Rear Brakes - None!

[spke]

For the second time in a month now, riding some twisty's, I've lost my rear brakes. They come right back as soon as I stop (or stop using them). Only happens/happened on downhill twisties.

 

I've been riding twisties for a while now and consider myself fairly competent at it. I have ridden twisties on this bike before and not had any issue. I tend to use front and back in combination to shed speed getting set-up for a turn and then a bit of trailing rear brake into the beginning of a turn as needed. Pretty sure my technique hasn't changed in the last 2 months (hit some twisties hard about 2 mo's ago with no issues) so looking for suggestions on where to start looking.

 

Pads are about 50% life left. Have not changed the fluid since getting this bike.

 

sp!ke

[Condor]

My guess would be air still in the line. Heats up, expands, and gets mushy.... Cools off when not used and contracts enough to give you some pressure.... I installed a Speed-Bleeder in the rear caliper of my '99. Piece of cake getting the air out.....

[Guest]

You boiled your fluid. The Venture is a heavy bike and those rear brakes do heat up quickly. Time to flush your brake system with some fresh DOT4 or DOT 5.1, which has a higher boiling point. Also a good time to flush out the clutch fluid.

[etcswjoe]

:sign yeah that::sign yeah that:

[spke]

Figured that flushing and reloading w/ fresh fluid would be my 1st step. Not sure on the DOT5 tho, IIRC the cover and/or Yam Manual or Clymers maybe says not to use anything above DOT4?

 

You boiled your fluid. The Venture is a heavy bike and those rear brakes do heat up quickly. Time to flush your brake system with some fresh DOT4 or DOT 5.1, which has a higher boiling point. Also a good time to flush out the clutch fluid.

[RandyR]

DOT 5.1 is not the same as DOT 5.

[spke]

Now there's a little tidbit I didn't know. Worth $12 (and maybe my life) all day long.

 

Thanks,

 

sp!ke

 

DOT 5.1 is not the same as DOT 5.

[pmelah]

what is the differnce between dot 5 and dot 5.1 other than the .1 behind the five

 

where can you get the dot 5.1 and what kinda price is on it

[Flyinfool]

DOT 5.1 IS compatible with DOT 3 & 4. and does not contain silicone.

DOT 5 is NOT compatible with DOT 3 & 4 or possibly the rubber parts of the system and contains silicone.

It is easier and safer from a liability standpoint to just say nothing over DOT 4.

 

NAPA carries DOT 5.1, check your local auto parts store or speed shop.

You have to check close because some websites list it as DOT 5 but the small print or the container will say DOT 5.1.

[djh3]

Well had very simular problem today. We were riding here in NC on Wayala road I think they call it between Franklin and Andrews. I was following a bonehead in a Land Rover going down hill. Iwas in 3rd I think and was gaining on him. So had to break hard n long a couple times. Pedal got soft feeling so downshifted a gear and next corner nothing. Tried to pump couple times, no help. So rode 5~ 10 min in 1 and 2nd. Then rears felt ok. Stopped to ck for leaks when I could and all clear. Was ok the rest of the 40 or so miles back. Im on a trip and tools very limited, like bike tool kit only. Really would like to go to cheahola skyway but kinda spooked. I think the dragon is off the list. Any thoughts?

[Guest scarylarry]

Well had very simular problem today. We were riding here in NC on Wayala road I think they call it between Franklin and Andrews. I was following a bonehead in a Land Rover going down hill. Iwas in 3rd I think and was gaining on him. So had to break hard n long a couple times. Pedal got soft feeling so downshifted a gear and next corner nothing. Tried to pump couple times, no help. So rode 5~ 10 min in 1 and 2nd. Then rears felt ok. Stopped to ck for leaks when I could and all clear. Was ok the rest of the 40 or so miles back. Im on a trip and tools very limited, like bike tool kit only. Really would like to go to cheahola skyway but kinda spooked. I think the dragon is off the list. Any thoughts?

 

 

Want to come here Tuesday I have a rear speed bleeder for your bike will take short time and you could be on the road...It would only cost you my cost of the speed bleeder or you can order me one and have mailed to me..Outside of that no charge..

Edited October 14, 2012 by scarylarry

[stroker ace]

Well had very simular problem today. We were riding here in NC on Wayala road I think they call it between Franklin and Andrews. I was following a bonehead in a Land Rover going down hill. Iwas in 3rd I think and was gaining on him. So had to break hard n long a couple times. Pedal got soft feeling so downshifted a gear and next corner nothing. Tried to pump couple times, no help. So rode 5~ 10 min in 1 and 2nd. Then rears felt ok. Stopped to ck for leaks when I could and all clear. Was ok the rest of the 40 or so miles back. Im on a trip and tools very limited, like bike tool kit only. Really would like to go to cheahola skyway but kinda spooked. I think the dragon is off the list. Any thoughts?

 

 

Yep stay off the rears so much use more front brake, or just slow down.

[twigg]

If there was much in the way of air in the lines you would feel it all the time. The brakes would simply be spongy even when cold.

 

What you have is water in the brake fluid. When it heats up, the water turns to steam which is highly compressible, hence the brake fade.

 

Flush through with DOT 4. Bleed correctly and all should be well.

[djh3]

Hum dont know how water would get in. I just put new pads in rear . Really dont have tools to bleed brakes with me. Thanks for offer of speed bleeder but dont see getting over to that part of Tn. Think we may go over to brideal vail falls, Highlands Dillard tomorrow. See how it goes. Never had this problem before, and rode some more agressive braking roads this summer and it was hotter. I do have more weight this time though.

[Guest scarylarry]

Wouldn't moisture form by the fluid getting hot then cold

[twigg]

Hum dont know how water would get in. I just put new pads in rear . Really dont have tools to bleed brakes with me. Thanks for offer of speed bleeder but dont see getting over to that part of Tn. Think we may go over to brideal vail falls, Highlands Dillard tomorrow. See how it goes. Never had this problem before, and rode some more agressive braking roads this summer and it was hotter. I do have more weight this time though.

 

Brake fluid is hygroscopic. It absorbs water from the atmosphere and no brake systems are fully sealed.

 

The problem would be worse in a humid climate, and not helped if the brakes were last filled from an old container of fluid.

 

Flush them with fluid from a fresh container.

 

Manufacturers recommend that fluid is changed every two years. Changing it annually is probably a good routine and the stuff is very cheap.

[djh3]

So looked at autozone web site. No listing for 5.1 fluid. Only dot 4. If i figure I can do this in a parking lot with no tools.

[stroker ace]

Hum dont know how water would get in. I just put new pads in rear . Really dont have tools to bleed brakes with me. Thanks for offer of speed bleeder but dont see getting over to that part of Tn. Think we may go over to brideal vail falls, Highlands Dillard tomorrow. See how it goes. Never had this problem before, and rode some more agressive braking roads this summer and it was hotter. I do have more weight this time though.

 

 

Here is the brake fluid I use,( ATE Super Blue ) you can shop around for best price. I got from this place last time http://www.raceshopper.com/ate_brake_fluid.shtml.

It will help with the rear brake fade when riding hard and loaded up but they will still fade. I use more rear brake than I should and also get rear brake fade. Had brake fade yesterday rear rotor temp around 600* degrees.

 

Most 5.1 fluids dry boiling are around 518* degrees the super blue is around 536* degrees. Here is a list of brake fluids that are out there.

 

 

ARRANGED BY DRY BOILING POINT(some prices from my 2010 list and some are updated, check with your favorite supplier, and look for case prices so you can change it often):

 

DRY:401F -- WET:284F --- DOT3 MINIMUM (GLYCOL BASE)

DRY:446F -- WET:311F --- DOT4 MINIMUM (GLYCOL BASE)

DRY:500F -- WET:356F --- DOT5 MINIMUM (SILICONE BASE)

DRY:500F -- WET:356F --- DOT5.1 MINIMUM (GLYCOL BASE)

DRY:500F -- WET:???F --- FORD HEAVY DUTY DOT 3 PM-1C (new since 2006)

DRY:527F -- WET:302F --- AP RACING 551 ($12.799/0.5L OR 16.9 OZ)

DRY:527F -- WET:347F --- VALVOLINE SYNPOWER DOT3 & DOT4

DRY:536F -- WET:388F --- ATE SUPERBLUE/TYP200 ($13.99/1L)

DRY:550F -- WET:284F --- FORD HEAVY DUTY DOT 3 PM-1 (pre 2006) ($4/12 OZ)

DRY:570F -- WET:284F --- WILWOOD 570 ($7.95/12 OZ)

DRY:570F -- WET:284F --- PERFORMANCE Friction Z rated ($6.27/16 OZ)

DRY:572F -- WET:410F --- AP RACING 600 ($19.95/0.5L OR 16.9 OZ)

DRY:590F -- WET:???F --- TILTON TBR-1 ($11.95/0.25L) (new since 2006)

DRY:590F -- WET:518F --- CASTROL SRF ($74.99/1.0L 0R 33.8 OZ)

DRY:593F -- WET:421F --- MOTUL RBF 600 ($15.99/0.5L OR 16.9 OZ)

DRY:601F -- WET:399F --- BREMBO LCF 600 PLUS ($19.95/0.5L OR 16.9 OZ)

DRY:608F -- WET:390F --- AP RACING PRF660 ($29.95/0.5L OR 16.9 OZ)

DRY:610F -- WET:421F --- NEO SYNTHETICS SUPER DOT 610 ($11.95/12 OZ)

DRY:613F -- WET:424F --- ENDLESS RF-650 ($33.00/0.5L OR 16.9 OZ)

DRY:617F -- WET:399F --- MOTUL RBF 660 ($28.99/0.5L OR 16.9 OZ)

DRY:617F -- WET:383F --- PFC RH665($28.99/0.5L OR 16.9 OZ)

DRY:622F -- WET:???F --- TILTON TSR-1 ($17.95/0.25L) (new since 2006)

DRY:626F -- WET:???F --- FERODO FSF050 Super Race Brake Fluid ($39.99/0.5L OR 16.9 OZ)

DRY:626F -- WET:417F --- WILWOOD EXP 600 ($18.99/0.5L 16.9 OZ)

DRY:635F -- WET:???F --- BREMBO HTC 64T ($32.00/0.5L 16.9 OZ)

DRY:635F -- WET:430F --- PROJECT MU G/FOUR 335 ($45.00/1.0L 33.8 OZ)

DRY:683F -- WET:439F --- PROSPEED RS683 ($39.99/0.5L OR 16.9 OZ)

 

ARRANGED BY WET BOILING POINT:

 

DRY:500F -- WET:???F --- FORD HEAVY DUTY DOT 3 PM-1C (new since 2006)

DRY:590F -- WET:???F --- TILTON TBR-1 ($11.95/0.25L) (new since 2006)

DRY:622F -- WET:???F --- TILTON TSR-1 ($17.95/0.25L) (new since 2006)

DRY:626F -- WET:???F --- FERODO FSF050 Super Race Brake Fluid (new since 2009)

DRY:635F -- WET:???F --- BREMBO HTC 64T

DRY:401F -- WET:284F --- DOT3 MINIMUM

DRY:570F -- WET:284F --- WILWOOD 570

DRY:570F -- WET:284F --- PERFORMANCE Friction Z rated

DRY:550F -- WET:284F --- FORD HEAVY DUTY DOT 3

DRY:527F -- WET:302F --- AP RACING 551

DRY:446F -- WET:311F --- DOT4 MINIMUM

DRY:527F -- WET:347F --- VALVOLINE SYNPOWER DOT3 & DOT4

DRY:500F -- WET:356F --- DOT5.1 MINIMUM (GLYCOL BASE)

DRY:500F -- WET:356F --- DOT5 MINIMUM (SILICONE BASE)

DRY:617F -- WET:383F --- PFC RH665 (new since 2011)

DRY:536F -- WET:388F --- ATE SUPERBLUE/TYP200

DRY:608F -- WET:390F --- AP RACING PRF660

DRY:601F -- WET:399F --- BREMBO LCF 600 PLUS

DRY:617F -- WET:399F --- MOTUL RBF 660

DRY:572F -- WET:410F --- AP RACING 600

DRY:626F -- WET:417F --- WILWOOD EXP 600

DRY:593F -- WET:421F --- MOTUL RBF 600

DRY:610F -- WET:421F --- NEO SYNTHETICS SUPER DOT 610

DRY:613F -- WET:424F --- ENDLESS RF-650

DRY:635F -- WET:430F --- PROJECT MU G/FOUR 335

DRY:683F -- WET:439F --- PROSPEED RS683 (new since 2010)

DRY:590F -- WET:518F --- CASTROL SRF

 

 

Some fluids on the manufacturer's web site did not specify wet boiling point, so I used the relevant DOT 3 value.

 

Water absorption:

DOT 3: This brake fluid has a glycol base with additives. It is clear to amber in color. It is hygroscopic (meaning it absorbs moisture) and has a minimum dry boiling point of 401F (205C) minimum and a minimum wet boiling point of 284F (140C). It will absorb 1 to 2 percent of water per year depending on climate and operating conditions.

 

Castrol SRF remains as always the Wet boiling champ. I don't know of any other new ones.

 

Now of course boiling temp is not the only thing to consider, as compressibility, water absorption rate, recovery, viscosity index, etc all play a part. But without a brake dyno, that data is hard to get.

[V7Goose]

Most of the relevant information has already been given by others, so I'll just recap -

 

MOST important is to CHANGE YOUR BRAKE AND CLUTCH FLUID REGULARLY! The manual specifies every two years, but it seems that few people actually do it - ever.

 

ALL glycol fluids absorb water from the air. ANY brownish color to the fluid at all shows it has a large content of water - the darker it is, the more water there is. In the brake system, this comes through the pores in the rubber lines as well as the vent in the master cylinder. The more you use it, the faster is sucks up moisture (from the constant compression, flexing of the lines, and air getting sucked into the vent). This is why your clutch fluid gets brown much faster than your brake fluids.

 

Brakes generate a huge amount of heat under heavy use, and this is transmitted directly through the pads to the slave cylinder pistons and into the fluid. If there is significant moisture in the fluid, it boils into vapor, which is highly compressible (just like air). This means when you step on the brakes it just squeezes the vapor together a bit but never reaches the pads. After the fluid cools, all seems fine again.

 

Flush the system with fresh DOT4 fluid and your problem is solved. You should always use a new sealed can of fluid, even if you had a lot left over from your last brake service several years ago - once the seal is broken on the can, it will begin absorbing moisture as it ages on the shelf. If you are cheap like me and really hate to throw away the remaining new fluid, you can seal the can lid with hot-melt glue - that generally keeps it fresh. (This trick also works perfectly for any tube of glue, such as tire patch solvent.) The glue seals the cap perfectly, but is still very easy to scrape off when you want to open it again.

 

In my personal opinion, there is absolutely no significant added value from DOT5.1. DOT4 is all you ever need in the brakes if you change it at the recommended interval, and in the clutch, DOT3 is just fine if you do not happen to have DOT4 on hand. I'd much rather have fresh DOT3 in any system than really old DOT4! And the wet clutch combined with the minor heat transfer available to the clutch slave cylinder (will never get hotter than the engine oil) means that DOT3 wet boiling point is never going to be an issue. But the bike spec is still for DOT4, so that is the preferred fluid, even in the clutch.

Edited October 14, 2012 by V7Goose

[spke]

I finally got a chance to pull the rear caliper and found that the pads (organic) were on thier last legs. I put a fresh set of EBC HH on and have yet to do any kind of riding that would allow me to check for fade. At the top of my list is to flush and refill with some fresh DOT4.

 

Need to inspect the front pads and replace if needed. Once that is done I plan to flush and refill Rear, Front, and Clutch.

 

Thanks for all the advice. Will now make it part of my yearly winter maint.

 

sp!ke

[djh3]

Well was OK today no fade. But tookit easy too. I think flushing hyd systems will be high on the list. What is the difference between wet/dry boiling point. I would think the higher the boil point the better performance. So arr some dot 4 higher boil point? I havent looked but is there a rear brake upgrade? Is that something to look into?

[Guest scarylarry]

I have the same make as you flush them once a year and check pads every 8 to 10k miles and I never had a problem...

 

Get speed bleeders and your nerves will love you for it..

[V7Goose]

Well was OK today no fade. But tookit easy too. I think flushing hyd systems will be high on the list. What is the difference between wet/dry boiling point. I would think the higher the boil point the better performance. So arr some dot 4 higher boil point? I havent looked but is there a rear brake upgrade? Is that something to look into?

Dry boiling point is the temp where you get a problem with fresh fluid. Wet boiling point is where the problems starts after the fluid has absorbed water.

 

The boiling point is a safety issue, it has nothing to do with "performance", at least not in the way I define the term. All fluids will "perform" just fine when below the boiling point, and when the system reaches the boiling point, your brakes are simply gone until they cool off.

 

Old brake fluid generally does not give you any hint that it is bad until your brakes suddenly disappear one day from heavy use.

 

The dry boiling point of any fluid (even DOT3) is just dandy, and you will NEVER have any problems at all if you simply change your fluid at the specified intervals. But the higher wet boiling points of DOT4 provide a margin of safety if you neglect your scheduled maintenance or use contaminated fluid. And THAT is exactly why they created DOT4 in the first place, because most people NEVER change their brake fluids, especially in passenger cars and light trucks. Even people who know something about it tend to just ignore this basic maintenance.

 

I am as guilty of this as most people for my cages - I have a 19 year old truck that has NEVER had the fluid changed! The truck rarely gets used, so it is easy to never think about it. But I am glad this thread came along, 'cause now that I am getting ready to move and the truck will be getting some really heavy loads and long 10 hour days on the highway, I'm damned sure gonna change that fluid in the next couple of weeks! And it doesn't matter to me if the spec for it calls for DOT3 or DOT4 - it will get the cheapest DOT4 fluid on the shelf at the discount auto parts store I normally use.

 

So the bottom line for me is simply this - one should always change their brake fluid regularly, at least within the specified schedule for the vehicle. And any DOT4 rated fluid is just peachy-keen for any and all cars, light trucks, and motorcycles that do not specify DOT5 (which is not compatible with DOT4, so they cannot be mixed or the systems easily converted safely).

 

Ride safe,

Goose

[twigg]

Dry boiling point is the temp where you get a problem with fresh fluid. Wet boiling point is where the problems starts after the fluid has absorbed water.

 

The boiling point is a safety issue, it has nothing to do with "performance", at least not in the way I define the term. All fluids will "perform" just fine when below the boiling point, and when the system reaches the boiling point, your brakes are simply gone until they cool off.

 

Old brake fluid generally does not give you any hint that it is bad until your brakes suddenly disappear one day from heavy use.

 

The dry boiling point of any fluid (even DOT3) is just dandy, and you will NEVER have any problems at all if you simply change your fluid at the specified intervals. But the higher wet boiling points of DOT4 provide a margin of safety if you neglect your scheduled maintenance or use contaminated fluid. And THAT is exactly why they created DOT4 in the first place, because most people NEVER change their brake fluids, especially in passenger cars and light trucks. Even people who know something about it tend to just ignore this basic maintenance.

 

I am as guilty of this as most people for my cages - I have a 19 year old truck that has NEVER had the fluid changed! The truck rarely gets used, so it is easy to never think about it. But I am glad this thread came along, 'cause now that I am getting ready to move and the truck will be getting some really heavy loads and long 10 hour days on the highway, I'm damned sure gonna change that fluid in the next couple of weeks! And it doesn't matter to me if the spec for it calls for DOT3 or DOT4 - it will get the cheapest DOT4 fluid on the shelf at the discount auto parts store I normally use.

 

So the bottom line for me is simply this - one should always change their brake fluid regularly, at least within the specified schedule for the vehicle. And any DOT4 rated fluid is just peachy-keen for any and all cars, light trucks, and motorcycles that do not specify DOT5 (which is not compatible with DOT4, so they cannot be mixed or the systems easily converted safely).

 

Ride safe,

Goose

 

This is all you will ever need to know about brake fluid.

 

Well said!

[stroker ace]

This is all you will ever need to know about brake fluid.

 

Well said!

 

 

I will agree to a point, for the average rider or non aggressive rider this will hold true IMHO. Those that ride more aggressive or spirited ( called where I live ) you would see a difference by buying a better ( higher grade ) DOT 4 because of the boiling point difference and less brake fade.

 

I have a track only bike and have seen caliper temps as high as 700* degrees at times but using the Prospeed fluid never had brake fade as of yet. When you can out brake someone corner after corner it adds up. Fluid gets changed before every race and pads every other. Would I do this on a street only bike no but I do spend the extra few bucks for the better fluid for when I do ride spirited yes. I also use the HH pads for the same reason Better braking ability. again IMHO

 

I change brake fluids twice a year in all my vehicles including the tractor. Have a brake bleeding party switching between the ATE amber and blue fluids you can see when fully flushed.