[swoop]

ok all you razor sharp gearheads! bear with me. I was wondering if we never use our rear brakes, do we need to change the brake oil regularly or at all? I know this may be a stupid question but from a point of view not from a gear head its makes perfect sense, and being I don't know what color new brake oil is or should look like. hence the question. the current color is like a dark apple cider color and the brake arm has travel and brake light comes just fine



thanks

 

[[email protected]]

I don't ever use the rear brake and there are several reports out there that using the front brake alone compared to the front and rear brake does not stop you a tremendous amount faster. Using the rear brake there is far more of a chance to get into trouble than there is to prevent an accident from stopping. When I had my speed triple I was trying to learn how to use the rear brake and trail brake. I used a little too much rear brake too deep into the turn and got into trouble. I didn't go down or get hurt, but I did hit the guard rail and scrape things up (luckily I was wearing full gear and good boots).

But, to answer your question...I don't think you should need to use the rear brake very often (if at all), therefore changing the fluid and pads is unlikely.

Hope this helps. I'm sure there are riders out there that use it, but I've never found the need. Even at the track.

 

[SlowMo]

Personally, I rarely use the rear brake - at times it is the only thing you will have available -- for example, if you ever run off track/road and onto grass. You want to stay as far away from the front brakes as you can.

At the track it's sometimes handy to help back it into a corner so to speak.

For these reasons alone I keep the brake fluid in good condition and change it every year on both track and street bikes.

 

[swoop]

ok see that's my idea also, I never use it and I don't track my bike. I know I did a full replacement of pads front and back not to long ago and was concerned about the color of the oil and if it would lose it property's over time even if it wasn't used. cool thaks

 

[newjerseyduke]

Brake fluid essentially runs on 2 clocks. First is usage. The more it's used and heats up and cools down the more it will break down over time. Secondly is just time itself. Brake fluid is hygroscopic meaning it draws moisture from the air and slowly goes bad by itself regardless of if it's actually being used. Bad brake fluid can rot brake lines and gum up calipers. So use it or don't. But do keep it in good shape.

 

[steve59]

The SDR has linked brakes so even if like me you never touch the pedal there will be weAR.

 

[[email protected]]

Personally, I rarely use the rear brake - at times it is the only thing you will have available -- for example, if you ever run off track/road and onto grass. You want to stay as far away from the front brakes as you can.

At the track it's sometimes handy to help back it into a corner so to speak.

For these reasons alone I keep the brake fluid in good condition and change it every year on both track and street bikes.

Great point about going off the track and into the grass and avoiding the front brake. That hasn't happened to me yet, but I'm sure I'll be trying to avoid ****ting in my shorts rather than braking at that point! lol:wink2:

 

[newjerseyduke]

The SDR has linked brakes so even if like me you never touch the pedal there will be weAR.

you sure about that. not 14+.

 

[steve59]

Pretty sure I read it although it may have read linked abs, safer not to quote me on anything.

 

[SlowMo]

Great point about going off the track and into the grass and avoiding the front brake. That hasn't happened to me yet, but I'm sure I'll be trying to avoid ****ting in my shorts rather than braking at that point! lol:wink2:

First time I went off track I had the front brake applied for a split second after leaving the pavement. Front locked up and promptly crashed, broke my collarbone and trashed the motor on my old sv1000. Ran off a few times after that - believe me, I learned my lesson - NO FRONT BRAKE! As for filling the old trousers, you have to maintain a sense of calm and give very easy, measured inputs due to the lack of traction.

The other reason I like to have the rear brake ready to go is just in case there's a front brake failure somehow or another. Blown master cylinder and suddenly no brakes whatsoever.

Also, it's a good idea to sit on your rear brake whenever you're at a stop light. I'm guessing you don't have the front brake applied at traffic lights, so you don't have any indication of being stopped to anyone that's coming up behind you (especially nowadays, with all the people texting and generally not paying attention).

 

[jtsharps]

Brake fluid essentially runs on 2 clocks. First is usage. The more it's used and heats up and cools down the more it will break down over time. Secondly is just time itself. Brake fluid is hygroscopic meaning it draws moisture from the air and slowly goes bad by itself regardless of if it's actually being used. Bad brake fluid can rot brake lines and gum up calipers. So use it or don't. But do keep it in good shape.

My point of view is the same as this one. I personally use my rear brake every time I use the brakes. It's just how I've always done it and it works the best for me. I would say even if you don't use them, you'll still want to keep them in good, working order. If the same fluid stays in there for years and gums everything up, you will be replacing more in the end. Or if like stated earlier, suddenly your front brakes go out and and you crank on the rear brakes...you won't like the outcome. Pads can also get glazed and bad if they're not used.

The fluid should be more light tan, almost like a lighter beer color. It gets darker over time with use, age, and heat from the motor. This means it's time to change it for me.

 

[swoop]

well at stop lights I do stand on the back brake for that reason alone, just not used for stoping

 

[rrjames81]

I wouldn't worry about them to much but as others have said brake fluid is hydroscopic and will go bad over time. I try to bleed mine though once a year. Its cheap insurance, brake fluid is cheap in the scheme of things and it doesn't take long to do the job right.

 

[cors187]

Informative thread.

 

[Jericho]

I would replace it. The fluid will absorb water and will have a corrosive affect on the caliper. Its cheap insurance, especially if you ever have to use the brake and its just a little maintenance.

 

[Frostback]

I too have followed the advice but for the life of me, I can't figure out how any significant amount of water can get into my brake lines if the hydraulic fluid cannot get out of them. I go 5-7 years at a pop before replacing the fluid and though there was some crud, I saw no real change in the quality of the fluid or the feel of the levers. I don't use my brakes much on the road bike however. It is mostly hours of droning along. I only use the rear in tight conditions or low traction slick environments.

Lee

 

[Barnapkin]

The rear brake does play a smaller role in outright braking; especially in a straight line. Where the rear brake comes into play is settling the suspension a split second before applying the front brakes. After all, if rear brakes were useless, MotoGp riders would not have them on their bikes. Learn to just rest the rear foot on the rear brake lever before you apply the front. I adjust the rear so I cannot lock up the rear. Try it out in a parking lot. Anyway, people don't practice braking as much as they exercise the right wrist.

 

[SlowMo]

Learn to just rest the rear foot on the rear brake lever before you apply the front. I adjust the rear so I cannot lock up the rear. Try it out in a parking lot. Anyway, people don't practice braking as much as they exercise the right wrist.

Rear brake is also useful for anti-wheelie application on bikes like the RC8r - or any analogue bikes without launch or wheelie control. Otherwise, I pretty much never use it.

 

[Edwin]

I use my rear brake all the time, it helps to get the bike to lean in when I'm coming in too hot.

About the water in brake lines...

The water vapor comes in from the reservoir cap which has to have a breather; as the pads wear out, the oil level drops and air comes in to fill the space. (It it was air tight, it would vacuum lock, sucking the caliper away from the rotor. Even a fraction of a millimeter of excess play between of and rotor would give you a soft spongy feel, hence the breather is necessary.) If you look closely at the cap, you will see it has a double wall with a floating component to prevent oil spilling out. There's very little oil in a brake system, it thus also require only a tiny bit of moisture-laden air to condense. That drop of water will cause pitting in the master and slave cylinders then they can't hold pressure, and there's no rebuilding pitted sleeves. Therefore maintenance calls for replacing the fluid.

Lastly, the color change is from the heat of the brakes, not the engine. Brake fluid gets very hot in the caliper, 500+ degrees is common for spirited street use (bike or car). Dirty oil loose it's ability to absorb heat; when it overheats, bubbles form from boiling, then next time you grab a handful of footful of brake, there are bubbles of air which compresses taking up all your pedal travel. If you're lucky you'll have time to pump the brakes else you crash.

Sent from my SM-N981U1 using Tapatalk

 

[zgrothus]

Lots of good info in here!

I don't use my rear brakes very often, but being that brake fluid is hydroscopic and can gum up the internals, I flush the rear once a year. I'll flush my front lines several times a year. This is what good ol dad taught me, plus it only takes a few bucks and a few minutes for some peace of mind.