Brake fluid

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I'd like to flush and refill the brake fluid in our Blazers. I don't see where it discusses this in the Haynes manual. I have ordered the Chilton's manual but it won't arrive for about a week. Am I just skipping over it somehow in the Haynes manual?

GM recommends DOT 3 fluid. What particular fluid do you guys use in your trucks? Should I look for something better, perhaps MOTUL DOT 5.1 Brake fluid? Here is the link I found to the MOTUL (french company) brake fluid:
http://www.motorspot.com/motul.html

Thanks,
-- recurve

[quaddriver]

dot 5 (silicone based) brake fluid is not compatible with glycol based fluids. It is also not for ABS systems as it is abel to compress slightly.

flushing out a gm system is easy, put hose on each bleed screw and open them up and make sure you keep the resevoir topped off, it will slowly drain without ever touching the pedal.

If you introduce air however, it gets more complicated as you must use a rwal or 4wal compatible scan tool to cycle the pumps while bleeding.

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If I understand things correctly, Dot 5 is silicone based but Dot 5.1 is not because (as you said) silicone compresses slightly.

Here are the stated specs of the MOTUL Dot 5.1 brake fluid:

1) Non-Silicone - Long life
509 degrees dry and 365 degrees wet. Polyglycol based. Exceeds the highest DOT specs. For use in all systems that require a DOT 3, 4 or 5.1 fluid. Container is filled with nitrogen for inreased shelf life and to eliminate contamination

2) Long life. 100% synthetic fluid for hydraulic actuated brake and clutch systems.

3) Dot 5.1, non-silicone base. Fluidity is specially designed for anti-lock brake systems.

4) The viscosity (820 centipoises at -40°c / -40°F) is lower than DOT 4 and DOT 3 brake fluids, which allows Motul Brake Fluid Dot 5.1, an easier fluid circulation in micro-valves of anti-locking systems.

5) Neutral with seals used braking systems

6) Anti-corrosion formula

On paper, it sounds great but I wonder if it is as good as it claims. DOT 3 boils at 400 degrees when dry.

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The only way air would get in the system would be if the new brake fluid level in the master cylinder reservoir became empty, correct?

Ah, I found where the Haynes manual talks about bleeding the breaks. It is in Chapter nine but there is nothing about it in the "routine maintenance" chapter. I thought break fluid needed to be replaced every two years…

It's good to hear that the breaks can be bled slowly without having to pump the break pedal, but how long would that take (how slow is slow?)? I did a little bit of research and found a tool that looks promising. It's called "speedibleed" and costs $139 for their K200 kit that works with our Blazers. It uses the tire pressure from our wheels to bleed the brake system. Claims to be fast and safe. Here are two links I've found about it:

http://www.speedibleed.com/evolution/history.htm
http://autorepair.about.com/cs/produ...afpr051003.htm

Do you guys think this is money well spent or do you know of comparable (perhaps better) bleeder tools?

Thanks,
-- recurve

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Hey, what does everyone think about ATE brake fluid (German company). They make a DOT 4 fluid that exceeds most DOT 5.1 specs. Looks like it might be the best brake fluid for the money at about $10 / liter. Another neat thing about ATE fluid is that you can buy it with either a blue color or gold color. That way when you flush the system, it is braindead easy to tell when all the previous fluid is out of the system.

How much fluid does it take to flush the brakes on a Blazer (model years '95 and '97)? About a liter? I'm planning on buying three liters tomorrow for our two trucks, should be enough right?

Here are two nice links that describe different types of brake fluids:

http://www.stealth316.com/2-brakefluid.htm

http://www.vtr.org/maintain/brake-fluids.html

Here is the place I intend to purchase the ATE brake fluid from tomorrow (they don't have online ordering and aren't open now):
http://www.raceshopper.com/ate_brake_fluid.shtml

The blue stuff is "ATE Super blue" and the gold stuf is "ATE Typ 200." Supposed to be identical, just a different color.

Again, 3 liters of brake fluid should be plenty for flushing the brakes on two Blazers correct?

Thanks,
-- recurve

[recurve]

Today we changed the brake fluid in our '95 Blazer. It's not so bad. For a complete novice, it might take somewhere between 1 hour to 2 hours to do the job. You'll need two people though.

Using either the Haynes or the Chilton's manual, read what it says to do in the chapter dedicated to brakes.

I can add the following to what those manuals said:

For the rear bleeders, I needed an 8mm wrench.

For the front bleeders, I needed a 10mm wrench.

For the right rear bleeder, we needed to cycle the manual brake pumping technique over 20 times to get all the old fluid out of that line.

The left rear bleeder? about 15 times.

The right front and left front bleeders? about 10 times each.

Using the ATE super blue fluid was nice, as I could easily see when the new fluid came through.

I believe the manual said the brake lines utilized 1.1 liters of fluid; however, it appears that we only needed 0.75 liters (less than one liter) to do the job.

Cheers,
-- recurve