brake fluid

[scubasteveRR]

So i'm looking for an opinion on brake fluids, I just got some steel lines and I see there many different DOT 4 fluids out there and DOT 5.1. I've heard that DOT 5.1 is the best but breaks down fast or something like that? I have no idea.

I'm assuming DOT 4 will be fine for street riding and the occasional track day so I started looking and there is a decent differece in the fluid prices...

Repsol - 4.95 a bottle
Motorex - 8.75 a bottle
and
Motul RBF - 19.50 a bottle

From my understanding the Repsol has a boiling point of 311 F and the Motul RBF (which is designed for racing) has a boiling point of 594 F.

Is it worth it to spend double, or ever 3 times the Repsol for these other brands?

[Degsy]

Wirelessly posted (BlackBerry8530/5.0.0.734 Profile/MIDP-2.1 Configuration/CLDC-1.1 VendorID/105)

If you are doing any track work, spend the extra. Otherwise any dot 4 is fine.

[scubasteveRR]

So looks like the Motul RBF is the choice since I will be doing track days...

Now couple other follow up questions, will I need two bottles to fully fill the front and rear?

Also, I am adding speed bleeders while I am at it and I've been told to fill the lines with fluid before the speed bleeders go on because just air doesn't build enough pressure to activate the speed bleeders?

Should I put some regular DOT 4 through and get rid of the air, then put the speed bleeders on and put the Motul in and fully bleed them out with the Motul.

Does this sound like too much? I just want to make sure I don't waste a bottle trying to get the air bubbles out of the lines.

then after fully bleeding I've read to leave your brake lever zip tied for the night?

[DuncanMoto]

Don't switch out to speed bleeders with a disconnected or empty line.
And don't throw out your stock bleeders either. You'll need them again one day.
I would use regular dot 4 to flush the calipers thoroughly before disassembling anything.
Then drain fluid from lines and install your new lines. You do not need to completely drain the calipers.
Bleed as you normally would with your normal bleeders and a mighty vac.
Once you're fully bled system then button up the reservoir cap and switch out to the speed bleeders and tighten them after cleaning very well around the bleeders. Then bleed a minimal amount with the speed bleeders.

Bleed master cylinder 1st.
Get a bleed nipple for the master if you don't already have one. If not you're gonna have to zip tie lever overnight.

[Jim]

I've always used Maxima DOT4. right now i'm using Brembo @ $35/bottle

[scubasteveRR]

Thanks Ted, I actually have a wish list on your site with all the things I want. was going to call you after 2pm when you open to go over an order for me that I would like to just pick up at your shop if it will save me from shipping charges.

Bleed as you normally would with your normal bleeders and a mighty vac.

I don't have a mighty vac, can I just bleed the brake with the stock bleeders, do I really need one of those?

Once you're fully bled system then button up the reservoir cap and switch out to the speed bleeders and tighten them after cleaning very well around the bleeders. Then bleed a minimal amount with the speed bleeders.

Good, this was my exact plan of attack for the speed bleeder installation.

so the answer to my question about the regular brake fluid you said to use the regular brake fluid before changing to the new lines then use the Motul right off the bat and not fill the lines with the cheap stuff to get the air pockets out of the new lines before switching to the Motul fluid.

Bleed master cylinder 1st.
Get a bleed nipple for the master if you don't already have one. If not you're gonna have to zip tie lever overnight.

I have a stock (05 600rr) master, I do not think it has a bleed valve on the master, how would one find if I can put on of those on there?

Also I was told that this would be a good time to do a master cylinder rebuild since my bike just about to be at 20k

[Jim]

steve, mitivac is good for initial bleeding, but do the manual way to finalize. i can give you a hand doing this, as i've done more brake bleeding this season than i should admit

[DuncanMoto]

Yes rebuild that master too.

What brand lines did you get?
I have Galfer double banjo bleeders and can special order them with any kit.

Use the RBF with the new lines. The air bubbles will help you know when you have the old fluid expelled.

[DuncanMoto]

Steve,
Call me now.
617-264-0531

[scubasteveRR]

steve, mitivac is good for initial bleeding, but do the manual way to finalize. i can give you a hand doing this, as I’ve done more brake bleeding this season than i should admit

Good stuff, I will always welcome the help. I'm assuming you have a Mighty Vac? I was planning on doing the line change at my place in Bolton, not sure if that a convenient place of for you to get to from Boston??

I also went with your recommendation on getting either Goodrich or Galfer lines over the Spiegler ones after our chat at the track day a couple weekend ago. I got a deal on the Galfers where I got the rears for free when I bought the fronts so I went with those.

[CBR929RE]

I have a stock (05 600rr) master, I do not think it has a bleed valve on the master, how would one find if I can put on of those on there?

double banjo bolt with integrated bleeder bolt. Ted will know.

[eboos]

so the answer to my question about the regular brake fluid you said to use the regular brake fluid before changing to the new lines then use the Motul right off the bat and not fill the lines with the cheap stuff to get the air pockets out of the new lines before switching to the Motul fluid.

I wouldn't fill with the cheap stuff, but I would use the cheap stuff when cleaning and flushing. If you fill with the cheap stuff, you are just diluting the good stuff that you put in later.

As long as you aren't wasteful and bleed effeciently, one bottle of RBF600 should be good for front and rear.

[Jim]

yes i have a mitivac, but dont use it anymore. i've got a clear hose that i put on the bleeder, so i can see air pockets coming out.

since you're buying some stuff from Ted, pick up a pair of Goodridge speed bleeders.

[Jim]

As long as you aren't wasteful and bleed effeciently, one bottle of RBF600 should be good for front and rear.

if switching lines, rebuilding master/calipers, etc, then start with cheap fluid. once everything is bled and pressurized nicely, then switch over to the expensive stuff. you'll be wasting less of your good fluid & might have enough to use that 1 bottle for the rear also.

[eboos]

if switching lines, rebuilding master/calipers, etc, then start with cheap fluid. once everything is bled and pressurized nicely, then switch over to the expensive stuff. you'll be wasting less of your good fluid & might have enough to use that 1 bottle for the rear also.

Like I said, you are diluting the good stuff with crap if you do it that way.

It's not like the stuff is $150 per bottle.

[Jim]

how are you diluting it if you push the old fluid out? so when you change fluids, you air out the entire system before adding the new stuff?

[eboos]

Do you think that the different fluids will not intermix?

When I change fluids, I empty the old stuff and start from scratch with the new stuff.

[Jim]

interesting. i'd like to hear what Degs has to say about this topic. maybe he'll chime in

[scubasteveRR]

yes i have a mitivac, but dont use it anymore. i've got a clear hose that i put on the bleeder, so i can see air pockets coming out.

since you're buying some stuff from Ted, pick up a pair of Goodridge speed bleeders.

I already have the speed bleeders on my list from Ted and I also have one of those clear tubes attached to a gatorade bottle that we use for bleeding brakes already.

[FireboltEric_MA]

Jim is an expert with brakes. Do what he tells you.

[keeena]

how are you diluting it if you push the old fluid out? so when you change fluids, you air out the entire system before adding the new stuff?

Do you think that the different fluids will not intermix?

When I change fluids, I empty the old stuff and start from scratch with the new stuff.

I'm with Eric on this one. Think of where the brake line is attached to the caliper: usually in the middle. And the Bleeder is on the top of the caliper. So when you're bleeding, fluid below the brake line attachment point will take a while to totally flush out. Granted, a bit picky, but makes sense to me.

[fjrrider RI]

I may be slightly off topic but want to know how long you can run the brake fulid and what happens when you run it for to long?

[DuncanMoto]

I may be slightly off topic but want to know how long you can run the brake fulid and what happens when you run it for to long?

Change it every 2 years, 5,000 miles or even more often, depending on use and temperature swings.
I do mine once every year on any bike that hits the track and every 2 years on bikes that are street only.

[Expat]

Playing devils advocate, what makes one fluid better than the other?
Has anyone had fluid boiling issues on a bike around here?
Repsol is a very reputable company, I doubt that even their cheapest DOT4 fluid is not up to the job!

[Jim]

Has anyone had fluid boiling issues on a bike around here?

yes, i have. but it was because the caliper piston seals were busted & causing the pistons to stay out, resulting in the pads dragging on the rotors & bioling the fluid