Brake Fluid Flush, How Often?

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wcfvw69
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Brake Fluid Flush, How Often?

Post by wcfvw69 » Thu Sep 24, 2015 1:34 pm

I'm just curious as to how frequently folks change and flush out their brake fluid in their classic VW's? I've read different time frames but we know brake fluid can absorb moisture from the air. Searching the internet, it states anywhere from 2-3 years, brake fluid should be changed.

I just flushed my fluid in my 67 bug. I realized it had been "gulp" 7 years. It looked like dark, used oil coming out through the clear plastic hose on the bleeder nipple.. I hope I didn't rust and pit my wheel and master cylinders..
1970 Westfalia bus. Stock 1776 dual port type 1 engine. Restored German Solex 34-3. Restored 205Q distributor, restored to factory appearance engine.

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Amskeptic
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Re: Brake Fluid Flush, How Often?

Post by Amskeptic » Fri Sep 25, 2015 7:23 am

wcfvw69 wrote:I'm just curious as to how frequently folks change and flush out their brake fluid in their classic VW's? I've read different time frames but we know brake fluid can absorb moisture from the air. Searching the internet, it states anywhere from 2-3 years, brake fluid should be changed.

I just flushed my fluid in my 67 bug. I realized it had been "gulp" 7 years. It looked like dark, used oil coming out through the clear plastic hose on the bleeder nipple.. I hope I didn't rust and pit my wheel and master cylinders..
I never did flush the brake fluid out of the Road Warrior . . . . fluid darkens as the rubber cups wear. If the fluid or reservoir has a brownish cast, it could be rust developing.

If we apply the Marketing Force test on our brake fluid, I wonder if flushing is as dire of a need as they say . . .
Chloe, 65,000 miles since I have owned it, no flush. BobD, flushed at 32,000 miles, not since.
Squareback? Lexus? Lincoln? Mercedes? Never.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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asiab3
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Re: Brake Fluid Flush, How Often?

Post by asiab3 » Fri Sep 25, 2015 9:03 am

Amskeptic wrote:Lincoln? Never.
:cyclopsani:

That's good enough for me!
Robbie
1969 bus, "Buddy."
145k miles with me.
322k miles on Earth.

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wcfvw69
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Re: Brake Fluid Flush, How Often?

Post by wcfvw69 » Fri Sep 25, 2015 11:12 am

Amskeptic wrote: I never did flush the brake fluid out of the Road Warrior . . . . fluid darkens as the rubber cups wear. If the fluid or reservoir has a brownish cast, it could be rust developing.

Chloe, 65,000 miles since I have owned it, no flush. BobD, flushed at 32,000 miles, not since.
Squareback? Lexus? Lincoln? Mercedes? Never.
Colin
OMG! You LAZY BASTARD! :)

I'm actually surprised you don't flush your brake fluids Colin. I would of bet $100 bucks that with the obsessive maintenance you do on your bus's, that this step would of been on that list.

IDK, Over the decades, I've certainly seen enough frozen/rusted/pitted calipers and their pistons inside along with rusted and pitted wheel cylinders and master cylinders that I think it's worth it to do every 2-3 years (when I remember). From start to finish using a hand pump power bleeder and sucking the majority out of the reservoir w/a turkey baster, I had 30 minutes of time to flush it. Maybe $2 bucks worth of brake fluid. Does it guarantee rust prevention? Probably not but if it helps at all and extends the life of the brake cylinders, it's worth it to me..

BTW Colin, PLS answer you're PM'S Mister! :)
1970 Westfalia bus. Stock 1776 dual port type 1 engine. Restored German Solex 34-3. Restored 205Q distributor, restored to factory appearance engine.

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SlowLane
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Re: Brake Fluid Flush, How Often?

Post by SlowLane » Fri Sep 25, 2015 12:00 pm

It's my understanding that the primary reason to regularly replace brake fluid is to ensure that the boiling point of the fluid isn't overly compromised by the amount of water absorbed by the fluid.

Brake fluid likes water. It absorbs it readily. Even though it's a sealed system, water gets in there. Boiling point of fresh, unsullied DOT 4 fluid is 450 F. Boiling point of water is 212 F. The more water in the fluid, the lower the actual boiling point. The amount of water that gets into a system at rest over a given period of time is likely dependent on the local environment.

I've heard too many horror stories of motor-home owners taking their toys out of storage in the spring without performing any maintenance, then embarking on a road trip, only to find their brakes literally evaporating on them on the first serious mountain pass downhill. Assuming they survive, it kinda puts a damper on the trip.

Personally, I flushed my fluid before I drove the van down to California in 2011. I didn't bother for my recent trip back to Canada this summer, though in hindsight, I probably should have.
'81 Canadian Westfalia (2.0L, manual), now Californiated

"They say a little knowledge is a dangerous thing, but it is not one half so bad as a lot of ignorance."
- Terry Pratchett

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Re: Brake Fluid Flush, How Often?

Post by Amskeptic » Sat Sep 26, 2015 7:05 am

wcfvw69 wrote:
Amskeptic wrote: I never did flush the brake fluid out of the Road Warrior . . . . fluid darkens as the rubber cups wear. If the fluid or reservoir has a brownish cast, it could be rust developing.

Chloe, 65,000 miles since I have owned it, no flush. BobD, flushed at 32,000 miles, not since.
Squareback? Lexus? Lincoln? Mercedes? Never.
Colin
OMG! You LAZY BASTARD! :)
I KNOW, right?
There is science behind my pained refusal to screw with well-enough . . . :blackeye:

Turns out that a fresh charge of brake fluid can cause leaks and trouble as often as not. Abrasive sediment gets stirred up, cups will develop new leaks, and I decided that my obsessive observational behavior is acceptable as far as finding weepy wheel or master cylinders in plenty of time to hone them and re-use the old cups. Then I "flush the system" with a couple of ounces of reservoir top-off.

Strangely enough, I have never had a terrible leak or failure or boil-off of brake fluid on a treacherous downhill. BobD's rear wheel cylinders were honed in a parking lot the day before Thanksgiving, 2010. They are fine. Chloe's master cylinder was "rebuilt" the day before Obama's re-election victory, and is behaving fine even through this summer's taxing mountain driving.
wcfvw69 wrote: I'm actually surprised you don't flush your brake fluids Colin. I would of bet $100 bucks that with the obsessive maintenance you do on your bus's, that this step would of been on that list.

IDK, Over the decades, I've certainly seen enough frozen/rusted/pitted calipers and their pistons inside along with rusted and pitted wheel cylinders and master cylinders that I think it's worth it to do every 2-3 years.
I am surprised, too. But I have to defer to experience here. I also never change my plugs, condensor, rotor, distributor cap, wheel bearing seals, and have never turned a brake drum or a disk or a flywheel in my life.

I see rusted brake parts on customer's cars too. I wonder where the water gets in. Why are my cars behaving. Chloe and the BobD, I get. I drive them. I heat up the brakes good. But the Lincoln?
Colin
(I need to have a focused dialogue with you re: Pierburg double-diaphragm pumps. We'll get there when I am not driving all over the country with my sub-standard water-logged brakes)
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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wcfvw69
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Re: Brake Fluid Flush, How Often?

Post by wcfvw69 » Sat Sep 26, 2015 11:18 am

Amskeptic wrote: (I need to have a focused dialogue with you re: Pierburg double-diaphragm pumps. We'll get there when I am not driving all over the country with my sub-standard water-logged brakes)
I just hope your sub-standard, water-logged brakes don't cause your imminent demise before said conversation takes place. Occasionally, it has to be about me, right? :newb:
1970 Westfalia bus. Stock 1776 dual port type 1 engine. Restored German Solex 34-3. Restored 205Q distributor, restored to factory appearance engine.

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Re: Brake Fluid Flush, How Often?

Post by Amskeptic » Sat Sep 26, 2015 4:23 pm

wcfvw69 wrote:
Amskeptic wrote: (I need to have a focused dialogue with you re: Pierburg double-diaphragm pumps. We'll get there when I am not driving all over the country with my sub-standard water-logged brakes)
I just hope your sub-standard, water-logged brakes don't cause your imminent demise before said conversation takes place. Occasionally, it has to be about me, right? :newb:
It is always about You, my esteeeeemed customerrrrr.

Before people puke in their CoCo Puffs™, please understand that I experiment with my own cars far more readily than I ever would with yours.
I test my brakes, steering, and chassis comportment before taking to the road after doing work (and before driving the Lincoln/Mercedes/Squareback onto the road).
I do follow accepted brake maintenance practices with you all.

Say, how's the bus stopping?
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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wcfvw69
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Re: Brake Fluid Flush, How Often?

Post by wcfvw69 » Sat Sep 26, 2015 5:05 pm

Amskeptic wrote:

Say, how's the bus stopping?

Colin
The buses brakes you ask? Well, I haven't spent much time driving it as I've been diligently knocking thru a "to-do" list from a recent visitor-

* Figure out broken 1/2" breaker bar manufacturer, contact and return broken tool for a life time replacement. Done
* Reposition the wiper blades on two bugs so they rest in the correct position. Done
* Repair throttle positioner on 69 Vert, disassemble carb and blow out passages and jets for better adjustment response. Done

* Re-bleed and readjust brakes on Vert as I still don't like the pedal firmness since installing new, German master from WW. Only a couple of bubbles out of RR wheel. Pad adjustment was good. Still not 100% happy with pedal firmness.
* Remove buses engine door support rod, clean and lube frozen rollers and reinstall the correct way. Done
* Adjust worms on both bugs steering gears. Done
* Replace the two non-Pierburg fuel pumps w/a rebuilt one and a mainly, NOS one. Both square tops.

I still have on your list to start attacking and treating the slight surface rust under the bus and then undercoat it. I'm just deciding how anal I want to get w/it. The 67 bug has some rust under the battery on the original pan. It was the only rust on the bug and I decided to try to see what would work in removing it vs. simply scrapping the loose stuff off and then converting and painting over it. What I did was- removed the loose stuff with a wire wheel on a drill. Vacuumed it up. I tried a couple of rust removers. What worked best? Naval jelly. I found that I had to apply it, let it sit on the rust for an hour and then it removed some of it. Wipe it off, apply another coat and repeat. After about 8 applications and scrubbings, all the rust was gone, leaving some rust pits (no holes and nothing too deep) behind in the now shinny metal pan. I then used a rust convertor followed by a couple of coats of good paint.

It was an interesting experiment to see what would work in removing the rust and what wouldn't. I'd of loved to media blast it but being inside the car, that wasn't an option. I may consider that under the bus.. Who knows..

PS, you REALLY don't want to know what Eva brought home and cooked for dinner last night.. I promise you, you don't.. The only hint I'll provide is OMG...
1970 Westfalia bus. Stock 1776 dual port type 1 engine. Restored German Solex 34-3. Restored 205Q distributor, restored to factory appearance engine.

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Re: Brake Fluid Flush, How Often?

Post by Amskeptic » Sun Sep 27, 2015 9:51 am

wcfvw69 wrote:
Amskeptic wrote:

Say, how's the bus stopping?

Colin
The buses brakes you ask? The only hint I'll provide is OMG...
So they're good.
Colin :cyclopsani:

(brake forum, this is the brake forum)

(p.s. I replaced the rear shoes on Chloe when I installed the German drums. The pedal feels dramatically different. Shoes have different "compressibility" and give the pedal either a hard feel or a nice modulation.
I now have a lot of nice modulation. I thought it was a lousy brake adjustment, but upon closer look, the pedal was hitting up high like I expected, but giving me an inch of movement under progressive pressure. This is normal and even desirable)
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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wcfvw69
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Re: Brake Fluid Flush, How Often?

Post by wcfvw69 » Sun Sep 27, 2015 5:51 pm

Amskeptic wrote: (p.s. I replaced the rear shoes on Chloe when I installed the German drums. The pedal feels dramatically different. Shoes have different "compressibility" and give the pedal either a hard feel or a nice modulation.
I now have a lot of nice modulation. I thought it was a lousy brake adjustment, but upon closer look, the pedal was hitting up high like I expected, but giving me an inch of movement under progressive pressure. This is normal and even desirable
Interesting. The bolded part is about how the brakes feel in the vert. Interesting as when I changed the master cylinder, I also changed the rear wheel cylinders that leaked and the rear brake pads. I got the rear brake pads from WW. I wonder if that's where you got your brake pads?

The pedals high and not squishy. It just isn't as firm as the 67's. The car stops on a dime, so I'll just go with it..
1970 Westfalia bus. Stock 1776 dual port type 1 engine. Restored German Solex 34-3. Restored 205Q distributor, restored to factory appearance engine.

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Re: Brake Fluid Flush, How Often?

Post by Amskeptic » Mon Sep 28, 2015 5:22 am

wcfvw69 wrote:Interesting as when I changed the master cylinder, I also changed the rear wheel cylinders that leaked and the rear brake shoes. I got the rear brake shoes from WW. I wonder if that's where you got your brake shoes?

The pedal is high and not squishy. It just isn't as firm as the 67's. The car stops on a dime, so I'll just go with it..
I did get my drum brake shoes from Wolfsburg West. They might be pretty good quality. The cheapos I got for Chloe's front drums have stress fractures in the lining and no modulability, but they also have 73,000 miles on them now.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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