Brake Booster Rebuild Help

[ToolBoy]

Hello to all, 

It seems I have shot myself in the foot needlessly again. The expression goes "If it aint broke, don't fix it"   Well, I really fixed it. Bought the rebuild kit for 7 inch brake booster, bead blasted and cleaned it up, pulled it apart and got down to the "valve operating rod assembly"  There is a cylindrical rubber boot in the rebuild kit so I proceeded to rip off the existing rubber part, trusting that I would figure out how to disassemble and remove the springs etc to install the new one. Now I'm thinking the parts are permanently crimped on and not designed to be removed. I either need to find a way to dissassemble this part or order a replacement valve operating rod assy.or buy an entirely new booster if that is the only option. Can't figure out why that part is included in the kit if one can't remove the old one?  Any input is welcome. . . Thanks  Andy.

[Patcon]

 

[ToolBoy]

Thanks Patcon,  I read thru all the posts and comments on your Brake Booster topic but there doesn't doesn't seem to be any information that addresses my problem. 

[Zed Head]

Post #3/4 of the way down Page 3?  No good?

 

Edited March 4, 2020 by Zed Head

[ToolBoy]

Yes. actually very good. I didn't look at the following pages at first. Didn't realize the post was so deep. I'll pop the unit apart tomorrow. Thanks.

[ToolBoy]

Hello to all,  I understand that this topic was created a year and a half ago but I didn't acquire my Z till december and my booster is ripped apart now. Patcon  was super helpful by directing me to this conversation and I've poured through the discussion and the photos repeatedly. I am suspicious of the booster as it came on the car and I'm thinking it wasn't done right the last time.  I'm now doing my best to match up the new rebuild kit parts with what I have and preparing to reassemble after some final paint work I still need to do. This morning I put the poppet assembly back together and re-punched the 3 divets thanks to the input and courage you all provided. I have included a photo of how I'm thinking the unit will be reassembled with a few questions.  If anyone would take a look, I'd be real appreciative.

Questions. . . I didn't notice when I took it apart but I'm wondering if the key that holds the poppet assembly needs to be facing up so as not to fall out ever.

Also I'm thinking bearing/seal part "P" is to replace soft seal "L" . The new part is a really tight fit but once lubricated, I think it'll go in. Also thinking the metal ring side goes in first and installer pushes on the hard plastic side? And then it's followed by the serrated ring?

"I" is the old dust boot which I like better than the replacement and it's still pretty supple. 

The poppet assembly is also a super tight fit but with silicone grease it should go.

If anyone wants to chime in with comments I'm all ears. 

Thanks to all and stay well and prosperous,

Andy

 

 

[Patcon]

I am unsure on the seals. I did a lot of guessing there and just working through it by looking at the seal edges

The retaining key can probably go in any orientation because the rubber diaphragm will go in that slot and keep it in place. If I remember correctly...

[ToolBoy]

Thanks Patcon,      After I posted I started doing a preliminary assembly and I'm much more confident than I was. And you're right about the key. . . the big rubber diaphram holds it in. I had a hard time stuffing the bell shaped rubber piece on the central rod but it finally went in. Looking forward to getting it to close up in the end. That should be fun to figure out. Thought about modifying an oil filter wrench to make it the right diameter. Thanks for the feedback. . . 

[HappyZ]

@ToolBoy I’m hoping you can remember the assembly process.  I removed my booster and something doesn’t seem right with mine.  Regarding the parts you identified as D and N, those are the only two parts that come out of the assembly.  Does N slide onto D and then fit into C?  If so, does N get affixed to C with something like RTV?  Any help is appreciated.

i also started a thread with pics. The thread is titled “Brake Booster Questions - Please Look” in the subject.

[ToolBoy]

Hey Happy Z,  It's been a while but I haven't put the booster back in the car yet so I was able to remove the parts as shown. The push rod "D" is only stuck to the reaction disk "E" with the silicone grease and it's kept from falling out when the master cylinder is bolted in.  That push rod "D"seems to be centered with disk "N" that's pressed into the front of  "A". I was thinking that Disk "N" needs to seal against "D" but I'm hoping that vacuum will be sealed on the other side after the master cylinder is bolted on. Mine is holding vacuum when tested but I can't really test in the real braking world as I won't have the car running for some time. I've attached a photo of the front pulled apart to Illustrate. I wish I could say I have it assembled correctly but at some point I was winging it as I didn't take as many photos as I should have. Good Luck. . . Andy

[ToolBoy]

Not sure if that disk gets glued in, mine's just sealed with grease but might be a good idea.

[ToolBoy]

Ah. . . here. See page from FSM that lists parts that get silicone grease. . . calling it "plate and seal". Part can also be seen in second photo first column.