Brake fluid change.

[Buckster]

I'm going to do the brake fluid change and bleed. My first time. I've ordered a mityvac to help this process. My questions are the DOT4 I'm finding at the auto parts store seems to be synthetic and I read that you are not supposed to use synthetic and how is a dot3 and 4? Are these OK to use or do I need to go to BMW for this dot4 non-synthetic or will Honda, Kawi, etc. have this?
I bought a 12oz. bottle of dot3/4 synthetic and wondered if this is OK and also, is it enough to do the front and back brakes.
Any help is appriciated!

[Boxer]

NAPA sells the DOT 4 regular. I wouldn't use the synthetic. I don't know why. I just wouldn't. And if you're careful, one bottle should be plenty.

[Sunbeemer]

Dot 4, non-synthetic brake fluid is what is recommended. Dot 4 should not be a synthetic. (BTW, Dot 5 is silicone -based brake fluid, but I believe there is a new DoT 5.1 that is not) Anyway, Do Not put silicone brake fluid in your systems (brake or clutch). It does not mix with the non-synthetic fluid in there and will be a very expensive mess to undo.

I use Dot3/Dot 4 Castrol Brake fluid for my annual brake and clutch fluid changes.
And don't get it on any paint, it eats it.

[HikerGlenn]

Where did you read that synthetics shouldn't be used? I just renewed my entire brake system (ABS) and clutch with the Castrol GTLMA synthetic based (made in Germany!)fluid. It says right on the bottle that it's fully Dot 3 & 4 compatible and recommended for ABS systems. My BMW dealer uses this, so I figure it must be fine to use. And boy, you ought to feel the brakes now!-Glenn.

[Buckster]

I read it on http://home.mindspring.com/~jabrooks/ on the mainainence guide.
The Valvoline dot3&4 synth. I bought says that it is compatible for all braking systems requiring dot or 4 fluids and says for all ABS and disc and drum brake systems.
I thought it would be fine but I wanted to be sure.
I may return this and go to NAPA if not.

[iowabeakster]

Buckster,

Hikerglenn is correct. I believe it will say on the back of the bottle that it fully compatible with conventional fluid. I think you will find it difficult to locate conventional DOT 4 anymore. I've looked and couldn't find any at the auto parts stores, it seems to have become obsolete. However, I ended up shopping for brake fluid on the way home from work (because of a brain fart), at 4 AM. Wal-mart had some conventional DOT 4, I bet it was on the shelf for a while. Like sunbeemer said, stay away from the DOT 5/silicone stuff.

What you have is exactly what you want.

[CycleRob]

I just bought a 12oz bottle of Prestone DOT4 at Wal*Mart today!! It IS synthetic -but- it is NOT silicone based. It was $2.47 +tx. I believe the problem with DOT 5.0 being used in DOT 3/4 systems is with seal compatibility (rubber piston bands).

Motul Dot 5.1 is not silicone based and has been around for at least 8 years. It was all we used in my shop for street bikes. It has higher boiling points than Dot 3 and 4.

Like Boxer said, the 12oz bottle is plenty if you use the right procedure.

.

[Buckster]

Thanks guys. Appriciate the help.

[boxermania]

DOT 3/4 is a direct replacement for either DOT 3 and DOT 4

DOT 5 is silicone based and not to be used with any of the other DOT specs

Dot 5.1, a fairly new formulation is compatible with both DOT 3 and DOT 4


This article is from the Ducatis Motorcycles FAQ, by Duke Robillard [email protected] with numerous contributions by others.

"Should I use DOT 3, 4 or 5 brake fluid when replacing?"

(Thanks to Michael Ragsdale, from the race list, for some of this info.)

DOT 3 and DOT 4 are functionally very similar. 4 has a higher boiling
point, but motorcycle brake systems don't generate the kind of pressure and
temperatures that need it on the street, in general, although it certainly
won't hurt your system to put it in.

DOT 5 is very different--it's silicone based, doesn't absorb water, isn't
corrosive, is bad for some seals, is hard to bleed, and is not miscible
with 3 or 4. Stay away from it--it needs a system designed for it. And it
comes as stock item in Harley's, so it must be terrible. :->

DOT 5.1 is compatible with DOT 3 & DOT 4 (If I ever get hold of the
bonehead who named DOT 5.1...)

Here's more detail than you really want:

DOT3 is an aliphatic polyether.
DOT4 is borate ester based.
DOT5 is polydimethylsiloxane (silicone based).
DOT5.1 is borate ester based, thus its compatibility with DOT3 and
DOT4.

More information can be obtained from the following standards documents:

DOT3: SAE J1703
DOT4: FMVSS 116; proposed SAE standard J1704
DOT5: SAE J1705
DOT5.1: No SAE spec

If you are interested in obtaining copies of these standards documents, you
may order them directly from SAE at
http://www.sae.org/PRODSERV/STANDARD/gv/179.htm

According to DOT Federal Motor Vehicle Safety Standards specification
49CFR571.116 (which refers to SAE documents J1703, J1704, J1705), the
minimum equilibrium reflux boiling point requirement in deg C for each is:

DOT 3 205
DOT 4 230
DOT 5 260
DOT 5.1 260

This shows that, all else remaining the same, DOT 5.1 has a significant
advantage in heat capacity over DOT 4. Note that these specifications are
for completely dry (no H2O content) brake fluid.

Of course, all else does not remain the same and other than boiling points
and H2O content (which is very detailed in itself), most other properties
were beyond the scope of testing/interest of my friend. Any other
information should be gained from SAE, DOT or other authority.

[Boxer]

Brian, et al...This thread needs to go into the FAQs section. Just a suggestion.

[FloridaBeakster]

Non-synthetic DOT4 is readily available in a variety of sizes at NAPA.

[philbytx]

Just a quick point...
Some fluids have higher dry and wet boiling points than others....especially fluids for higher performance applications.
The higher the wet boiling point, the better for braking IF you leave your fluid in a little longer than you should. Brake fluid adsorbs water and a lower wet boiling point will boil your brakes a a lower temp, should you leave it in longer and more water is adsorbed.
I use Ate Typ200 (Gold colour) and Blu (Blue in colour) in my BMW bikes and cage as this has higher Dry and Wet BP's. I alternate the types with each change (easier to see when its flushed through) and have done so for years.

[Buckster]

philbytx,
Where do you buy that from? Sounds like a good idea with the colors for a first timer.

Also, I received my Mityvac yesterday and nowhere does it tell you how to clean it. Will hot soapy water clean out the brake fluid in the tubing and reservoir or is something else better to clean it with?
Thanks again to all for the info!

[Buckster]

Also...can I use the black rubber fitting? It does go over the fitting on the brake. The directions don't say what it's for. It says to use the smaller diameter tubing 5/16" I believe to push onto the brake fitting. It does go on very tight. I guess thats why they call for that to go on.
Thanks.

[challey]

Buckester said:

. . . I received my Mityvac yesterday and nowhere does it tell you how to clean it.

Unless you are using it for other applications, you really shouldn't need to do anything but wipe it down before storing it. If you do need to clean it, I'd try some Simple Green.

As far as using the Mityvac, I just push the clear hose over the nipple and cinch it down with a resusable zip tie.

I hope that the issue of synthetic vs non-synthetic is settled. For the record, I've used Castro GTLMA DOT 4 - the same synthetic as Hiker Glenn used - for several fluid changes over the past 5 years with good results.

Charlie

[philbytx]

I get mine from the following folks :
http://www.ogracing.com/catalog/2-Car/3 ... RAKE-FLUID
Brake fluid is a soapy water clean-up....but do ensure that you keep everything clean and dry after!

philbytx,
Where do you buy that from? Sounds like a good idea with the colors for a first timer.

Also, I received my Mityvac yesterday and nowhere does it tell you how to clean it. Will hot soapy water clean out the brake fluid in the tubing and reservoir or is something else better to clean it with?
Thanks again to all for the info!

[bmwdave52]

I use Valvoline Dot 3 and 4 synthetic. No problems the last four years.

You Mityvac users are going to LOVE this: My wife is a Labor and Delivery RN and they use a Mityvac to help deliver the baby.
How would you like to clean that vac?!

[Twempie]

If you're going to do this by yourself, consider getting some Speedbleeders. I do most of my work alone and I found the MightyVac to be messy and awkward.

I installed stainless Speedbleeders last week, I haven't bled the brakes with SB's yet because it isn't due. But by all reports on the MOA site, they work well. If you do get some, make sure you get two for the front discs and, this is important... make a note on the order form about which model of bike they're going on. Speedbleeder's website has two differing size charts that contradict each other, if you tell 'em what bike you have, they'll give you the correct parts.

[Buckster]

Thanks for all the help. Took me about an hour and a half because I was really taking my time and doing things right.
I used plastic stretch wrap to cover the bike in the areas where the bleeding was taking place. I could probably do it in about 40 minutes next time. Taking the rear panel to get to the rear brake reservoir took the longest.
The Mityvac was a good investment. Twempie, it is a little akward until I figured that using a 5 gallon bucket to set it on and twisting the pump 90 degrees so that the tool would lay flat on the bucket and the reservoir would hang off the side of the bucket worked very well.

Now I just need to learn how to do the clutch bleed, valve adjustment, and TB balance!
Thanks for all the help!!

[Twempie]

You have to take the whole ass-end off the bike to bleed the clutch and it doesn't need to get done "just because".

The valve adjustment is pretty easy. I'm a Clymer and LIOTI (learned it on the internet) type of guy, and I bought a DVD from Jim Von Baden, over at the MOA. http://www.jimvonbaden.com/service2.aspx This low-budget video shows a few basics on home wrenching. It helped me with the valve adjust.

Just make sure you remove the spark plugs when rotating your rear wheel (in 6th gear) to find TDC. I tried it with the spark plugs still installed and, managed to find TDC, but it was very difficult to rotate the wheel, I removed the plugs and it was easy. Such are the experiences of a LIOTI.