brake servo push rod setting

[elvimto]

I have my servo apart and I also picked up a spare a while back. The Lockheed sevice book says the push rod setting should be .125 for a tandem master cylinder, thats the distance the rod sticks out past the top of the servo or vacuum shell. When I removed mine from the car it was not at that setting. I used the spare servo push rod and made the adjustment its now at the lowest setting with no more adjustment left and it is still a little higher than it should be but it is shorter than the one that came out. I have no reason to believe that the servo that came with the car has been changed or that the push rod has been adjusted, (no tooling marks on the stem) For now I am going to go with the smallest setting I can get on the servo push rod which is about .075 thou above spec and see if i can get my brake system working with servo assist anyone have any comments or have been up this road before?

The reason for the change is my brakes started playing up and it was the concensus that the diaphragm was shot.

cheers Stuart

[martin]

Hi Stuart, the push rod length only affects the pedal travel, too short and travel is increased, I'd go for the longest you can get without the rod permanently operating. The quoted length in the manual, is basically to allow for semi-skilled fitters in the factory or dealerships. No insult intended, but they were dealing with large numbers and little time. Martin.

[elvimto]

Thanks for the reply Martin, I put the assembly together and road tested it just over an hour ago at least I have a good braking system with slightly longer pedal travel as you say. It turns out the push rod lenght as found was 3.535 inches and the shortest I could get the spare rod was 3.160 inches so you have .375 difference. I am just happy to have the brakes back to function as they should with the vacuum booster. On a side note with the engine sitting at tick over the vacuum is 18 inches solid so i have no leaks in the system. I will swap out the rod maybe tomorrow. Also found that my brake lights don"t work now and turn signal on one side, still happy to save 160 bucks on the servo repair kit.

cheers Stuart

[Westfaling]

Stuart
You may have bent the bracket that holds the brake light switch so that it no longer contacts the brake pedal arm.. It's easy to apply the brake and bend the bracket back. I can't help with the indicator.
Nick

[elvimto]

Went back out to the garage and found the problem so on Sunday i am going to clean all the bulb holders and replace some of the bulbs, checked the switch for the brake pedal it worked seems that most of my problems are dirty ground connections to the holders, that was a three beer fix tonight.

cheers Stuart

[martin]

Went back out to the garage and found the problem so on Sunday i am going to clean all the bulb holders and replace some of the bulbs, checked the switch for the brake pedal it worked seems that most of my problems are dirty ground connections to the holders, that was a three beer fix tonight.

cheers Stuart

Good news mate, but only three ? Martin.