Brake Servo Questions

[jp-]

Basically, the piston of the booster is supposed to work with the brake pedal. The pedal return spring(s*) is what returns the pushrod when you let off the brakes. The pushrod isn't going to go out far enough to fall out. Here's a good video explaining how to adjust the booster pin/pushrod. I used the clay method, which worked fine. Biggest thing is not to have it too tight.
*Note, the booster pedal towers should have two long internal springs to return the pedal (and booster pushrod).

https://www.youtube.com/watch?v=WI_CXBJ6J3E

[westbound]

Basically, the piston of the booster is supposed to work with the brake pedal. The pedal return spring(s*) is what returns the pushrod when you let off the brakes. The pushrod isn't going to go out far enough to fall out. Here's a good video explaining how to adjust the booster pin/pushrod. I used the clay method, which worked fine. Biggest thing is not to have it too tight.
*Note, the booster pedal towers should have two long internal springs to return the pedal (and booster pushrod).

https://www.youtube.com/watch?v=WI_CXBJ6J3E

Thanks JP! Your post is very helpful! I bought the tool in the video to properly adjust the gap between the master cylinder and the servo pin. I'm not sure why others are saying you should never adjust the servo pin? That doesn't make sense to me - then why have the pin be adjustable in the first place. My pin definitely needs to be adjusted.

Follow-on question, my master cylinder looks "newer" (not the original). Fluid looks clean but can never hurt to flush and replace it. It has a slow leak coming from where the plastic reservoir body mates to the master cylinder. In the shop manual, (70.30.01), it describes a bolt that secures the reservoir body to the master cylinder housing. I think my bolt is loose because the reservoir is slightly twistable from side to side. Has anyone had success tightening this bolt, or should the whole unit be replaced? I'm wondering if I can tighten the bolt without draining the reservoir (using very clean tools) - to avoid having to bleed the system.

Option 1: tighten bolt without draining any fluid and no bleeding
Option 2: drain fluid, tighten bolt, replace w/ new fluid/bleed
Option 3: replace MC, new fluid/bleed

Any thoughts? Thanks!

[jp-]

Glad to help.

Yeah, my booster pin was pretty close, but I still had to move it some also. Always better to check it. And as you say, if your master cylinder is not stock, the booster pin location could be way off anyway.

If you can access the bolt to tighten the reservoir, I would try it with clean tools just to see, before buying a replacement. On some of them there are two little screws under the front that hold the reservoir on (not inside the reservoir).