66 Power Brake Booster

M
Last seen
Joined
Sep 14, 2019
Thunderbird Year
1966
Hi all. I have a 66 Thunderbird. I had a mysterious brake fluid lose. No leaks anywhere then no pedal. I believe it went into the power booster. Replaced master but now the pedal is slow to return once you take the pressure off. I've even moved the pedal back up with my foot. Been in touch with Power Boster Dewey and there could be an issue with the Midland Booster. Manual says undo the four nuts under the dash to pull it. Even with the seat out it looks like you need to be a yoga expert to do this.

Can I pull it from under the hood. There are four nuts that mount the booster to the brackets. The brackets should be fine. I'm not sure if I can undo the linkage from up top. I have heard from others that say their linkage needed to be cleaned up. Can I do this from up top?

Thanks.
 

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Hi all. I have a 66 Thunderbird. I had a mysterious brake fluid lose. No leaks anywhere then no pedal. I believe it went into the power booster. Replaced master but now the pedal is slow to return once you take the pressure off. I've even moved the pedal back up with my foot. Been in touch with Power Boster Dewey and there could be an issue with the Midland Booster. Manual says undo the four nuts under the dash to pull it. Even with the seat out it looks like you need to be a yoga expert to do this.

Can I pull it from under the hood. There are four nuts that mount the booster to the brackets. The brackets should be fine. I'm not sure if I can undo the linkage from up top. I have heard from others that say their linkage needed to be cleaned up. Can I do this from up top?

Thanks.
Yes once you have removed the brake light switch and have removed the he power booster rod. The hard part is getting to the 4 nuts, then The booster can be removed from under the hood. You don’t need to remove the master cylinder.
 
Yes once you have removed the brake light switch and have removed the he power booster rod. The hard part is getting to the 4 nuts, then The booster can be removed from under the hood. You don’t need to remove the master cylinder.
It's out. Basically like you said. The light is on the pedal on my car. The pedal linkage and booster rod slid right out. The linkage is free and looks fourfine.The nuts were a little tough but not too hard. Shipping to Booster Dewey next week. I should probably replace the master to booster gasket. Will look for that. Thank you for your response.
 
It's out. Basically like you said. The light is on the pedal on my car. The pedal linkage and booster rod slid right out. The linkage is free and looks fourfine.The nuts were a little tough but not too hard. Shipping to Booster Dewey next week. I should probably replace the master to booster gasket. Will look for that. Thank you for your response.

Looking at the spacer between the Master and booster. Mine isn't in such good shape. There seemed to be remnants of foam or a filter on it at one time. Also I'm not sure of the order and top or bottom. Any diagrams or suggestions. Shop manual is silent on it.
 
Looking at the spacer between the Master and booster. Mine isn't in such good shape. There seemed to be remnants of foam or a filter on it at one time. Also I'm not sure of the order and top or bottom. Any diagrams or suggestions. Shop manual is silent on it.
Update: Found it in a Comet manual that covered the Midland Booster. Odd it's not in my Tbird manual. There is spacer, filter material and nylon top. I thought there was filter remants. The nylon side goes to the master and the lobe goes down. Those two parts are carried by Macs. I guess a can reuse mine if I can add some filter material. Looks like it might have been like a window AC filter material. Oh and you measure the Master Cylinder rod leangth after the spacer assembly.
 
Also price it on parts123. Let me know if you need help looking it up, is yours a convertible?
 
Hi all. I have a 66 Thunderbird. I had a mysterious brake fluid lose. No leaks anywhere then no pedal. I believe it went into the power booster. Replaced master but now the pedal is slow to return once you take the pressure off. I've even moved the pedal back up with my foot. Been in touch with Power Boster Dewey and there could be an issue with the Midland Booster. Manual says undo the four nuts under the dash to pull it. Even with the seat out it looks like you need to be a yoga expert to do this.

Can I pull it from under the hood. There are four nuts that mount the booster to the brackets. The brackets should be fine. I'm not sure if I can undo the linkage from up top. I have heard from others that say their linkage needed to be cleaned up. Can I do this from up top?

Thanks.
No you have undo from the inside, and disconnect the booster rod from the brake pedal along with brake light switch, not easy at all. Good luck
 
Hi all. I have a 66 Thunderbird. I had a mysterious brake fluid lose. No leaks anywhere then no pedal. I believe it went into the power booster. Replaced master but now the pedal is slow to return once you take the pressure off. I've even moved the pedal back up with my foot. Been in touch with Power Boster Dewey and there could be an issue with the Midland Booster. Manual says undo the four nuts under the dash to pull it. Even with the seat out it looks like you need to be a yoga expert to do this.

Can I pull it from under the hood. There are four nuts that mount the booster to the brackets. The brackets should be fine. I'm not sure if I can undo the linkage from up top. I have heard from others that say their linkage needed to be cleaned up. Can I do this from up top?

Thanks.
No it has to be unbolted from the inside, 4 nuts hold it to firewall and you will need to remove the brake light switch, not an easy job just finished it back together on my 66
 
This was a long project but it's finished for now. Started with a fantom brake fluid leak. No signs of fluid anywhere. Then the brakes were slow to release for while. Then no brakes and pedal went to the floor. Changed the MC but they were still slow to release. So I think the easiest way is to pull the booster from the engine compartment. There are four nuts behind it that hold holds it to the bracket. It's a little tough to pull the booster off the brake pedal rod but I was able to. Got the booster rebuilt by Booster Steve and a new master. Now the brakes are a little agressive but all the issues seem to be gone. I know they don't fail often but check the one way valve on the booster housing. Mine was also bad. I would have liked the brakes to be a little less grabby but all is working well. I am using 3/8 fuel line for the vacuum. That's not really spec so wonder if that is contributing to the brakes being a little grabby. I can adjust to them but it would be great to hear if there is any easy way to get the brakes to be a little less aggressive.
 
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