Posted October 15, 20177 yr comment_532377 My 240Z has the early design master cylinder. I recently replaced the vacuum servo unit with the MSA one. When everything was reassembled and brakes were bled, the brake pedal was very stiff. When I removed the master cylinder the piston only moves about 1/8 of an inch when I push on it. My question is how much force does it take to move the MC piston? Is the MC shot? Link to comment https://www.classiczcars.com/forums/topic/58736-1971-master-cylinder-question/ Share on other sites More sharing options...
October 15, 20177 yr comment_532378 Not a lot of force, mine was bad, same early design. Ended up going wilwood. Link to comment https://www.classiczcars.com/forums/topic/58736-1971-master-cylinder-question/#findComment-532378 Share on other sites More sharing options...
October 15, 20177 yr Author comment_532380 Did you have to reroute the front and rear brake lines?Sent from my iPad using Tapatalk Link to comment https://www.classiczcars.com/forums/topic/58736-1971-master-cylinder-question/#findComment-532380 Share on other sites More sharing options...
October 15, 20177 yr comment_532424 I bent my own lines, it was a pain, but it ended up working. They are switched, it's hard to see in the picture. Link to comment https://www.classiczcars.com/forums/topic/58736-1971-master-cylinder-question/#findComment-532424 Share on other sites More sharing options...
October 17, 20177 yr comment_532594 Make sure there is free play in the rod, since you changed the booster Sent from my SM-G930V using Classic Zcar Club mobile Link to comment https://www.classiczcars.com/forums/topic/58736-1971-master-cylinder-question/#findComment-532594 Share on other sites More sharing options...
October 17, 20177 yr comment_532610 2 hours ago, gira said: Make sure there is free play in the rod, since you changed the booster Sent from my SM-G930V using Classic Zcar Club mobile Hard to tell, but I think there is, it's depth matches stock. Link to comment https://www.classiczcars.com/forums/topic/58736-1971-master-cylinder-question/#findComment-532610 Share on other sites More sharing options...
October 17, 20177 yr Author comment_532613 Make sure there is free play in the rod, since you changed the booster Sent from my SM-G930V using Classic Zcar Club mobile Which rod? The booster moves freely with the brake pedal without the MC installed. With the MC installed there is almost no movement. Does anyone have any experience with the remanufactured master cylinder available from Napa? From the photo it looks just like the OEM with the name scratched off. Sent from my iPad using Tapatalk Link to comment https://www.classiczcars.com/forums/topic/58736-1971-master-cylinder-question/#findComment-532613 Share on other sites More sharing options...
October 17, 20177 yr comment_532615 2 minutes ago, Brushz said: Which rod? The booster moves freely with the brake pedal without the MC installed. With the MC installed there is almost no movement. Does anyone have any experience with the remanufactured master cylinder available from Napa? From the photo it looks just like the OEM with the name scratched off. Sent from my iPad using Tapatalk Have them bring it to the store, if it's a stock reman then you are good, most likely it will be a knock off. Link to comment https://www.classiczcars.com/forums/topic/58736-1971-master-cylinder-question/#findComment-532615 Share on other sites More sharing options...
October 17, 20177 yr Author comment_532616 Have them bring it to the store, if it's a stock reman then you are good, most likely it will be a knock off. Can the guts from the new one be used to rebuild my old one?Sent from my iPad using Tapatalk Link to comment https://www.classiczcars.com/forums/topic/58736-1971-master-cylinder-question/#findComment-532616 Share on other sites More sharing options...
October 17, 20177 yr comment_532617 The length if the rod that comes out of the booster and contacts the cup at the rear of the master cylinder. This length is very important and many times when you change the brake booster it throws the adjustment off. It may be slightly push the master cylinder piston in which messes everything up.Sent from my SM-G930V using Classic Zcar Club mobile Link to comment https://www.classiczcars.com/forums/topic/58736-1971-master-cylinder-question/#findComment-532617 Share on other sites More sharing options...
October 17, 20177 yr comment_532618 5 minutes ago, Brushz said: Can the guts from the new one be used to rebuild my old one? Sent from my iPad using Tapatalk They make rebuild kits for them, depends on what is wrong with yours. Link to comment https://www.classiczcars.com/forums/topic/58736-1971-master-cylinder-question/#findComment-532618 Share on other sites More sharing options...
October 17, 20177 yr Author comment_532632 I think I may have it figured out. The rod coming out of the vac is longer than the original. I'll swap the end nut with the one from the original one and hopefully the will solve the problem. Sent from my iPad using Tapatalk Link to comment https://www.classiczcars.com/forums/topic/58736-1971-master-cylinder-question/#findComment-532632 Share on other sites More sharing options...
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