K11 Owners Group

Scouse · Posted: Thu Apr 30, 2009 2:30 pm Post subject: Why change brake fluid?

I realize that all the info that I have read, say to change the brake fluid every year and sometimes twice as the fluid absorbs water, or something like that. But why?
I don't change the fluid on my car and have no problems. I have'nt changed the fluid on my bike either and find no problems. Can anyone explain? Bob

Jim · Posted: Thu Apr 30, 2009 3:33 pm Post subject: Re: Why change brake fluid?

Flying Duck · Posted: Thu Apr 30, 2009 4:08 pm Post subject:

Brakes are a hydraulic system. In order to work it's best, the fluid used should not compress under pressure. Brake fluid does absorb water. Water is more compressible than brake fluid so the more water that accumulates, the mushier your brakes will be. Water can also cause corrosion.

Ideally brakes should be bled annually so that you always have fresh pure brake fluid and optimal braking.

I don' tthink every other year is a bad idea however I live in Seattle where it rains a lot so the air stays fairly humid so I change mine annually.

You should also change the brake fluid in your car. The fluid in your car is OLD. As it has aged over time you probably have not noticed the slow degradation of your brakes. In addition, your car most likely has power assisted brakes which is another reason you might not notice old brake fluid. However, if you do change the brake fluid in your car you will notice the brakes working better.
_________________
93 LT (x2)
94 RS
86-97 K75F(K75/100/1100 Frankenbrick)
86 K75C w/paralever, hi perf cams,TURBO!
91 & 92 K75Ss
91 K1
86 custom K100
14 WR250R
IBA #17739 (SS1K, BBG, 50CC)
Buy parts HERE

Scouse · Posted: Thu Apr 30, 2009 4:21 pm Post subject: Brake fluid

Thanks guys that does make sense the system being smaller ans exposed more than a car. I will get to that this week. I have a 96K1100
Can I use any fluid or does it have to be DOT4 bOB

Jim · Posted: Thu Apr 30, 2009 5:31 pm Post subject: brake fluid

Bob - yes - DOT 4. Do not use the new stuff! Silicone or whatever it is...

(edited to correct technical content)
_________________
Jim
1997 K1100LTSE 94,000 - still has gremlins!
1995 R100RT Classic 16,650 crashed - repaired!
1992 K75RTP 46,000

"We shall not all die, but we shall all be changed."

Tim (Midland Section) · Posted: Thu Apr 30, 2009 6:32 pm Post subject: Re: brake fluid

Stoked Steve · Posted: Thu Apr 30, 2009 7:37 pm Post subject:

I agree with all the above, but Jim's comment caused me concern.

Flying Duck · Posted: Thu Apr 30, 2009 7:45 pm Post subject:

RAL88 · Posted: Thu Apr 30, 2009 7:48 pm Post subject:

+1 on the Valvoline
_________________
Rich

"If it ain't broke, take it apart and make it work better"
*************
'96' K1100LT-SE
'97' R850GS-R

Mystic Red · Posted: Thu Apr 30, 2009 8:32 pm Post subject:

Never seen syn dot 4. Does it attract water as bad as dyno?
_________________
Scott Hespelt, '94 K11LT
K11 OG #466

larryb22 · Posted: Fri May 01, 2009 7:23 am Post subject: Brake fluid

I don't quite agree that water compresses more than brake fluid. However brake fluid won't cause rust and corrosion like water does. I'd recommend changing brake fluid and coolant every two years. Another issue would be brake lines, old brake lines can break down too. Some brake lines out there are really old and should be changed as well.
Larry
_________________
2008 Yamaha XV250
S/W Michigan USA

RAL88 · Posted: Fri May 01, 2009 9:17 am Post subject:

Water does compress more than the brake fluid. It has to do with the chemical make up and the spaces between the bonds of the molecules, atoms, protons, electrons and neutrons that allow for the compression.
_________________
Rich

"If it ain't broke, take it apart and make it work better"
*************
'96' K1100LT-SE
'97' R850GS-R

LordGondor · Posted: Fri May 01, 2009 12:10 pm Post subject:

Found this on http://www.afcoracing.com/tech_pages/fluid.shtml

Guess I better change the fluid...

Water/moisture can be found in nearly all brake systems. Moisture enters the brake system in several ways. One of the more common ways is from using old or pre-opened fluid. Keep in mind, that brake fluid draws in moisture from the surrounding air. Tightly sealing brake fluid bottles and not storing them for long periods of time will help keep moisture out. When changing or bleeding brake fluid always replace master cylinder caps as soon as possible to prevent moisture from entering into the master cylinder. Condensation, (small moisture droplets) can form in lines and calipers. As caliper and line temperatures heat up and then cool repeatedly, condensation occurs, leaving behind an increase in moisture/water. Over time the moisture becomes trapped in the internal sections of calipers, lines, master cylinders, etc. When this water reaches 212º F the water turns to steam. Many times air in the brake system is a result of water that has turned to steam. The build up of steam will create air pressure in the system, sometimes to the point that enough pressure is created to push caliper pistons into the brake pad. This will create brake drag as the rotor and pads make contact and can also create more heat in the system. Diffusion is another way in that water/moisture may enter the system.

Diffusion occurs when over time moisture enters through rubber brake hoses. The use of hoses made from EPDM materials (Ethlene-Propylene-Diene-Materials) will reduce the amount of diffusion OR use steel braided brake hose with a non-rubber sleeve (usually Teflon) to greatly reduce the diffusion process.
_________________
93 K1100RS
60K miles now. 30K by me.

Flying Duck · Posted: Fri May 01, 2009 1:30 pm Post subject:

This is almost as good as on oil thread. Laughing

_________________
93 LT (x2)
94 RS
86-97 K75F(K75/100/1100 Frankenbrick)
86 K75C w/paralever, hi perf cams,TURBO!
91 & 92 K75Ss
91 K1
86 custom K100
14 WR250R
IBA #17739 (SS1K, BBG, 50CC)
Buy parts HERE

Jim · Posted: Fri May 01, 2009 3:28 pm Post subject: brake fluid

endoman100 · Posted: Fri May 01, 2009 3:45 pm Post subject:

Because it;s your life that is at risk do anything you can to make yourself safe Very Happy

_________________
In the words of the stones
Time Is On My Side
Yes It Is
1993 K1100RS

phydeauxbytes · Posted: Fri May 01, 2009 4:06 pm Post subject:

Stoked Steve · Posted: Fri May 01, 2009 7:27 pm Post subject:

Thanks for the reassurances of using synthetic, as long as it is DOT4, not the DOT5.
_________________
Steve
Virginia Beach, VA
93 K1100RS Mystic Red SOLD
12 Suzuki DL650A VStrom

Mystic Red · Posted: Fri May 01, 2009 9:38 pm Post subject:

Does the dot 4 synthetic peel paint?
_________________
Scott Hespelt, '94 K11LT
K11 OG #466

Stoked Steve · Posted: Fri May 01, 2009 9:59 pm Post subject:

I'm not about to find out!
_________________
Steve
Virginia Beach, VA
93 K1100RS Mystic Red SOLD
12 Suzuki DL650A VStrom