How Do I hate Rebuilt Components? Brake Booster

[Patcon]

I found a source for the diaphragms a couple of years ago but I would have to have bought a 1000 units. They weren't very expensive but I didn't figure I could ever get rid of even half that so I didn't do it.

[Captain Obvious]

I'm positive you wouldn't have sold more than a couple. I assume you never turned up a source for the internal rubber parts or the end seals?

Speaking of such things... I'm positive the Z isn't the only car that used those internal parts. Anyone have any theories of other cars that may have used the same internal conponents? Something easy to find like an old Maxima or Sentra perhaps?

Anyone know if Honda or Toyota used Hitachi brake components?

[Patcon]

Yeah, that's what I figured. I contacted a couple of booster rebuilders to see if I could source the parts through them but there is really no money in it for them so the interest wasn't there.

When I had a booster apart there was a part number on the large rubber diaphragm. I found that by googling but nothing in reasonable quantities. The real solution is to make these in small runs or find a rebuilder who has a source for ordering these parts...

[Captain Obvious]

My original diaphragm was OK, so I've got a spare one of those. What I would really like to have is a new valve assy. I found that my original one looked better than the crappy looking one that came in the "rebuilt" booster, but it didn't work right. So I'm running the crappy looking (but functional) one that I harvested from the rebuild.

I'm positive they used the same valve in many other cars, but I just don't have any source to confirm.

I can't rip a bunch of boosters apart in the junkyard just to check.

[Namerow]

On 9/15/2016 at 10:05 AM, Captain Obvious said:

Let me count the ways. 

Hey Captain O --  I've got a new way for you to hate remanufactured parts: 

Yesterday, while trying to install the rebuilt mastervac booster that I'd bought for my car (a Cardone unit, purchased from my local NAPA outlet), I discovered that the metric mounting studs (8x1.25) had been replaced with 5/16-24 SAE items!  The first signs of trouble were when the metric nuts would start on the stud threads but then jam.  At first, I thought maybe the stud threads were gunked up with paint, so I pulled the booster out of the car and tried to run a die down one of the studs, just to clean up the threads a bit.  When the die wouldn't start easily, I started to get suspicious.  I grabbed my thread gauge (metric) and discovered that I couldn't get a match with either the 1.25 or the 1.00 pitch.  Then the light-bulb went on!

How close are these threads?

So:  On diameter, near enough as to not matter.  On thread pitch, though, they're close enough to get things started but far enough off to chew things up if you go beyond that.  I'm just glad that I didn't get impatient and try to force 8mm nuts onto those studs. 

Oddly, the studs on the other side of the booster (that mount the brake master cylinder) were left as metric.  Go figure.

[Captain Obvious]

That's just so wrong. I mean, if you know ahead of time, it's not the end of the world. But with no notification about the change... That's just wrong.

Glad you got it figured out before you ran a nut fully down onto one of those studs.

How Do I Hate Rebuilts??!!

[240260280]

@Captain Obvious

 

I  just received a Cardone rebuilt booster like you and it had the same slathered silicon grease on the pitted push rod.

 

I first experimented with a spare one (pittted) and chucked it in my drill press and gently sanded it from 120 grit all the way up to 800. I did not try to sand out the deep pits and they still show badly.

I then spun the more pitted one (that came with the booster) but I hogged it at 50 grit until  the pits were removed. I then finished it all the way up to 2500. It turned out very nice and worked very well at holding a vacuum even with the narrower shaft.

Also in the collection below is an old one from a 240z that I tried to plug the pits with JB Weld then hand sanded. It worked just so-so.

I'm not sure about the matt coloured one. I think someone may have zinc plated it.

 

 

 

The rebuilt booster's seal works well with the hogged  push rod.

 

 

Edited July 12, 2018 by 240260280

[Captain Obvious]

Nice work! Certainly can't be worse than the original pitted finish! 

From my brief foray into that realm, I found that front vacuum seal had significant compliance and held pretty snug against the shaft. You should be able to tell how much metal you removed by comparing your sanded one to the originals.

The JB weld rod looks nasty. Like someone grabbed it with pliers at some point. And the one you have labeled "unknown"? I don't think that's zinc plating. I think someone sand blasted it. That one may clean up nice with the sandpaper treatment.

[240260280]

I'm going to paint the shell this evening and thoroughly follow your lead and degrease it.

[Captain Obvious]

Well if yours is like mine, (and based on your description of slathered silicone grease, I bet it is) then you absolutely need to degrease first.

And even so, I wouldn't be surprised if you don't get some fish-eye like I did. With that much silicone floating around, I think it's inevitable.

Did you split the clamshell open, or are you just working on the parts you can get to from the outside?

[240260280]

Just working on the outside.  It held 15" vacuum for 15min so that is good for me.

I just used the Duplicolor degreaser and some high-build primer followed with a satin black. It looks ok. 

Luckily the pits are not so bad on the shell.

I also Zinc plated the push rod to reduce future rust.

 

[siteunseen]

What are you guys doing for the sticker on the OE? I slowly scraped mine off then Gorilla Glue'd it to the new one. Holding up good so far.