What Are These 15/16 inch Brake Cylinders From?

[kwilford]

I got a bunch of odd parts from Kat when I bought her SportWagon. Sorting through it today, I found these two wheel cylinders. One is NOS, the other is used (but very re-buildable). They are marked "Opel", and are "left and right" (based on the difference in connections), and have a 15/16 inch bore. The NOS cylinder is made by F.A.G. and looks modern (blitz is '70's or 80's vintage) while the used one is made by PBR (In Australia!) and looks older, as the "Opel" writing is the old stylized "oval" version.

I know the standard GT and Manta/Ascona rear wheel cylinders are 5/8 ", and a recommended upgrade (with a proportioning valve) are the 3/4 " cylinders. What the heck are THESE from? They are HUGE! Are they useful? The mounting is similar, but the hole is the backing plate that they would sit in would have to be 32 mm, versus 28 mm on a GT, so they won't work for that. I haven't taken off the rear brakes on the SportWagon yet, but I presume they aren't for that. Oh, if you can't read the numbers in the photos, they are # 762 (and 263 47 on the back) and #511 (and 8 263) for the NOS and used cylinder respectively.

Any ideas?

[kwilford]

I just realized I hadn't loaded the photos. They are now attached. Any ideas?

[BQS4]

Keith;
I know these say "Opel" on them, but, they are not like any I have seen. All the wheel cylinders I have seen have the feed line and the bleeder at a 90 degree angle to the cylinder, not at an angle, like the pics you are showing.

[oldopelguy]

Maybe they're for a "big" Opel, like say, an Admiral? I'll check in a couple of weeks for you (and me ) when I get home.

[opelbits]

Me thinks the the Opel and PBR (Australian brake parts company) logos could mean they are from an Australian market Holden. Many of the Holdens were Opel based. Could be a Commodore, Monaro, or Torana part.

[GTJIM]

Had a look at the PBR site but the part numbers for wheel cylinders bear no resemblance to the three digits cast on to the sample. I think it may just be casting identification numbers and not a part number.

PBR makes vast numbers of brake cylinders and exports all over the world.

[MantAscona]

Perhaps they are front wheel cylinders from a Kadett with front drum brakes. The bore size is appropriate for that.

Duane

[kwilford]

Originally Posted by MantAscona Perhaps they are front wheel cylinders from a Kadett with front drum brakes. The bore size is appropriate for that.

Ah, that sounds possible. Anyone out there have a front drum Kadett who knows this stuff?

[MantAscona]

Also, the angle of the fitting where the line attaches and "left/right" markings are indicative of front brake applications.

Duane