68 AMX brakes Which way to go??

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Working on a 68 Amx that is kind of a time capsule. Bought from original owners family. Very original, clean and complete. My dilemma  is this: do I leave the manual drum system or convert to power discs? It has very few miles on a major brake job by old owner. Over 1k on the repair order. I have not owned a drum brake vehicle since 1978. Will I be happy with the drums?  My gut tells me to leave it stock.

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BU1 Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Aug/11/2016 Location: MN Status: Offline Points: 2012	Post Options Post Reply Quote BU1 Report Post Thanks(0) Quote Reply Topic: 68 AMX brakes Which way to go?? Posted: Nov/10/2019 at 7:57pm
	Working on a 68 Amx that is kind of a time capsule. Bought from original owners family. Very original, clean and complete. My dilemma is this: do I leave the manual drum system or convert to power discs? It has very few miles on a major brake job by old owner. Over 1k on the repair order. I have not owned a drum brake vehicle since 1978. Will I be happy with the drums? My gut tells me to leave it stock.
	AMO #2726 #1 1968 AMX Rally Green 343 Z code 4spd since 1975 #02642 #2 1968 AMX Rally Green 290 N code 4spd since 2019 #02959

amx007 Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Joined: Dec/31/2008 Location: stone pk Status: Offline Points: 750	Post Options Post Reply Quote amx007 Report Post Thanks(0) Quote Reply Posted: Nov/11/2019 at 7:11am
	I owned drum brakes for years in the early days I had no issues even in rain. though a little 290 in my amx i would drive it since there new any ways you can always convert to disc it’s a pricy convert
	dream red white and blue 1968 Chicago auto show amx 290 4 speed 1969 driver Amx 290 auto

S Curry Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Aug/16/2012 Location: Iowa Status: Offline Points: 598	Post Options Post Reply Quote S Curry Report Post Thanks(0) Quote Reply Posted: Nov/11/2019 at 8:07am
	Have a manual transmission? Engine compression works good for getting it slowed down. AT may require more anticipation. I have a '70 AMX with GoPack with drum brakes. Must of optioned the disc's out of the order....if it is a cruiser, leave it and get used to them. If you live in a area with a lot of traffic...maybe disc's are the way to go. Guess i grew up with drum brakes in the 60's-70's and know what to expect.
	SC

ramblinrev Members Profile Send Private Message Find Members Posts Add to Buddy List Moderator Group Joined: Dec/28/2008 Location: Wisconsin Status: Offline Points: 11535	Post Options Post Reply Quote ramblinrev Report Post Thanks(0) Quote Reply Posted: Nov/11/2019 at 8:20am
	How recent is the expensive brake job? And how well do the brakes work? And how do you intend to drive it? Properly working drum brakes are fine in many circumstances. You do have to get used to how different they are from power disc brakes on our modern vehicles.
	74 Hornet Hatchback X twins (since 1977) 62 American Convertible (still worth the $50 I spent in 1973!) AMCRC #513, AMO #384 70 AMX 360 4-speed (since 1981)

mbwicz Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Joined: Feb/20/2019 Location: Buffalo, NY Status: Offline Points: 1991	Post Options Post Reply Quote mbwicz Report Post Thanks(0) Quote Reply Posted: Nov/11/2019 at 8:35am
	I'm not that familiar with details and options on the AMX, but is there an option of adding a power booster to the drum setup? If the car stops fine, but requires a lot of pedal effort, then maybe a power booster would help out? This may also require a different master cylinder. My experience (years ago) is that drums stop fine when they are adjusted properly. But if they get hot (like living in a mountanous area) or the adjusters freeze up, they aren't confidence inspiring. So if this is a cruiser, maybe power drums are an idea. If its mostly original, you have the constraints of the 14x6 wheels and tires that limit how quickly you can stop as well.
	1970 AMX, one step forward, one step back. Both steps cost time and money.

Red Devil Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Jul/10/2007 Location: Canada Status: Offline Points: 1743	Post Options Post Reply Quote Red Devil Report Post Thanks(0) Quote Reply Posted: Nov/11/2019 at 11:44am
	I have factory braking tests from '72 and '73, included with the owner's manual, that show results under controlled conditions with manual, power, drums and discs on various models. Interestingly, some models with manual drums stopped as short or shorter than those with power discs. Power brakes require less leg effort for normal stops. They do not increase at-the-limit braking capacity - pedal ratio is reduced with power brakes so the net braking force at the limit is virtually the same as manual brakes. But your leg will appreciate the reduced effort of power brakes in normal driving. At the limit, tires and road conditions are typically the limiting factors and you can skid the tires with either drums or discs. Issue with many older cars is getting good quality pads and shoes. High-performance pads and shoes are available for most cars with higher CoF and higher temperature range (e.g. Porterfield R4-S) if you're wanting improved braking force and improved fade resistance - people often don't recognize that pad/shoe compound is critical to good braking performance. Years ago you could also get the shoes arced to the drum for quick break in. Few places do that anymore. So my 2 cents, keep the drums, rebuild and adjust them properly, get good shoes (Porterfield R4-S are about $100 a set ... considerably less than most disc upgrades). If you're planning on canyon carving or wanting less leg effort, convert to power discs. https://www.porterfield-brakes.com/images/portstrt2008_11_06_02_45_30.pdf Hope this helps, RD.

Trader Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: May/15/2018 Location: Ontario Status: Offline Points: 6881	Post Options Post Reply Quote Trader Report Post Thanks(0) Quote Reply Posted: Nov/11/2019 at 11:46am
	If it's that original, I'd tend to want to keep it that way myself. But it would be the summer cruiser and show car, not a city driver. Stating this, the braking distance of manual vs power brakes is no different from a physics point of view. From driver effort, that is different. It's the 290 manual 4 speed I'm guessing, so it's not going for drag racing as is. Does it have 1-3/4" or 2-1/2" width shoes? If it has the 1-3/4" front shoes, switching to the 2-1/2" (front drums as well) will give you 40% more stopping power - without changing original as there was no code designation for this that I know of. You would likely need a donor big car - Ambassador.. to do this. Before changing to power brakes, this is what I would look at. If it has the 2-1/2" brakes and your still not happy, power booster would be next, but you need the power brake pedal and rod also.

401MATCOUPE Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: May/20/2010 Location: Salisbury, MD Status: Offline Points: 5367	Post Options Post Reply Quote 401MATCOUPE Report Post Thanks(0) Quote Reply Posted: Nov/11/2019 at 11:47am
	I would just leave the manual drums, but refresh the wheel cylinder seals, the kits are cheap and then you know what you have.......
	Ross K. Peterson 68X,GoPac,343,AT,52A(1stCar) 68X,GoPac,390,4sp,52A 69X,GoPac,390,4sp,64A 70X,GoPac,390,4sp,87A,8 70X,GoPac,390,4sp,BBO,8 70 Jav SST,390,AT,BSO 74MatX,401,AT,Prototype 74MatX,401,AT

BU1 Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Aug/11/2016 Location: MN Status: Offline Points: 2012	Post Options Post Reply Quote BU1 Report Post Thanks(0) Quote Reply Posted: Nov/11/2019 at 2:18pm
	Thank you all! The 2 1/2" brake conversion sounds interesting. The prior brake job included master cylinder, 4 wheel cylinders, front seals, hardware kits, adjusters, shoes, drums were turned. I will go back through everything when I get to that point to make sure everything is still up to par. I want to replace all the brake lines and hoses too. This will be less work than doing a conversion now, it will save time and expense. Plus the car will stay true to it's roots. Thanks again. I appreciate all the help from this forum.
	AMO #2726 #1 1968 AMX Rally Green 343 Z code 4spd since 1975 #02642 #2 1968 AMX Rally Green 290 N code 4spd since 2019 #02959

amx007 Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Joined: Dec/31/2008 Location: stone pk Status: Offline Points: 750	Post Options Post Reply Quote amx007 Report Post Thanks(0) Quote Reply Posted: Nov/11/2019 at 5:37pm
	I am restoring my 68 290 4 speed amx all drum I like that option of 2 1/2” shoes thanx for info
	dream red white and blue 1968 Chicago auto show amx 290 4 speed 1969 driver Amx 290 auto