"Must use a power brake bleeder"

[schwim]

Hi there everyone,

This is a 59 with all stock system aside from a dual circuit MC.

I reassembled my ride after a decade of dismantlement and the brakes have been problematic. Although I'm not losing fluid level, after bleeding the brakes, the pedal goes from very little braking to no braking at all with the pedal reaching the metal. Since all the parts have lived a decade of being dry, I figure that I need to replace the cylinders regardless but I'm curious about all the parts sites stating that you must use a power bleeder for this system. I do have a power bleeder but it's not solved my current issue and I've owned various vws over the decades and never used a power bleeder on them so I'm curious:

1) First, why does every parts site state this? What's particular about this system that they feel it's necessary(or highly recommended) or are they just trying to stop support requests from people that aren't adept at bleeding brake systems?

2) What's the preferred bleeding method? My power system attaches to the WC and draws the fluid through using suction. I've just been rotating through the WCs from farthest to closest the MC.

3) If you're unable to get a usable brake pedal but you're not losing fluid, is that most likely indicative of a bad plunger(s) in the MC or something else?

Thanks for your time!
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Zippy the Wonderbug's achingly slow meandering toward roadworthiness

[rcooled]

After sitting for 10yrs, all the seals are probably shot. Replace the master cylinder and all the wheel cylinders, flush with fresh fluid, then try bleeding the system again.

Have bled VW brakes many, many times, both single & dual circuit, and never used a power bleeder. Your reason #1 for the vendor's statement might be closest to the truth.
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'63 Ragtop (current)
'65 Ghia coupe (totaled)
'67 Ghia convertible (current)
'69.5 Ghia convertible and
'62, '63, '65, '69 Bugs (all long gone)

[EVfun]

I've never used a power bleeder and I've never pre-bled a master cylinder either. If I have a problem getting good brakes it's usually either a bad master cylinder or a bad flex hose. I've had brand new master cylinders be bad, but never a new flex hose. Frozen wheel cylinders can also be a problem that doesn't leak, but that is often more noticed when you go for a test drive (brake drag beyond a slight touch).
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[Bobs67vwagen]

As above posters have stated 10 years is too long for this stuff to sit around dry. Replace all of it and the rubber flex hoses front and rear. I have never used a power bleeder on a VW in over 50 years. I have found that the process is easier when the master is bench bled before installing. I use a mitey vac hand held pistol grip vacuum bleeder on all my cars and it works well, but I'm sure your power bleeder will work well on new functional parts. Try to get quality wheel cylinders and master. I have found the European built units to be the best. Since the dual circuit update was done, review the manual and samba info on pedal freeplay, stop bracket adjustment and pushrod length. This is important to get the benefit of the dual circuit system in the event of failure of one master cylinder port. Good luck Bob

[zerotofifty]

in fifty years of servicing my and others Bug brakes, never used a power bleeder, i.e. not needed.

if the seals are compromised, then a leak may occur, if no leak then the seals are assumed good I have used cylinders many decades old that sat dry. of course seals do eventually degrade, cylinders can rust, but you usually see leaks when that is bad.

if pumping the pedal causes the pedal to come up from htting the firewall, then that usually means you got air in the system still.

it maybe the valve in the master is not sealing, that can cause the symptom you have. In which case rebuild or replace the mater. the wheel cylinders do NOT have a valve, if they aint leakkng, they are not the problem

so if pumping pedal does not bring the pedal up from fire wall, I assume the master internal valving is leaking internally you wont see spilled fluid with an internal leak from a bad valve.

good luck
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Sorry About That Chief.

Give Peace a Chance.

Words to live by.

[scrivyscriv]

From my experience with brakes sitting dry, you will save a lot of time just replacing the master and wheel cylinders now if you're ready to drive the car.

There are some vehicles that are engineered in such a way that the brake or clutch master cylinder is pointed slightly nose up in its installed position. Air bubbles in the master can be difficult or impossible to get out in that scenario. The early Ford Explorers had a clutch master like that IIRC.

Bugs don't have that problem because they are not mounted on an angle. If all one did was pump bleed a bug brake system, eventually it would be fully bled. There are a lot of clearances in the drum brake system that make bugs kind of a pain to bleed but it's not really difficult once you get the hang of it.

I personally like pressure bleeders because it's a one-man show and you don't have to adjust all the brakes full tight during bleeding, so there's less overall work and it tends to be quicker. You can make one pretty cheaply... cost isn't a prohibiting factor here.


This is my cap setup, with a pump up garden sprayer.

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Robert in Memphis
Dünkelgrügen 1967 Java Green bug thread
Engine rebuild thread
If you're ever in the Memphis area, you are welcome to stop by for advice and help.

[EVfun]

I have never used residual pressure valves with the VW dual circuit master cylinder. I’ve never found it needed, and VW didn’t include them after sometime around 1970.
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[Eric&Barb]

Being on East coast you have lots of humidity, that will rust up all the brake cylinders. Replace everything in the brake system. Would at this point even replace the brake hard lines with one of the new rust proof sets. Then use DOT5 brake fluid (not DOT5.1) so you can get 8 or so years instead of 18 to 24 months between needing to tear the brake system apart due to rust in the cylinders. DOT3 brake fluid sucks water right out of the air.
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In Stereo, Where Available!

[scrivyscriv]

[Bobs67vwagen]

Just to expand upon what occurs when VW brake sit unused for a long period. My 67 bug has sat unused in one of my garages for 10 years while I attended to aging parents in Florida. When I put it away I did not touch the brake pedal when I rolled it into the garage and did not set the the parking brake. I went to move it to another garage today to start a resurrection and both front brakes were locked solid. I hammered and lubricated the heck out of them, pulled the pins that secure the shoes out of the backing plates and it was still difficult to get the drums off. I live in a humid climate and this is what happens.

[viiking]

I'm an old fart too like some of the other posters here. I have in 50 years also never had to resort to anything other than the VW method of bleeding the brakes even though it is getting harder to lie on my back under the car.

I post on here regularly about brake issues and my advice is that whatever replacement part you buy you need to understand how the MC works. Many of these are copies of what design? Do they need residual pressure valves? Do they have internal drillings? What is the correct bleeding method? Rears first? Fronts first? Yes it makes a difference.

My preference is to pay the big money and buy OEM parts like ATE or FTE if I can get them. At least then you might have a better chance to get it right.

I always find it bizarre that people spend lots of money on shiny and go fast bits then cheap out on the most important part of a car. The brake system.
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1968 1500 RHD Lotus White Beetle since birth. In the hospital for major surgery
1966 Lancia Flavia Pininfarina Coupe - in the waiting room
Discharged: 1983 Vanagon, 1974 1800 Microbus,1968 Low Light,1968 Type 3

[schwim]

[viiking]

[Bobs67vwagen]

Hey shwim that thread that Viking gave you has all the info on how to get the brake pedal and pushrod set up and on the bleeding sequence. He and baldessarian know their stuff when it comes to brakes. I hope it helps you solve this.