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Discussion Starter #1
I have searched through this forum and frankly I'm more confused than before.

I have a hybred car. As near as I can tell the front end and brakes are from a 1970's 1900 GT. The front brakes are disc and the rear are drum. The master cylinder however, appears to be from a Kadett (the 22mm type, picture below) and has given up. When I inspected it I determined that it was not rebuildable.

I haven't been able to find a replacement for the MC, even OpelGtSource is out of stock. I have sent emails to other suppliers but so far I haven't heard back. In the meantime I was thinking of swapping the stock for something else, hopefully readily available. I've read that some have used BMW, Isuzu, Honda and Volvo MC's. I am looking for one that takes the least modification to install and will work with the drum and disc brakes. Most of the threads I've read here have involved rotor, caliper and even rear brake upgrades. These usually also involve major modifications.

Ideally, I'd like a straight bolt-on with maybe some brakeline re-routing. I have plenty of room under the hood so fitment is not really an issue. Any help is greatly appreciated.

Jim H
 

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Perhaps a good used one to tide you over till OGTS gets stock again? Keep it simple and no modifications required
 

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Opel Key Master
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The cylinder pictured is a Kadett cylinder upside down. It has an offset reservoir and will not cross with a GT. GTSource has these brand new, just send them that picture. He will also send a rebuild kit in case the seals internally are old and not in the best shape. Send the picture as he doesn’t know ends and outs of a Kadett
 

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Discussion Starter #5
The cylinder pictured is a Kadett cylinder upside down. It has an offset reservoir and will not cross with a GT. GTSource has these brand new, just send them that picture. He will also send a rebuild kit in case the seals internally are old and not in the best shape. Send the picture as he doesn’t know ends and outs of a Kadett
The pictured MC is listed by Cardone as the Kadett model. I saw a GT master cylinder on GTSource but I didn't see the Kadett and Gil is out of the GT MC right now. The MC in the car now is pitted with rust. I'm going to try honing it out and see if I can get it good enough to rebuild. If not I'll see if Gil has one at a reasonable price.

My main concern is that these are getting harder to find and very expensive. I thought that if I could swap in a more common MC without any major modifications it would make maintenance easier. That way I can keep an original MC in storage so when I want to put it back to stock (ex. when I sell it) I can without too much trouble.

Thanks for the help. JH
 

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Opel Key Master
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Gil doesn’t list Kadett parts in his website, you just email him a picture and he has a bunch of those new, but couldn’t tell you one from another as far as fitment. I’ve gotten 2 of that style from him in just the last couple months. Fitment is for a 68-70 Kadett. Your car is custom so you could maybe find plenty of brake setups that work better.
 

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Opeler
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master cylinders

I have searched through this forum and frankly I'm more confused than before.

I have a hybred car. As near as I can tell the front end and brakes are from a 1970's 1900 GT. The front brakes are disc and the rear are drum. The master cylinder however, appears to be from a Kadett (the 22mm type, picture below) and has given up. When I inspected it I determined that it was not rebuildable.

I haven't been able to find a replacement for the MC, even OpelGtSource is out of stock. I have sent emails to other suppliers but so far I haven't heard back. In the meantime I was thinking of swapping the stock for something else, hopefully readily available. I've read that some have used BMW, Isuzu, Honda and Volvo MC's. I am looking for one that takes the least modification to install and will work with the drum and disc brakes. Most of the threads I've read here have involved rotor, caliper and even rear brake upgrades. These usually also involve major modifications.

Ideally, I'd like a straight bolt-on with maybe some brakeline re-routing. I have plenty of room under the hood so fitment is not really an issue. Any help is greatly appreciated.

Jim H
ATE was the mfr, they show a "classic " category ... ATE Classic
cant say you can get them in the US but might be able to guide you to a substitute.
 

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Discussion Starter #8
I got a rebuild kit from GT Source. But after rebuilding the mc I inspected the rear wheel cylinders - they were rusted solid! So, I ordered a set of cylinders.
This car has been sitting for 14 years, so I should have inspected the cylinders first thing. I've replaced some of the brake lines and now I'm wondering if I should replace all of them just in case.
JH
 

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Über Genius
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Yes, you should replace anything made of rubber. The metal lines will be fine unless there was water in the brake fluid. The rubber lines swell up and make it impossible to get the brakes working right.
 
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