Master cylinder problem?

[crvc]

I ordered a new master cylinder from Cal Imports. I have a 1967 bug. They sent me a master cylinder for a later model with a dual circuit system. I installed it and have been unable to bleed the brakes. Today I grabbed my neighbor to pump the pedal as I released the bleed valves. The right rear pumped out a lot of air then fluid. I repeated the action on the left rear and got the same; air first then brake fluid. With each pedal
stroke there was a steady flow of brake fluid from each rear brake.

Then I bled the front brakes. There was some air coming from the right front but afterwards there was little flow. Compared to the rear, probably a quarter the volume of fluid being pumped through the front. But that's just 'eyeballing' it. I didn't try to measure.

Is that a clue? I can't find any fluid leakage anywhere. Also the level in the reservoir isn't dropping. But the pedal still drops to the floor unless I'm furiously pumping it. When pumping the front brakes I noticed the fluid coming from the slave cylinders seemed foamy.

TIA for any suggestions,

Kevin

[MNAirHead]

I've had some bum latin america parts lately.

[Bookwus]

Hiya Kevin,

I ordered a new master cylinder from Cal Imports. I have a 1967 bug. They sent me a master cylinder for a later model with a dual circuit system. I installed it ..........

Why would you knowingly install the wrong part?

[crvc]

I'd call it an upgrade. The 1967 master cylinder has only one piston that has to actuate all four wheels. The later models have two pistons, one for the front wheels and one for the rear. I didn't necessarily want it but it fits and should have a bit more stopping power. Especially if I ever decide to switch to disc brakes.

Kevin

[MNAirHead]

Hiya Kevin,

I ordered a new master cylinder from Cal Imports. I have a 1967 bug. They sent me a master cylinder for a later model with a dual circuit system. I installed it ..........

Why would you knowingly install the wrong part?

dual circuit brakes.. singles are dangerous when they fail.

[Marc]

...Why would you knowingly install the wrong part?

The `67 master cylinder is a legit dual-circuit piece (in any car sold in the US, anyway - dual-circuit was the law of the land here in `67) but it's been obsolete for some time. Like the `68/early`69 "three-switch" M/Cs, it used discrete residual pressure check valves at each of the three outlets...these also acted as thread adapters. The "universal replacement" for all `67-up Type I (except Super), 113 611 015BD, uses restriction drillings rather than RPVs so the pipes thread directly into the casting. It uses two stoplight switches like the OEM `67, so wiring modifications are needed to put it into a `68/early`69 if you want the brake system warning light to function. It also has the late large-diameter feed lines so you must use adapters to connect it to the small-outlet `67 reservoir.
ANYWHOO, this isn't a "wrong-part" problem - the 113 611 015BD is the only part available for a `67 and it should work just fine (with the aforementioned feedline diameter problem solved).

"Furious pumping" will indeed whip the fluid into an froth. Let it sit for a couple hours and try again, slow & deliberate.
How old are the flex hoses on this car? Even if they look OK on the outside, they can be constricted inside and inhibit flow.
Check that the pedal stop is adjusted to put the pedal ~8" off the floor, and that when the pedal is "up" you have ~¼" of free pedal movement before the pushrod contacts the M/C/ piston (1mm / .040" pushrod freeplay is recommended). If there's no freeplay the compensating ports won't be uncovered when the pedal is up and fluid can't flow in from the reservoir.

[crvc]

Thanks for the replies. The car is over 40 yrs old so I'm wondering if there could be problems in the front wheel cylinders. I ordered a pair of cheap rebuilt kits. While I'm waiting for them to arrive I'll measure the pedal stop and check for restrictions in the hoses.

Kevin

[MNAirHead]

I've had better success with quality complete cylls.. unfortunately I've had quality issues with the rebuild kits.

Tim

[crvc]

I understand it might not work but the kits were $6 each. If they don't work I'm only out $12. Last month I quit driving to work and I'm riding a bike instead. That's saving me a lot of gas money so I can afford the $12.

Kevin

[MNAirHead]

Understood.. complete cylls that are quality are about $22.

Tim

[Marc]

113 611 057 (`65-`77 Standard front wheel cylinder):
I can get German Ate for $20.71
TRW Brazil are $18.56
KMM Chinese are $6.70

cip1 sells Brazilian Varga for $11.35

At one time I was a staunch advocate of using only Ate or FAG brake hydraulic components (the two OEM suppliers to the VW factory). The next best alternative was the Mexican-made stuff like VW dealers sold as their "000" budget line - but the Mexican plant burnt down years ago.
In my experience (back in the `80s) the German & Mexican parts lasted longer and when they did go bad they seldom did so catastrophically, whereas the Brazilian parts (especially Varga) seemed more likely to go all-at-once with no warning. Over the last twenty years or so it seems to me that the Brazilian stuff has gotten better and the German worse, to the point that I now find it hard to justify paying a premium price for German.

Just last week I decided to try a KMM Chinese master cylinder out in my daily driver ...so far, so good, but I'll have to see it hold up for at least a year or two before I'll be comfortable selling KMM to the public.
Price comparison on 113 611 015BD at Marc's Outlet:
FTE (not Ate, but German) $130.24
TRW Brazil $37.39
KMM $20.40

cip1 sells Brax (another non-OEM German) for $59.95 and a "non-European" (brand not disclosed, but the photo on their site looks exactly like the KMM I just put in) for $39.95 - they refer to it as "good quality".

The surface finish and diameter of the bore probably have more to do with the success of installing a rebuild kit than the brand. I've found that as a rule by the time a VW cylinder needs rebuilding it's got too many rust pits for a reliable seal (and by the time you hone them out the diameter is too great). The residual pressure valves used on the early master cylinders kept a slight pressure in the line which helped keep the lips of the wheel cylinder seals in good contact with the bore - the restriction drillings used on the newer M/C's don't hold any residual pressure and wheel cylinder leakage is more common, no matter what you pay for the part.

[david58]

leakage is more common, no matter what you pay for the part.

I wish parts had the date of manufacture on them, you can buy a new part that is 30 years old, rubber will not hold up for 30 years sitting on a shelf. I glanced at my buddies tires on his 4x4 and couldn't believe they had dry rot cracks in them. He bought them like 6 months ago and they still look brand new except for the cracks.

[fastvwman]

I replaced my stocker with a cnc master. its a bolt up affair with the adaptor plate they sell. all I did was to add a barbed fitting to the top of the reservoir and run the from the stock reservoir line to it. I have never had better brakes and ill never run a varga p.o.s. again.

[gilbequick]

113 611 057 (`65-`77 Standard front wheel cylinder):
I can get German Ate for $20.71
TRW Brazil are $18.56
KMM Chinese are $6.70

cip1 sells Brazilian Varga for $11.35

FTE (not Ate, but German) $130.24
TRW Brazil $37.39
KMM $20.40

I don't care what the price difference is, I WILL NOT buy Chinese anything if I can at all help it. We're screwing our country (USA) and it's people everytime we buy more of their cheap crap and support their sweat shops. I've bought to many Chinese things in the past and have regretted it 90% of the time when the POS failed/broke/fell apart/wore out/you name it and I've had to replace it with a quality part later on.

It's just not worth it to have to pay twice and do the labor twice.

[fastvwman]

I don't care what the price difference is, I WILL NOT buy Chinese anything if I can at all help it.......... It's just not worth it to have to pay twice and do the labor twice.

so use the cnc master "made in usa" and it works.