synthetic brake fluids ok??

[go-n-postl]

Hope this is in the right section as this isnt truely a lubricant. Has anyone used sythetic brake fluid in their bike. I was thinking of using Valvoline synthetic(gold bottle, If I remember correctly) brake fluid in mine. I use to use it in my postal jeep and it really helped with brake fade once the brakes heated up with all the stop and go I had to do. It also lasted alot longer than conventional fluids. I use it in all my 4 wheelers. I went to look but I didnt have a bottle handy to read all details. If I remember correctly it is compatable with all flavors of fluid(ie dot 3,4,5). Does any one know if this will work or not? Will using anthing other than HD hurt the seals/gasket ? Im not having problems with my brakes. I just dont know what was actually done to the bike (or when) prior to me getting it. So I am concidering changing out all the fluid in both resevoirs. will it work??? TIA --timf

[FSZEKE302]

Don't know, but I hope someone does. Sounds like a good thing to me, if the seals will accept it.

[indyrednek]

Only put what the cap on you mastercylinder says.
If it is DOT 4 or 5. I cannot remember my bike is at home right now.
Do NOT use anything else. You can cause brake lock-up or failure.
If you use something other that what the specs say to use you can be in a worl pf hurt and extra $$$.
We have customers bring their trucks/cars in and have put something else in and it cause major problems.
The repairs for that were in the excess of $2000.
Just be careful and read the owners manual and/or service manual.

[hawgzotic]

harleys use dot 5

dot 5 is a synthetic

DO NOT USE ANY OTHER FLUID THAN DOT 5 OR YOU WILL RISK FATAL INJURY!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!

that includes dot 5.1

i repeat do not mix dot 5 fluid with any other fluid.

[go-n-postl]

Well I went to Advance auto and picked up a bottle of the fluid. I wont be using that one in the bike as it is dot3/dot4. still needed some for the cars. I guess i could have saved time and got off my but and went to the part store. Guess I got a good reason to go to HD tommorow. I dont need an excuse but I will at least have a destination when i go out now. Thanks for the replies -- tim f

[Moved On]

Yep no mix em together. I've heard that it will gel up into a gunky semi solid goo if you mix them :yikes

Gazza

[honus402]

Sporties use DOT 5 which is a pure silicone synthetic. Don't mix it with anything else.

[FSZEKE302]

Thanks Guys, I,m going to flush my system and put new pads on soon. Dot 5 it is. Best pads? I'm leaning to SBS. Welcoming suggestions.

[AZbiker]

I ran some SBS pads once. I usually get 5k out of the stockers, the SBS went 3k and threw off a lot of dust.

They do have a nice initial bite though. Like sticky tires, the more friction the brake pad material has, the shorter they last, I think.

I personally run stockers now, and see no reason to switch.

[nzsailor]

uuuuummmmmmmmmmm........
if i may point out
it aint what is marked on the reservoir that matters
its what someone has put in the reservoir that matters
i wrestled with this prob a while after i got my bike
mine is marked dot 5 but had dot 3 in it
refilling with dot 5 would have been dangerous
if you dont know the history of the bike take a small sample of the fluid thats in there now and test it
dot 3, 4, n 5.1 will bubble paint and mix with water
dot 5 will not bubble paint nor mix with water
if you want to change you have to completely flush the system with pure alcohol
i know of no fluid that is compatible with both and of what i know of chemistry which is lamentably little i cant conceive of anything that would be
use extreme caution
either an unexpected locking or complete loss of brakes could be expected from using an incompatible fluid

[johnric]

Hi !! i work as a mechanic (saab) in Tromsø North norway and i have som thing to say that i read on the internett and some personel experianse!! (sorry for my english) :-)
Dot 5 break fluid i sillicone based (very expensive) but dot 5.1 aint, its`s glycol based and mutch cheaper. They both have the same boiling point ca 270 celsius.
They wont mix! but you can use dot 5.1 because the gaskets in the breake system on newer harley wont be destroyed.(remember to flush out the system and don`t use any thing that eat`s up rubber when you flush out your system, i only used break fluid to flush out my system)
But beaware of the paint! glycol based break fluid eats up the paint but sillicon dosen`t!
Owner of a sportster 1995 1200!

[H@mbone!]

Oreillys auto parts sells DOT 5 can't remember the price but it is a little cheaper then from the dealer. Also walmart sells it I believe. Oreillys is made by Gunk. Thats what I used on my bike. Have not had any problem with it. I also used 20-50 Castoral Syntec for my oil. Don't know if you can use it, Harley said it would be alright so I guess thats the answer I will go by.

[Takingabreak]

harleys use dot 5

dot 5 is a synthetic

DO NOT USE ANY OTHER FLUID THAN DOT 5 OR YOU WILL RISK FATAL INJURY!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!

that includes dot 5.1

i repeat do not mix dot 5 fluid with any other fluid.

:iagree :iagree :iagree :iagree :iagree :iagree :iagree :iagree :iagree :iagree :iagree :iagree :iagree :iagree :iagree :iagree :iagree

[johnric]

what can i say to this but!!!!!!BULLSHIT....YOU CAN USE DOT 5.1 (glycol based break fluid) because the system on newer harley can tolerate it! it wont break!!
But if someone ask`s me i would tell them to use Dot 5 sillicone based break fluid!! I personely use dot 5.1 on my harley ! sportster 1200 1995
sign: a Mechanic

[opiewontaylor]

You can get dot 5 at any good auto parts store. Unless, of course, you just want to go to a Harley dealer.

[SteveB]

Yeah the moco screwed us again by switching to cheapass glycol based fluid.Another ruined paint job, who cares. Buncha newbies don't know history. Another example: Dynas no longer have Timken bearings on the output shaft, the aftermarket can fix that though.It's a problem in that the roller bearings blow out the side on some bikes. Oh well, those bikes (forget the biker) didn't matter anyway! AARRRRRRRRRRRGGHHHH!!!!!!!!!!!!

[chrishajer]

True it matters what is marked on the master cylinder (DOT 4 or DOT 5) and that's what should be used in the system. Dot 3, 4 and 5.1 are similar (glycol based) and DOT 5 is Silicone based. Don't mix one type with the other. As someone posted, it turns to goo and is dangerous.

It also matters what someone might have used previously. If they switched the system over from DOT 5 to DOT 3, then you have to stick with the new fluid. No mixing. If you want to change a system from one fluid to another, you can, so long as you replace all the rubber parts in the system (seals in the caliper and master cylinder, and any rubber lines.)

AFAIK, all XL models since Sept 7, 1977 have used DOT 5 brake fluid. Prior to that was DOT 3.

In 2000 Buell started using DOT4 fluid instead of DOT5, and in 2005 HD started using DOT4 in the FLH models. In 2006, they started using DOT4 in V-Rod, Dyna and Softail models. It's not as simple as it used to be ("all HD use DOT5.") You have to be careful to use the right fluid. They both have a distinctive smell too, so you can tell them apart like that too.

--Chris

[AZbiker]

Yeah the moco screwed us again by switching to cheapass glycol based fluid.Another ruined paint job, who cares. Buncha newbies don't know history.

So placing a towel over the gas tank is impossible? Geez, I wonder how all those import bikes still have good paint jobs! :roflblack

I'm thinking of switching to 5.1 in my bike because of the shite, spongy feel that comes from DOT5. I could spend days bleeding my front brake, there is still sponginess at the lever that shouldn't be there. My last bike with a stainless brake line didn't have that problem. :rolleyes:

[SteveB]

True it matters what is marked on the master cylinder (DOT 4 or DOT 5) and that's what should be used in the system. Dot 3, 4 and 5.1 are similar (glycol based) and DOT 5 is Silicone based. Don't mix one type with the other. As someone posted, it turns to goo and is dangerous.

It also matters what someone might have used previously. If they switched the system over from DOT 5 to DOT 3, then you have to stick with the new fluid. No mixing. If you want to change a system from one fluid to another, you can, so long as you replace all the rubber parts in the system (seals in the caliper and master cylinder, and any rubber lines.)

AFAIK, all XL models since Sept 7, 1977 have used DOT 5 brake fluid. Prior to that was DOT 3.

In 2000 Buell started using DOT4 fluid instead of DOT5, and in 2005 HD started using DOT4 in the FLH models. In 2006, they started using DOT4 in V-Rod, Dyna and Softail models. It's not as simple as it used to be ("all HD use DOT5.") You have to be careful to use the right fluid. They both have a distinctive smell too, so you can tell them apart like that too.

--Chris
So flushing with alcohol isn't good enough?

[SteveB]

So placing a towel over the gas tank is impossible? Geez, I wonder how all those import bikes still have good paint jobs! :roflblack

I'm thinking of switching to 5.1 in my bike because of the shite, spongy feel that comes from DOT5. I could spend days bleeding my front brake, there is still sponginess at the lever that shouldn't be there. My last bike with a stainless brake line didn't have that problem. :rolleyes:

Accidents happen to calipers too.
Agreed, stainless are more solid feeling.
What is the advantage of glycol based ?

[chrishajer]

So flushing with alcohol isn't good enough?
From what I understand, no. Denatured alcohol is fine for cleaning components and reassembling with the same fluid type, but for switching, I was always told that anything rubber needs to be replaced. I don't know if I have a reference for that bit of wive's tale / anecdote though.

I've never done it any other way, and never had a problem. However, I never tried it with alcohol either.

The information may be more applicable to older brake systems with natural rubber seals. It's possible it swelled or shrunk more with one fluid or the other.

[ 5 minute pause while I look through my reference material ]

OK - here's why I believe what I do about the rubber components. These are MMI notes from 1987 :)

http://www.chrishajer.com/bike/XLF/dot3dot5.jpg

Now, whether or not it's true, or if it was some anecdotal BS from them, I don't know. But it's stuck with me all these years. I don't f:censorck around with brakes.

--Chris

[chrishajer]

What is the advantage of glycol based ?
Maybe this will be helpful for comparing DOT 3, 4, 5 and 5.1:
http://www.belray.com/consumer/Q&A%20pages/q&abf.html

They say it far better than I ever would.

--Chris

"You know what I'm thinking without my having to explain to you in fancy terms. We speak each other's unspoken language... fluently."

[cantolina]

Yeah the moco screwed us again by switching to cheapass glycol based fluid.Another ruined paint job, who cares. Buncha newbies don't know history. Another example: Dynas no longer have Timken bearings on the output shaft, the aftermarket can fix that though.It's a problem in that the roller bearings blow out the side on some bikes. Oh well, those bikes (forget the biker) didn't matter anyway! AARRRRRRRRRRRGGHHHH!!!!!!!!!!!!

They switched because DOT 5 is not compatible for ABS systems.....

[chrishajer]

They switched because DOT 5 is not compatible for ABS systems.....
Now, don't go confusing the issue with facts.

You are right, of course.

http://www.raybestos.com/OnLineTraining/cpt-005.htm

--Chris

[AZbiker]

Accidents happen to calipers too.
Agreed, stainless are more solid feeling.
What is the advantage of glycol based ?

I've already got a stainless line. And spent a LOT of time bleeding it. And my brakes still feel slightly spongy (but still a whole lot better than stock). The general consensus over in the cafe groups is that the silicone-based fluid has a slightly spongy feel. Glycol doesn't.

[SteveB]

Thanks guys, I apologize for losing it earlier. Having moonlighted in a shop in '88 to make up for lost OT I saw way to many ruined master cylinders and calipers from mixing glycol and silicone. Some were crystalized and wouldn't work at all. Test rode a tire change... no brakes in back.........cylinder was trash, caliper was rebuildable. The "stuff" inside was a crystaline and sludge mix. The rotor looked unused. never made it off the lot because the back tire locked up in the gravel. Does anyone else feel more comfortable pulling off the side, if there's room, into the gravel when the back tire locks up from a snapped chain or whatever?

[AZbiker]

Thanks guys, I apologize for losing it earlier. Having moonlighted in a shop in '88 to make up for lost OT I saw way to many ruined master cylinders and calipers from mixing glycol and silicone. Some were crystalized and wouldn't work at all. Test rode a tire change... no brakes in back.........cylinder was trash, caliper was rebuildable. The "stuff" inside was a crystaline and sludge mix. The rotor looked unused. never made it off the lot because the back tire locked up in the gravel. Does anyone else feel more comfortable pulling off the side, if there's room, into the gravel when the back tire locks up from a snapped chain or whatever?

Rubber does have a certain amount of porosity. That is why they say to replace all the rubber parts. Because flushing them will not remove all traces of the old fluid. I maintain my brakes good enough to not worry either way. I like the glycol stuff because I know when it gets a little dark it is time for a change.

[cia2a]

Is it true that when you top off the brake fluids you must bleed the brakes or is that bull. The dealer told me this.

Thanks yall

[chrishajer]

That's bull. You only need to bleed the brakes if there's air in the system. Unless you let the reservoir get so low that it let air into the system, you don't have to bleed anything. If the brakes are working fine, just top it off, no bleeding required.

Beware though that as the pads wear, the fluid level in the reservoir goes down. The fluid is now in the caliper pushing the piston out. So if you top if off, when you install new pads, you'll end up forcing fluid back into the reservoir, and there might be too much there to work properly. Just beware that if you top it off now, when you put pads in, there might be too much in the system.

--Chris

[kd4tsc]

It's agreed then!
DOT 5 only.
Does anyone have a brand preference?
I use Mobile 1 V-Twin in the crankcase and primarycase because I don't really believe Harley Davidson set forth parameters in front of their suppliers. I think they're more interested in making a buck, therefore I don't beleive "made to HD specs" means anything. Case in point: This is my first Harley Davidson bike; I went in to HD of Greenville, SC to buy a set of mirrors. I noticed on the package, (which had all of HD black and red lettering, eagle logo, etc...), it said "Made in Taiwan". American eagle! Yeah, right. BTW, HD wasn't the first to use an eagle as oner of their logos.
Sooo..., what Brake Fluid brand does everyone recomend?

[kd4tsc]

It's agreed then!
DOT 5 only.
Does anyone have a brand preference?
I use Mobile 1 V-Twin in the crankcase and primarycase because I don't really believe Harley Davidson set forth parameters in front of their suppliers. I think they're more interested in making a buck, therefore I don't beleive "made to HD specs" means anything. Case in point: This is my first Harley Davidson bike; I went in to HD of Greenville, SC to buy a set of mirrors. I noticed on the package, (which had all of HD black and red lettering, eagle logo, etc...), it said "Made in Taiwan". American eagle! Yeah, right. BTW, HD wasn't the first to use an eagle as oner of their logos.
Sooo..., what Brake Fluid brand does everyone recomend?

[John1200]

It's agreed then!
DOT 5 only.
Does anyone have a brand preference?
I use Mobile 1 V-Twin in the crankcase and primarycase because I don't really believe Harley Davidson set forth parameters in front of their suppliers. I think they're more interested in making a buck, therefore I don't beleive "made to HD specs" means anything. Case in point: This is my first Harley Davidson bike; I went in to HD of Greenville, SC to buy a set of mirrors. I noticed on the package, (which had all of HD black and red lettering, eagle logo, etc...), it said "Made in Taiwan". American eagle! Yeah, right. BTW, HD wasn't the first to use an eagle as oner of their logos.
Sooo..., what Brake Fluid brand does everyone recomend?

Agreed?:laugh I think that you will find as much of a consensus of what brake fluid to use as to what oil to use. There are advantages and disadvantages to both D.O.T. 5 and D.O.T. 5.1. It's a personal preference. Just don't mix the two and if switching from one to the other thoroughly clean system and replace any rubber components (just to be safe).