Monero_Currency

Hi,

I recently inherited a 1979 928, its been sitting for a while so I'm going through and trying to bring it up to spec.

Anyway working on the brakes and clutch. Brake master & clutch masters have too much corrosion in the bore for me to rebuild. Same for the clutch slave. All the calipers turned out great, except drivers front. Anyway I'm trying to determine what size the brake booster is, the outside diameter is 10.5 in.

I believe this year should have had a 9 in, but I'm too much of a noob to know if the or 9 or 10 in designation is an internal diameter or external diameter.

If it is a 9in diameter where can I get it rebuilt if necessary? I saw someone mention a service in a post weeks ago, but I'm unable to find it.

Looking for a cheap stock front driver side caliper as well.

Thanks in advance!

ROG100

Hi Welcome to the 928 World.

Sounds like a 10" to me as it measures close to that. That would be good news as the smaller 9" is NLA.
New booster is $289.95 but I have never heard of a rebuild service.

If you want a good used booster and the caliper call Mark or Tom at 928 International

Rob Edwards

Give Karp's Powerbrake a call,

http://www.karpspowerbrake.com/

They restored William's 9" booster on the Minerva build, and did a beautiful job. I'd bet they can do the same on a 10" booster as well, though $289 for a new one from Roger is almost certainly a better value, and much quicker turnaround.

Mark Anderson

I do have a new 9" booster in stock 😊

hlee96

Mark, how much is that NLA 9" booster?

hacker-pschorr

White Post Restorations rebuilt the clutch master in my 78, and I'll be sending them a booster soon.

http://www.whitepost.com/brake.html

Their rebuilt masters are superior to new IMO. They bore them out and insert a brass sleeve. Rebuilding the clutch master also eliminates the issues of the piston length being different.

Monero_Currency

Thanks guys, exactly what I needed to know.

Rob Edwards

Mark's new 9" booster ****, with QC dot and proper Ate sticker:

Guy

While it's a small consideration, the 9 inch booster makes changing the clutch master (if applicable) much easier.

My 79 has the 9 inch. The clutch master was downright easy.

hacker-pschorr

I fail to understand the importance of the 10", at least in the early cars... I have S4 brakes in my 79 with the 9" booster and even on the track I've never needed more brakes.

Mark Anderson

$495 and just one left

hlee96

Mark, please reserve this 9" booster for my next purchase.
Thanks
Hoi

Mark Anderson

its yours