C60 cwt Signals CZMk IV

[Phil Waterman]

Hi Gordon

If you have not already read Tony's thread you might want to take a look at the posts dealing with the booster. Speaks to replacement boots.

When I bench tested my units what I was particularly looking for was leak down of the vacuum. Primary leak problem areas are the little seat for the control rod and the seal were the vacuum chamber seals to the housing.

Doing anything with this little rod has to be done carefully.(I'm looking for the manual pages on the booster to post on line.)

To get the inline check value out of the picture as a leak source use a good ball valve so you can pull the vacuum on the unit and then turn of the valve and see how long it takes for the vacuum to start dropping. When everything is perfect it will hold the vacuum over night.

When you reassemble the big piston with the leather gasket be sure to soak the seal in oil. The manual also includes adding oil to the cylinder on a regular basis. They are correct about it needing oil added with mine I include putting several ounces in each spring when I do my preseason brake check.

Another point is to use a stiff oil resistant hose to connect the booster to the manifold. Heater hose will work at first but gets soft and will actually get sucked flat. Auto air conditioning flex hose seems to work well. (10+years) It is also easy to get, either new or used.

Cheers Phil