Brake Fluid Replacement... why?

[ForbesMarch]

can someone please explain to me WHY must I replace my brake fluid if the brakes are working fine as part of the routine maintenance?
Also, is the $60 for the brake fluid resevoir pressurizer worth the money? It seems like alot for a seemingly unnecessary procedure.

p.s. absolutely love this board. Makin' me fall in love with "the old tank" all over again.

[JRL]

can someone please explain to me WHY must I replace my brake fluid if the brakes are working fine as part of the routine maintenance?
Also, is the $60 for the brake fluid resevoir pressurizer worth the money? It seems like alot for a seemingly unnecessary procedure.

p.s. absolutely love this board. Makin' me fall in love with "the old tank" all over again.

Making the answer simple, brake fluid degrades over a couple of years, four years and it's JUNK

[ForbesMarch]

Thanks, a speedy reply and that makes sense.
but, is the replacement in anticipation of it turnung to junk, 'cause if it turned to junk, I should feel it, right? I mean my brakes are working fine, there's no "spungy" feel, the way they feel if air gets in...

[Aviator]

http://www.type2.com/library/brakes/brakef.htm

This will answer your question. Don't play games with recommended preventative maintenance......especially when it comes to brakes and ABS !!!!

Dave.

[gibbons]

When I flushed mine at 60K miles, it was a brownish color indicating rusting in the system from absorbed moisture. It was nice to see nice, clean, clear brake fluid coming out of the caliper.

I used to try to use a vacuum type system, but found that it doesn't draw fast enough to suck out any air bubbles that may be hiding at high points in the lines. When I converted my Chevelle's brakes from drums to discs, they were really mushy after multipe vacuum bleeding attempts. I finally bought a canister pressure bleeder, the $60ish kind, and blew the fluid through quickly and in high volumes. I got a bunch of bubbles out, and the brake pedal firmed up nicely.

I used the pressure canister on the XC, using a Euro car 40mm adapter. Worked like a charm and I didn't spill a drop.

[MoeB]

...but, is the replacement in anticipation of it turnung to junk, 'cause if it turned to junk, I should feel it, right? I mean my brakes are working fine, there's no "spungy" feel, the way they feel if air gets in...

It's preventive maintenance of the brake system. If one of your brake lines ruptures due to corrosion, yes, you will feel it. If it happens when you're going 50mph and you need to stop before plowing into somebody else, grab the emergency brake and hope it hasn't been neglected, too.:eek:

[PierreC]

can someone please explain to me WHY must I replace my brake fluid if the brakes are working fine as part of the routine maintenance?
Also, is the $60 for the brake fluid resevoir pressurizer worth the money? It seems like alot for a seemingly unnecessary procedure.

p.s. absolutely love this board. Makin' me fall in love with "the old tank" all over again.

Main reason is that brake fluid is hygroscopic, i.e. it absorbs moisture over time. This lowers the boiling point of the brake fluid and can in extreme circumstances lead to break failure

The other - IMHO more important - reason is that the moisture will cause rust in the master and/or wheel cylinders or callipers, which are EXPENSIVE to repair on top of the fact that the rust can / may destroy the rubber seals, which can lead to brake fluid loss [sometime suddenly] and therefore reduced or even loss of braking capability ...

Hence the recommendation to replace brake fluid every two years or every year in very humid climates OR when the brakes are subject to extreme usage such as mountainous or dusty regions.

[Willy]

Braking fluid is indeed hygroscopic, the fact that it absorbs moisture is a very good thing, this prevents moisture from sinking to the lowest point, the brakes! If this would happen, the fluid could vaporize when the brakes are used heavily (vapor lock).
Since brake fluid is very agressive (eg strips paint) I believe it should not be flushed as preventive maintenance but because it is necessary to do so.
The boiling point can be measured, a tool is affordable for a dealer, only if the boiling point becomes too low should the fluid be replaced.
As it is not a problem to measure the condition of brake fluid, I believe the "normal" procedure of replacing brake fluid is mostly an economic approach, not a technical one, more so since the degradation of the fluid is connected to driving style.
Wily

[knucklebuster]

New brake fluid should be almost clear like vegetable oil. Over time, it turns dark and over many years will thicken like jelly. Complete flush every couple of years is my suggestion. It's a simple job, keeps moisture out, and prevents bleeders from siezing. ALL fluids should be periodically renewed, regardless of what Volvo tells you. Sorry but I do NOT see any connection with driving style.

(if brake fluid thickens, calipers etc have to be dismantled to clean it out. I had to do this to a motorcycle once)

[ForbesMarch]

ok, I'll do it!
Does anyone know how much brake fluid it will take to flush the system? Can you use any DOT4 or do you have to use the Volvo stuff?

[Forkster]

And where can we get a pressurized bleeder for $60? :)

[Omega5]

Forbes: DOT3 and DOT4 are NOT COMPATIBLE! Make sure you flush with the correct one. You can go from DOT2 to DOT3 as an "upgrade" but NEVER from DOT3 to DOT4 or vice versa.

[PierreC]

Forbes: DOT3 and DOT4 are NOT COMPATIBLE! Make sure you flush with the correct one. You can go from DOT2 to DOT3 as an "upgrade" but NEVER from DOT3 to DOT4 or vice versa.

I don't have the book with me, so I can't say for sure, but I BELIEVE MY04 XC70 has DOT3 fluid in it.

Wrong! It is DOT4 ...

[ForbesMarch]

And where can we get a pressurized bleeder for $60? :)

You can get one at iPd.com.
http://www.ipdusa.com/Volvo-V70XC70-2001-2007/Brakes/Motive-Brake-Bleeder/p-127-376-437/
That's the link.

What does a bleed cost at the dealer (anything close to what it would cost myself and I'll do it myself...)