
Side note..went for a ride Sunday. Apparently I did not do a good job of cleaning and lubing the caliper. I noticed the wheel was semi hard to rotate. Also getting a small squealing on higher speeds. Once I unbolted the caliper the wheel spun nice and free.
 

·
Registered
Joined
·
270 Posts
Discussion Starter #11
Quick question for everyone....do you guys grease your front brake sliders and with what grease?
 

·
Registered
Joined
·
1,315 Posts
Side note..went for a ride Sunday. Apparently I did not do a good job of cleaning and lubing the caliper. I noticed the wheel was semi hard to rotate. Also getting a small squealing on higher speeds. Once I unbolted the caliper the wheel spun nice and free.
if cracking the bleeder releases the wheel it's the line not the caliper. sometimes the rubber breaks down in the line easier to try that first than to pull stuff apart for inspection. pull the brake hard to set the drag then crack the bleeder. i cut a piece of wood to fit under the right frame rail then push bike hard onto the kickstand and set the board to keep the wheel off the ground. i wanted a quick and easy way to check wheel bearings because it's hard to tell tire noise from bearing noise when riding.
 

·
Administrator
Joined
·
13,283 Posts
Quick question for everyone....do you guys grease your front brake sliders and with what grease?
i haven't, but it's recommended to use lithium-based soap or brake grease to grease the pistons in the calipers, the retaining pin, and where the pad seats into the caliper
 

·
Registered
Joined
·
270 Posts
Discussion Starter #14
i haven't, but it's recommended to use lithium-based soap or brake grease to grease the pistons in the calipers, the retaining pin, and where the pad seats into the caliper
I got some pretty good stuff from Napa im gonna try out tomorrow. Siliglyde I think its called.
 

·
Registered
Joined
·
270 Posts
Discussion Starter #15
So that didn't do it. I cleaned and greased the sliders. Bolted it back together and applied the brake. After a few pulls the front tire got tight again to rotate. I'm getting confused and mad now lol.


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
1,090 Posts
It can only be one of two things in my opinion...either the caliper itself is binding up somewhere or the pistons are not releasing properly. When you install the caliper but before you apply the brakes you should be able to easily move the caliper back and forth slightly on the slides. I would consider removing and reinstalling everything again just to be sure everything is correct and aligned properly. Not sure if you are working on a 650 or 1100 but if its an 1100 did you swap sides with any of the parts? just a thought.
If that doesn't I would look into the caliper. As someone mentioned earlier...apply brakes until the caliper is stuck, then crack the bleeder. If pressurized fluid comes out and the caliper releases you need to replace the hose. Hoses deteriorate from the inside and start to restrict the flow of fluid. This problem usually shows itself over time, not in an instant like you are experiencing but it could be the flexing of the hose while removing the caliper that created the issue. If the caliper doesn't release the piston is sticking within the caliper body. Technically I suppose something could be wrong in the master cylinder that is preventing it from releasing properly but you didn't have this problem before and to my knowledge you haven't done anything to the MC so I wouldn't think that was a likely probability. Did you rebuild the calipers or just replace pads?
 

·
Registered
Joined
·
270 Posts
Discussion Starter #17
It can only be one of two things in my opinion...either the caliper itself is binding up somewhere or the pistons are not releasing properly. When you install the caliper but before you apply the brakes you should be able to easily move the caliper back and forth slightly on the slides. I would consider removing and reinstalling everything again just to be sure everything is correct and aligned properly. Not sure if you are working on a 650 or 1100 but if its an 1100 did you swap sides with any of the parts? just a thought.
If that doesn't I would look into the caliper. As someone mentioned earlier...apply brakes until the caliper is stuck, then crack the bleeder. If pressurized fluid comes out and the caliper releases you need to replace the hose. Hoses deteriorate from the inside and start to restrict the flow of fluid. This problem usually shows itself over time, not in an instant like you are experiencing but it could be the flexing of the hose while removing the caliper that created the issue. If the caliper doesn't release the piston is sticking within the caliper body. Technically I suppose something could be wrong in the master cylinder that is preventing it from releasing properly but you didn't have this problem before and to my knowledge you haven't done anything to the MC so I wouldn't think that was a likely probability. Did you rebuild the calipers or just replace pads?
It is a 650 fyi. I cracked the bleeder after the brakes felt like they were hanging and fluid did come out however it did not make the wheel move any easier. I never had this issue before like you stated. I never rebuilt the caliper but I did have to use a C Clamp to compress the pistons in and I thought ive read in other places it shouldn't be that had to compress, so maybe the calipers needs to be replaced or rebuilt? The one other thing I read was if you overfill the Master this might happen as well. I think that the brake master sight glass was showing fluid on the higher side.

If not maybe now would be a good time to learn how to rebuild calipers....
 

·
Registered
Joined
·
1,090 Posts
I have more knowledge with cars than bikes but I have always used a c-clamp to compress the calipers. There is an o ring on the piston that seals it and also works to pull it back once the pressure is released. If you loosen the bleeder and the caliper does not release then the caliper is the problem. With the bleeder open there is no pressure inside the caliper therefore the piston apparently is not sliding freely as it should. Not sure if these can be rebuilt but if it's like many cars today is almost just as well to replace as take the time to rebuild. I know there are others here with more experience than me but based on what you say I would be changing the caliper. The old fluid could have caused corrosion inside the caliper and on the cylinder walls. It may have been working fine previously but with the pads worn down the piston was extended out further in the cylinder than with new pads. The piston o ring could very well be sitting on a tiny spec of corrosion now that keeps it from releasing completely. Make sense?
 

·
Registered
Joined
·
1,315 Posts
how much binding are we talking because mine always had a slight drag very slight but there none the less, on very rare occasions i had to file shoes that fit to tight on the slides but in your case it's probably one of the pistons hanging which installing new seals should fix look at the chrome on the pistons if it's not perfect they sell kits with seals & pistons about 35.00 seals alone 25.00
 

·
Registered
Joined
·
270 Posts
Discussion Starter #20
how much binding are we talking because mine always had a slight drag very slight but there none the less

Enough for me to notice when I'm trying to move the bike around on foot. I'll try to take a video of me attempting to freewheel it.


Sent from my iPhone using Tapatalk
 
1 - 20 of 26 Posts
Top