Incorrect 1971 240z Brake Push Rod length (not adjustment)

[Zed Head]

Good stuff here.  Worst case you find out that the disc was already there and it falls out.  People have made their own from thick pieces of rubber though.  

You can get more flex by unbolting the distribution block down below, for the left and right discs, I think.  I've done the same in the past.

On the other hand you could put it back together and see how it behaves.  From what I've read you'll know immediately if it's gone.  Then you can go through the ordeal.

[DaveR]

Most of the comments I have read seem to state that if the pushrod is improperly adjusted you will have immediate problems.  What I have not found yet was comments speaking about reaction disc missing and how this would effect things, if your push rod WAS properly adjusted.

The reason I consider them separate is that I believe I had the amount of adjustment available in my push rod to mate properly with my master cylinder.   The assumption would be that if the reaction disc was NOT properly placed, you wouldn't be able to adjust the pushrod out far enough to compensate for it's absence. (I believe the reaction disc's function is to be a small amount of buffer between metal components)

If I assume this is correct then I should be kosher. The reason I question it is because of the large amount of adjustment I personally had to make. (.575" outward) Granted this was on a car that is new to me, whose MC had been recently replaced by gentlemen of unknown mechanical skill, who had not gotten the brakes to function properly at the time of sale.

But, if I can get the booster out easily, then I will... if only just to clean it and paint it.  I'll shake it up and see if I hear the disc bouncing around in there.

Edited April 11, 2016 by DaveR

[sweatybetty]

1 hour ago, DaveR said:

One thing that was confusing was that when i pulled the adjustment rod out to adjust it (only far enough so i could get pliers onto the knurled section).... after a relatively short amount of travel it fell out of whatever cylinder was guiding it inside the brake booster. Less than half an inch of travel I would imagine.

I could tell because it was able to wiggle outside of the normally straight travel.  I was able to center it and slide it back into said cylinder after adjustment, but it left me a bit confused. I would assume that under normal brake operation it would need to extend at least that far, if not further, to fully press the master cylinder's piston. (i could be wrong though) What ensures that on the return stroke it successfully locates itself back into this cylinder? 

I have no idea if this means anything, but since the car isn't running I don't have a way to test the brake booster.

I realize that pulling out the push rod runs the risk of dropping the reaction disc, but is there another way to check if it is properly in place?  If I was so inclined can I simply remove the push rod and look?

 

here is a pic of the push rod and where it goes into the reaction disc.the reaction disc cannot go anywhere

 

Edited April 11, 2016 by sweatybetty

[DaveR]

I think your comment got hidden in the quoted text.

Quote

here is a pic of the push rod and where it goes into the reaction disc.the reaction disc cannot go anywhere

But anyway, thanks for that image. Looks like my assumptions about relative height are probably accurate. I bet if i went out there and measured how far my pushrod could be pulled before it escaped the cylinder I could guess if my disc was properly in place.

[sweatybetty]

the push-rod isn't attached to the disc. it just sits in a hole. you can pull the push rod out of the booster simply by pulling it and the rubber seal straight out. here is a pic of the booster taken apart.