grob main wheel and brake disk

does anyone know the Parker/Cleveland part number for the brake Disk
used on a Grob Twin II fixed gear which used a Cleveland caliper? Glider made about 1981.
I'm aware of the Dot 3/4 compatible O-ring used in the caliper.

Thanks,
Scott

I had ours off of the club twin II recently and took a photo of the data plate. Here is the info on ours -
Model - 40-97A
Size. - 6.00 - 6
Static rating 2500 ( I assume this is pounds!)
Wgt. 5.8. ( again, assume pounds)

On the backside of the disk there are numbers following numbers stamped into it -- 26A 233
Ours accepts the 6.00 x 6 tire.

Hope,this helps, Mark Guay

My bad - numbers off of the data plate refer to the wheel hub. The 26A 233 number were stamped into the bachdide of the brake disk/rotor and the only identifying information on it.

On Tuesday, July 17, 2018 at 10:38:55 AM UTC-5, Scott Williams wrote:
does anyone know the Parker/Cleveland part number for the brake Disk
used on a Grob Twin II fixed gear which used a Cleveland caliper? Glider made about 1981.
I'm aware of the Dot 3/4 compatible O-ring used in the caliper.

Thanks,
Scott

after a couple hours on the computer, I found a listing on an archived Cleveland
application chart, seems to call out;
disk, #164-02601
caliper, #30-63A, But the O-rings have to be changed out to dot 3-4 compatible rings.
linings#066-10500
wheel, #40-97A

thanks,
Scott

On Tuesday, July 17, 2018 at 10:38:55 AM UTC-5, Scott Williams wrote:
does anyone know the Parker/Cleveland part number for the brake Disk
used on a Grob Twin II fixed gear which used a Cleveland caliper? Glider made about 1981.
I'm aware of the Dot 3/4 compatible O-ring used in the caliper.

Thanks,
Scott

Further a Cleveland/parker part # for a chrome disc is 126-12601

On Tuesday, July 17, 2018 at 10:38:55 AM UTC-5, Scott Williams wrote:
does anyone know the Parker/Cleveland part number for the brake Disk
used on a Grob Twin II fixed gear which used a Cleveland caliper? Glider made about 1981.
I'm aware of the Dot 3/4 compatible O-ring used in the caliper.

Thanks,
Scott

Even further,
you need an EPDM #224 o ring, for dot 3-4 compatibility, hardness shore 70
and the torque plate number might be Cleveland 075-03700

OK, my bad, looking to learn......what was the original hydraulic system? If mineral oil, I can see the O-ring swap, otherwise, I "believe" ANY DOT fluid works in ANY system (other than DOT 5 which REALLY SUCKS WATER OUT OF THE AIR).
So, you can run ANY DOT brake fluid in any DOT system, DOT 5 just means a lot more fluid changes.
So, DOT 1-4 and DOT 5.1 are all compatible.

Again, just asking for my edumafication as well as others (misspelling intentional).

On Friday, July 20, 2018 at 2:49:20 PM UTC-4, Charlie M. (UH & 002 owner/pilot) wrote:
DOT 5 which REALLY SUCKS WATER OUT OF THE AIR).

Are you sure about this? Sounds like you are, but DOT 5 brake
fluid is silicone based, isn't it? Hydrophobic, as I read it.
Silicone brake fluid is a favorite with some antique car owners,
since it doesn't absorb water, which rusts the interior of the
brake system. I've got it in my old cars. It has other problems,
like being harder to bleed, though.

Or I could be completely wrong again.

Jim Beckman

On Tuesday, July 17, 2018 at 10:38:55 AM UTC-5, Scott Williams wrote:
does anyone know the Parker/Cleveland part number for the brake Disk
used on a Grob Twin II fixed gear which used a Cleveland caliper? Glider made about 1981.
I'm aware of the Dot 3/4 compatible O-ring used in the caliper.

Thanks,
Scott

Well,
to the best of my knowledge, and the Grob 103 twin II manual, and service bulletin OSB 315-17, .
the master cylinder was a modified Magura motorcycle part, which might have been original equipment on BMWs, maybe a R100? which uses dot 3 fluid.
The original equipment caliper is a Cleveland/Parker Hannifin 30-63A, which has a Buna-N O ring( MS28775-224) for use with petroleum based aircraft hydraulic fluid,
I think it was easier and cheaper to change the caliper O ring than to change the master cylinder seals.
The "O ring swap" I mentioned was intended to ensure caliper O ring compatibility with the Brake fluid indicated in the flight manual.( dot 3)
If someone simply replaced either the caliper or just the O ring with the Cleveland called out part number, this would result in the Cleveland O ring swelling over time. That is something you don't want in a caliper.
The ID label on our Grob 103 caliper should be labeled "DOT 3" but is not (Yet).
Larry Suter, on rec aviation Jan. 6th 2015 started a thread that covered it better than I.
If I'm incorrect, please post.
Thanks,
Scott

Ummmm....yes, I am very happy with my post.
Pretty much ANY DOT fluid is cross compatible EXCEPT DOT 5.
DOT 5 "will work", but it is even MORE water hungry than others. I do not believe it is a seal issue, it is water absorption issue. Thus, race cars is fine, other uses, sucks.

Now, mineral based fluids vs. DOT fluids is a different matter. Thus my question.

Oh, and to accentuate this, if you have an old system that uses DOT 1, using DOT 1-4 AND 5.1 is fine.

Yes, I made a bold statement, I will do my best to provide GOOD relevant links to prove, not just me stating it. Say, within 24hrs?