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Über Genius
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Back to the brake booster.
You had the pedal get sucked to the floor...
If you also had white smoke out the tailpipe then the Master Cylinder is shot and the booster is full of fluid.
Your brake pedal will start going to the floor again soon if the M/C is leaking.
 
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The engine & transmission seemed to operate really well considering. I’d leave the carburetor alone. I think you were suffering from a vacuum leak at the brake booster & perhaps problems with the master cylinder as FO said in the video. I had a really slow undetectable leak from my MC into the brake booster over time and didn’t know it until I replaced both, the booster was full of brake fluid when I removed it. Focus on the brakes first. Be careful with the fuel pump, I’d like to see it bolted on with a bracket. You can make it safer for little money. From what you said your grandpa ought to be well aware of the things hear from us, just thinking these things are pretty important. It’s great to see you having a blast in it. Keep the videos coming 😏
 

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1969 Opel Gt 1.9 Automatic
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Discussion Starter · #123 · (Edited)
Well the black part of the dash has a massive crack in it by the tachometer. What I thought was if you cut it out you can always jb weld it back in or something.

I think we might take the brake booster and the Master cylinder out and take a look at it. I think the fuel pump should be safe because we drilled holes in the floor and bolted the fuel pump with two bolts.
 

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1970 Opel Gt - Purchased July 1972 - Chartreuse - restored - 3000 miles as of 02-16, 2021 -
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The engine & transmission seemed to operate really well considering. I’d leave the carburetor alone. I think you were suffering from a vacuum leak at the brake booster & perhaps problems with the master cylinder as FO said in the video. I had a really slow undetectable leak from my MC into the brake booster over time and didn’t know it until I replaced both, the booster was full of brake fluid when I removed it. Focus on the brakes first. Be careful with the fuel pump, I’d like to see it bolted on with a bracket. You can make it safer for little money. From what you said your grandpa ought to be well aware of the things hear from us, just thinking these things are pretty important. It’s great to see you having a blast in it. Keep the videos coming 😏
Hey Cub, I have also replaced the old brake booster with the newer larger one and a new master cylinder at the same time and I also found that the old booster had a pretty good amount of brake fluid in it however I have no idea how that happened - do you by chance know. As far as I know the old booster still worked but I have no idea how the fluid ended up in the booster as if memory serves the master cylinder, that I just replaced this year, was pretty close to new as well but not having a strong understanding of the master cylinder/brake booster relationship I would love to know how it pumped brake fluid into the booster unit. Thanks, Carl
 

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Detritus Maximus
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The seal at the back of the master where it meets the booster can leak fluid that then gets trapped in the booster. Since no one ever checks inside the booster when replacing the master, that fluid could be years or decades old. What First Opel said is true, too. Get enough fluid in the booster and it gets sucked into the motor via the vacuum booster hose. Puts out white smoke that most mistake for a head gasket or something.
 

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Hey Cub, I have also replaced the old brake booster with the newer larger one and a new master cylinder at the same time and I also found that the old booster had a pretty good amount of brake fluid in it however I have no idea how that happened - do you by chance know. As far as I know the old booster still worked but I have no idea how the fluid ended up in the booster as if memory serves the master cylinder, that I just replaced this year, was pretty close to new as well but not having a strong understanding of the master cylinder/brake booster relationship I would love to know how it pumped brake fluid into the booster unit. Thanks, Carl
It sure is sneaky stuff isn’t it, I didn’t remember having to hardly ever top off the reservoir over the years but sure enough when I removed the booster there it was! And a good pint or so. Good question, I assume just like the rear brake cylinders that the walls of the master cylinder get pitted over time and develop a slow, slow leak.

On the rear cylinders all is fine until you replace the pads and the seals are pushed further in towards middle of the cylinder, this exposes the pitted walls of the cylinder that used to reside happily, undetected, slowly developing small pits inside of the hydraulic chamber of the cylinder behind the seals. Unless you religiously bleed your brakes every year (I don’t) there’s no slowing the process of the moisture developing, hydraulic brake fluid is somewhat like a sponge. It made me wonder if during the brake bleeding process this is when the MC fluid leaks it’s worse, then similar to the rear cylinders the pits are behind the seals during normal operation. The brake bleeding process is the only time that I can account for a good bit of fluid use in my experience.

I’ve never taken the MC apart so I’ll defer to someone who has. I can’t be sure as to if the metal pits easily like the rear cylinders (that’s just an educated guess) or perhaps it’s just the normal wear & tear on the rubber etc inside. Unfortunately I don’t have a better answer but the fluids only escape route past the seals does seem to be inside of the booster.
 

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1969 Opel Gt 1.9 Automatic
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Discussion Starter · #127 ·
Well I got back from a AABC(American Austin Bantam Club) Meet. We got the valves adjusted on the Opel. Most of the valves were too tight. Then we figured out that the trans is leaking. It's an auto. One of the lines are leaking. We also put silicone on the plug wires because they were shorting out and now with the valves adjusted it runs great!

Sam
 

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1969 Opel Gt 1.9 Automatic
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Discussion Starter · #128 ·
I forgot to say that I am not using the radio that I bought for $10. I am using a roadmaster radio that fits almost perfect in the opel. I just have to cut out like a few milimeters of plastic to make it fit. It even comes with speakers! I don't have any pics of it.
Sam
 

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Detritus Maximus
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That is the normal fit for many radios 'back in the day'. Fords were the same way. The factory radios were slightly narrower and sometimes taller. The aftermarket units almost always required cutting and trimming to fit, but often the amount was just small enough to make you wonder why.
 
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Well I got back from a AABC(American Austin Bantam Club) Meet. We got the valves adjusted on the Opel. Most of the valves were too tight. Then we figured out that the trans is leaking. It's an auto. One of the lines are leaking. We also put silicone on the plug wires because they were shorting out and now with the valves adjusted it runs great!

Sam
I don't mean to hijack your thread, but I know guy who is just as obsessed with American Bantam pickups as I am with Opels lol. Would you happen to know if anyone was trying to sell one at that meet? He's been looking for one for years. Feel free to PM me ☺
 
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Über Genius
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A lot of aftermarket radios of that era had adjustable posts. It's hard to tell just by looking but they are.
 
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