69 javelin with power drums

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   Ok so I just spent the last 3 years completely restoring my 69 javelin from a shell. The car is finally finished but I am having some dificulty with my brake system. I do know that the drum brakes are known to have a very short travel which my javelin has. The issue I am running into is the brakes don't feel like they stop the car as well as they should. I have front drum with power. And my pedal says safe command. My entire brake system is new.brake lines wheel cylinders drum pads spring sets, drum
 booster and master cylinder. The proportioner has been rebuilt and works properly. My biggest question is, is there a specific master cylinder I can get for this brake system. I think I may have the wrong one. I do know there is a master for disc and drum but is there a specific master for drum power as opposed to drum manual. Any help is greatly appreciated. Thanks

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Jav69 Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Apprentice Joined: Aug/30/2016 Location: Lake Bluff IL Status: Offline Points: 56	Post Options Post Reply Quote Jav69 Report Post Thanks(0) Quote Reply Topic: 69 javelin with power drums Posted: Aug/13/2018 at 10:08pm
	Ok so I just spent the last 3 years completely restoring my 69 javelin from a shell. The car is finally finished but I am having some dificulty with my brake system. I do know that the drum brakes are known to have a very short travel which my javelin has. The issue I am running into is the brakes don't feel like they stop the car as well as they should. I have front drum with power. And my pedal says safe command. My entire brake system is new.brake lines wheel cylinders drum pads spring sets, drum booster and master cylinder. The proportioner has been rebuilt and works properly. My biggest question is, is there a specific master cylinder I can get for this brake system. I think I may have the wrong one. I do know there is a master for disc and drum but is there a specific master for drum power as opposed to drum manual. Any help is greatly appreciated. Thanks

farna Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Moderator Lost Dealership Project Joined: Jul/08/2007 Location: South Carolina Status: Offline Points: 19676	Post Options Post Reply Quote farna Report Post Thanks(0) Quote Reply Posted: Aug/14/2018 at 6:09am
	Yes, there is. There is also an adjustment for the pushrod in the power booster. The spacing of the mounting holes is usually different on manual and power master cylinders so they don't swap. There is a difference in the depth the pushrod goes in. The pushrod should extend 1" from the MC mounting face to the end on the single diaphragm unit, 1.185-1.200" on the double unit (AMX should have a single). If the pushrod isn't long enough you will have weak feeling brakes. If it's too long they will be very touchy! You can go with trial and error, but it's a PITA to remove the MC several times. You might have to to get the feel you want. Other than the pushrod all the MCs are the same -- 1" bore, same stroke.
	Frank Swygert

Jav69 Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Apprentice Joined: Aug/30/2016 Location: Lake Bluff IL Status: Offline Points: 56	Post Options Post Reply Quote Jav69 Report Post Thanks(0) Quote Reply Posted: Aug/14/2018 at 6:38am
	that sums things up well. I do have the right MC then and I have adjusted the push rod right. Maybe I still just have air on the lines.

farna Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Moderator Lost Dealership Project Joined: Jul/08/2007 Location: South Carolina Status: Offline Points: 19676	Post Options Post Reply Quote farna Report Post Thanks(0) Quote Reply Posted: Aug/16/2018 at 5:37am
	I'd try bleeding again, but if it still doesn't feel right try lengthening the rod maybe 1/16" and see if it helps.
	Frank Swygert

Jav69 Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Apprentice Joined: Aug/30/2016 Location: Lake Bluff IL Status: Offline Points: 56	Post Options Post Reply Quote Jav69 Report Post Thanks(0) Quote Reply Posted: Aug/16/2018 at 6:37am
	Funny you said that cause I just did that last night and there was a ton of air in the middle of the line. Thanks all for your input