Break Fluid
#1
04-14-2009, 06:31 PM
Break Fluid
Ok so changed the front break pads the other day , front callipers hadn't been touched for what looked like ages so took them off and gave them a good clean in new break fluid as well , pistons out blah blah.....
So popped them all back on and bled the breaks completely , so all new fluid in the system . The front breaks while they are improved , they have not improved as much as I would have expected .
So two questions:-
So popped them all back on and bled the breaks completely , so all new fluid in the system . The front breaks while they are improved , they have not improved as much as I would have expected .
So two questions:-
- The Haynes manual says to bleed the breaks is a two man job
and that both front callipers should be bled at the same time . Now does this mean simultaneously or does it just mean I shouldn't bleed one and not bother with the other?(I'm as sure as I can be there is no air left in the system). - Is there a real performance difference between different brands of break fluid i.e. will the breaking improve if I use a different brand?
Just to let you know I've ridden about 150 - 200 miles , with plenty of hard breaking so they should have bedded in now right?
Thanks Guys
#2
04-14-2009, 07:18 PM
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Been here Hawk , done this before myself mate..
Gone to the trouble of cleaning them to death , changing fluid and then yup..not much difference.... actually worse if they are not bled completely...
Its just easier with 2 peeps .. I have always done mine separately and had no trouble ..
I always run quite a bit of fluid through into a clean bottle for re capture , so as to make sure no air is trapped ...
The fluid is just the extension of the piston ...so the worst thing that crook fluid will do is make the pressure at the lever feel a bit spongy...
Sure maybe if you race ... but for normal use ... IMO - nup
The new fluid may make it feel a bit more solid but it prolly wont make them, work much better..
(may make them feel as little more positive if the old fluid was dead as a maggot )
OK ..now o'll get jumped on with guys saying ..
" chit no, it makes a chit load of difference
" !!
well its 90% BS unless you ride and brake like the possessed
Clean fluid is safer, because the chance of it boiling or failing is way less ....that's it...
The only thing apart from correct bleeding that I have found that make the brake's feel better is the right pads ! and may be up graded discs (that I have put on other bikes )
RE/ bleeding--
Do your brake's feel spongy now ? or are they solid ?
Gone to the trouble of cleaning them to death , changing fluid and then yup..not much difference.... actually worse if they are not bled completely...
The Haynes manual says to bleed the breaks is a two man job and that both front callipers should be bled at the same time . Now does this mean simultaneously or does it just mean I shouldn't bleed one and not bother with the other?(I'm as sure as I can be there is no air left in the system).
and that both front callipers should be bled at the same time . Now does this mean simultaneously or does it just mean I shouldn't bleed one and not bother with the other?(I'm as sure as I can be there is no air left in the system).
I always run quite a bit of fluid through into a clean bottle for re capture , so as to make sure no air is trapped ...
The fluid is just the extension of the piston ...so the worst thing that crook fluid will do is make the pressure at the lever feel a bit spongy...
Is there a real performance difference between different brands of break fluid i.e. will the breaking improve if I use a different brand?
The new fluid may make it feel a bit more solid but it prolly wont make them, work much better..
(may make them feel as little more positive if the old fluid was dead as a maggot )
OK ..now o'll get jumped on with guys saying ..
" chit no, it makes a chit load of difference
" !!well its 90% BS unless you ride and brake like the possessed
Clean fluid is safer, because the chance of it boiling or failing is way less ....that's it...
The only thing apart from correct bleeding that I have found that make the brake's feel better is the right pads ! and may be up graded discs (that I have put on other bikes )
RE/ bleeding--
Do your brake's feel spongy now ? or are they solid ?
Last edited by CBRclassic; 04-15-2009 at 08:35 AM.
#3
04-14-2009, 07:31 PM
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Posts: n/a
Bleeding the "bloody" brakes
I really like the play on international language....
(title above under the bucket of blood saloon)
Hawk, I have never bled my CBR's brakes, but I have bled quite a few dual front rotor disc brakes (Kz1300, Valkyrie, FXR-P, 1200 Sportster, VL1500, etc). Doing one side at a time is fine. The air that is in one side will come out that side. The air that is in the other side will come out the other side. I bleed the one side until it is clear (new fluid color), then move to the other side. Doing both sides a once would mean half as much fluid out of each side on each stroke of the front master cylinder piston. Any slip one side, while doing both together, could cause air to enter and possibly get into the other side (air bubbles travel up to the main feed line is what I am saying). Some people back bleed the brake system because air travels up, so the air will all be eliminated with the back bleeding method. I think the manual was referring to bleeding both sides and not just one side and calling it good.
(title above under the bucket of blood saloon)Hawk, I have never bled my CBR's brakes, but I have bled quite a few dual front rotor disc brakes (Kz1300, Valkyrie, FXR-P, 1200 Sportster, VL1500, etc). Doing one side at a time is fine. The air that is in one side will come out that side. The air that is in the other side will come out the other side. I bleed the one side until it is clear (new fluid color), then move to the other side. Doing both sides a once would mean half as much fluid out of each side on each stroke of the front master cylinder piston. Any slip one side, while doing both together, could cause air to enter and possibly get into the other side (air bubbles travel up to the main feed line is what I am saying). Some people back bleed the brake system because air travels up, so the air will all be eliminated with the back bleeding method. I think the manual was referring to bleeding both sides and not just one side and calling it good.
Last edited by CBRriderNevada; 04-14-2009 at 07:35 PM.
#4
04-15-2009, 06:31 AM
Thanks for the advice guy's , I kinda figured it would be OK to just do both callipers , but when there wasn't a dramatic improvement my mind got working in the twisted kinda way it does
The brake fluid that came out was dark brown and the callipers were filthy so I was expecting dramatic results
. Pumped about 750ml of brake fluid through so no bubbles and nice and clean
The brakes work well , but the leaver isn't as firm as I expected , so may try another type of fluid in a couple of days , make sure the pads are well and truly bedded - in
The brake fluid that came out was dark brown and the callipers were filthy so I was expecting dramatic results
. Pumped about 750ml of brake fluid through so no bubbles and nice and cleanThe brakes work well , but the leaver isn't as firm as I expected , so may try another type of fluid in a couple of days , make sure the pads are well and truly bedded - in
#5
04-15-2009, 08:00 AM
Brake fluid is hygroscopic, Hawk, ie it retains water - the darker the fluid, the more water (and muck) it contains. Best brake fluid is almost clear, maybe a light champagne colour.
As Steve says, the only time you may feel it is on the track, or they won't fail when they may have due to boiling old fluid, and then you probably won't notice it anyway. I recently replaced my fluids, and no difference in the stopping power, just a bit more peace of mind.....
As Steve says, the only time you may feel it is on the track, or they won't fail when they may have due to boiling old fluid, and then you probably won't notice it anyway. I recently replaced my fluids, and no difference in the stopping power, just a bit more peace of mind.....
#6
04-15-2009, 08:31 AM
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I ended up going to DOT5.1 fluid in my 1991 bike. It is mixable and compatible with DOT4 fluid but has a higher boiling point.
Although there was virtually no difference in feel between DOT4 and DOT5.1 when braking - the clutch felt much smoother using the DOT5.1
A vacuum bleeding tool also seems to do a better job than the old "pumping fluid through with the lever" system.
Although there was virtually no difference in feel between DOT4 and DOT5.1 when braking - the clutch felt much smoother using the DOT5.1
A vacuum bleeding tool also seems to do a better job than the old "pumping fluid through with the lever" system.
#7
04-15-2009, 02:08 PM
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I changed pretty much everything on my brakes also this spring and as i was thinking before now i ma sure of it. The biggest problem is that original tubes does not have metal armor so when pressing hard on brakes it swells and that's why the brakes don't feel so precise as newer sportbikes. Also calipers seemed to move a bit and give some extra slag - but as Classic said its all problems of a racetrack
#8
04-15-2009, 03:31 PM
Maybe I'll fit some braided hoses , there were some on e-bay....hmmm. Nah if it aint broke don't fix it , I'm no Valentino Rossi that's for sure . The brakes work well , I just expected more of an improvement .
I suppose it's a testament to Honda how their stuff still works even when neglected.
I suppose it's a testament to Honda how their stuff still works even when neglected.
#9
04-16-2009, 07:40 AM
Someone mentioned "Piece of mind".........in a nutshell,thats all it is.
We did my Front ,Rear & Clutch fluid in about September last year.Yeah they were all like Guiness,no idea when they were last done?
The big surprise was the build up of "gunk" that sits in the bottom of the fluid well,that creamy gell right near the outlet to the Lines.............Which needs to be carefully wiped out with Cotton buds..
We did my Front ,Rear & Clutch fluid in about September last year.Yeah they were all like Guiness,no idea when they were last done?
The big surprise was the build up of "gunk" that sits in the bottom of the fluid well,that creamy gell right near the outlet to the Lines.............Which needs to be carefully wiped out with Cotton buds..
#10
04-16-2009, 09:00 AM
