Re: Vacuum Advance unit

Posted by JWL On 2009/10/26 10:14:35

One can check the mechanical or automatic advance without a distributor testing machine with the distributor in the car. It is a tedious job but with the vacuum advance disconnected and line plugged, check the amount of advance on the vibration damper timing marks at different engine speeds (500, 1,000, 1,500, etc). Note the amount of advance at each speed and compare it to the specifications. It is probably okay.

I believe the main difference in the same type of vacuum advance units is the spring and shims (if any) in the units. You may be able to use a unit from another distributor (same manufacturer) by using your spring and shims (if any).

I have used a light machine oil for lubricating the breaker plate with good results. A little goes a long way. Lubricate the felt pad under the rotor with a couple of drops of this oil too. Some light grease like Lubriplate on the cam lobe is recommended. Again, just a small amount spread on the lobes.

Clean the distributor thoroughly while you have it out of the car. It is a cinch to install new points and condenser at this time too.

Let us know how you come out on this job, and good luck.