master cylinder problem?

What year is your master cyl?

It changed in 67. There are both single and dual chamber masters.

T.

It's a 74 VW. I was thinking that perhaps either I'm leaking in the rear brake system or the rear chamber of my master cylinder is shot somehow. Thanks again.

I've been plagued lately with poorly built components... German, Italian and Brazillian... funny thing the South American stuff has been performing better.

Warm Regards.

I feel your pain. I just replaced a Bosch rebuilt Generator with no miles on it. I installed it, drove it down the street and heard a noise from the back of the car that sounded like the fan belt snapped. The red light came on so I pulled over and checked it out. Fan belt was in tact but a little red wire inside the gennie was all frayed and burnt looking. Drove home and the thing was putting out 2 volts. What a pita.

--Dan E

Yes a 74 has a tandem master cylinder. If the rear brakes failed also, then that is a separate problem.

Don't adjust the pushrod. That's an adjustment made only at the factory to assure sufficient pedal travel if half the tandem system fails.

Not sure I understand the question, but...

If you're asking about a pedal that doesn't come all the way back up when released, then look at the return spring to see if it's broken, or the pedal shaft to see if it's rusted, or at the pedal stop plate to see if it's misadjusted or there's dirt in there.

Make sure there is a tiny bit of free play in the pedal at the top of its travel. If not, adjust the pedal stop plate to make it right.

If you're asking about a pedal that goes "too low" when pressed down, then that's either an indication of air in the system, a leaking (possibly internally) master cylinder, or of brake shoes that need to be adjusted.

----------------------------------------------- Jim Adney snipped-for-privacy@vwtype3.org Madison, WI 53711 USA

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That's assuming you have the orginal cluster or that the og has never been removed or that the stop hasn't shifted after 30 odd years, all highly unlikely. The BBB gives the amount of the gap necessary and you can easily adjust it if necessary.

--Dan E

The original cluster is usually there, but I agree that it could have been exchanged.

If the stop has shifted, or been adjusted, that's no problem, because that's the part that you're SUPPOSED to adjust, rather than the pushrod.

What is og?

Assuming BBB refers to a manual, then that same manual will also explain that you should adjust the stop plate, not the pushrod, to set the brake pedal free play.

----------------------------------------------- Jim Adney snipped-for-privacy@vwtype3.org Madison, WI 53711 USA

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clearence between the pushrod and the MC, right? So, why shold it matter if you adjust the pushrod to determine the clearence?

Or, more accurately, Original German.

Now, turn your hat back around.

;-)

I guess I'm the one being didactic here. You're right, they both affect the free play, but changing the pushrod length can (if you shorten it) leave you with insufficient pedal travel (pedal hits the firewall) if one of the tandem circuits fails.

While the nominal pushrod length is given in all the manuals, they are also careful to tell you not to change it unless the original length has been lost. The original length was set at the factory using a special gauge. VW did it this way because the MC attaches to the pan, but the firewall is part of the body. Tolerance buildup between all the related parts meant that there was no other way to maintain the necessary clearances.

In spite of the warning in ALL the manuals not to adjust the pushrod length, this is still something that is widely misunderstood.