29 Series 65 Brake Issues

[Narve N]

The Ser 65 that had starting issues back in May, now runs - er - fairly well. However a new issue has appeared; that the pressure in my brake system has disappeared.
No resistanse is felt in the system after I replaced the brakelight switch last week (with one from H-D, apparently capable of handling silicon fluid). The system otherwise compose of old components with new rubber internals after a hefty dose of polishing the bores, and did initially work quite good. Anyone got an idea why the pressure is gone? (I did bleed the brakes after the pressure switch change and still use mineral fluid)
The main supect is the master cylinder and I do have a second MC with re-sleeved bore. This however was seeping brake fluid from the treaded joint between the two main MC parts when I tried it, something that has never happened with the non re-sleeved one. Is this a common issue, and can I use any type of sealant on the treads to stop the leak?

[keiser31]

Did you do the brake adjustment prior to the brake bleeding?

[Narve N]

Brakes were adjusted prior to bleeding, with a make-do method of yardstick before putting the drum on and then the external ones once more.
Will try to see if I can seal the rebored MC today with silicon-based fluid gasket sealant.

[Dave Fields]

I have not hd this issue with my 29 65. Let us know how you make out.

[Narve N]

I finally made the brakes work after bleeding two quarts of fluid through the system. They are however not as assertive as expected and I still suspect there to be some air in the rear axle brake tube where the high point is above the altitude of the RR wheel cylinder. Another issue could be a possible leak through the bleeding screw on one wheel, letting in small amounts of air when releasing the pedal, even if the screw is meticously closed for every pump of the brakes.

[keiser31]

One thing I learned is that the bleeder screws and seats MUST seal. Any small leak will screw up the bleeding process. As I posted elsewhere, here is a simple tool for adjusting the shoes. Start with the lower cams and go to the uppers next. If the shoes rub just enough to hear them touch, you are golden. Another hint in case you were not aware...start the bleeding process at the furthest wheel cylinder from the master cylinder and work your way to the nearest.

[ch1929]

When I got my wheel clyinders back from being resleeved, we had to recut the bleeder seats for a perfect seal with the bleeder screws. They were way out of shape after the resleeve process.

Roland
1929 Model 65 Sedan