Brake Master Cylinder Pushrod Issue
 

Looking at a video on YouTube, apparently there's supposed to be a crown shaped washer on the brake master cylinder Pushrod.

I suspect this washer fell into the brake booster itself upon removal. I have the Pushrod and the little metal puck thing, but can't find the washer thingy.

1. Can I replace the washer thingy easily? What's it called/part number?

2. If the old one fell into the booster (at the front of the opening there's a spring and a gap), can it stay there harmlessly or do I have to pull out the booster?

3. Is there a photo or diagram or video somewhere of how the Pushrod goes back into the booster, orientation of the little puck thing, etc?

Could you elaborate what part you are referring to.

https://c1552172.ssl.cf0.rackcdn.com/541058_x800.webp

Search YouTube for rebuild of that part. I'm sure I saw mention of a reference and it will show all the parts in order.

Attached a pic. My understanding is that it's a Booster component not a Master Cylinder component. It's what pushes against the master cylinder piston.

Honestly I don't even know what part I'm looking for. The only thing I can find on the entire internet is a YouTube video where he shows the parts but not how to put them back in.

A bunch of comments of people freaking out because there's nowhere online that explains how to put it back together.

And a response from Pelican Parts on their master cylinder DIY telling someone they probably need to replace the whole booster if the Pushrod can't go back in.

If need be I'll pull the booster and hopefully the locking ring fell into it and I can shake it out. But I still can't find anywhere that details how it fits back together.

So these parts came off on your brake booster? Never seen that happen. :dunno:

By the looks of it that retainer is what holds the pushrod in place when the master cylinder isn't there. Should be easy and obvious enough to stick that back together I would think?

That's what I figured too. First try to find that lock spring. Maybe with flexible magnet inside the booster front cavity. If you wedge the brake pedal in pressed position it's easier too see the location on the plate where the rod should be secured. That small part remains a mystery but could be obvious when you look at all the parts if it should be under the pushrod or between the rod and main cylinder.

Please post link to YouTube video you referenced.

https://youtu.be/CFK95zNMcf8


So the day I posted this, I was pissed off and went for a nap.

My wife and my dad decided to go play with the brake booster and see if they could find where that retaining ring went in order to not have me pissed off all evening lol.

My wife found it down in the bottom of the brake booster and almost had it out with a wire and hook. I took her idea and managed to hook it with the wire after putting a loop in it to use as a handle to give me some control over what direction the hook was facing. I was then able to hold my finger on it close to where we could pull it out, and she stuck a magnet on it and pulled the dang thing out! Hallelujah!

The little metal silver piece seats between the booster and the rod. Then the Pushrod goes on top of that. And then the retaining ring goes in after that.

I haven't yet done any of this. My problem is that I don't know exactly how far into the booster the retaining ring is supposed to seat?! I went to AutoZone to look at a booster but no auto parts store in the city stocks an E53 booster.

I'm about to head out to the garage to see if I can figure it out with some combination of seeing some kind of a wear mark, groove, or look at pedal travel to make sure I don't seat it too far in (although I suspect the Pushrod will just push the clip forward under pedal pressure anyway. Maybe that's how it's seating location is supposed to be determined??)

If anyone has any info on seating depth I'm all ears!