Thinking about replacing my M/C which one is the best?

[brads70]

I asked the e-bay seller (Dr. Diff?) about this recomondation and here is his reply. What do you all think? Autoxcuda sounds like the kit you have?

Dear doctordiff1,

Hi I'm a member on Cuda-Challenger.com and your part was suggested to me by another member.I just bought a 70 Challenger with a manual(I think) drum master (it has a bolt on cover). The car has been converted to disc on the front ( bigger stock 11.75 rotors -73 spindles) small drums on the back, and am in need of a master for the disc's I'm replacing all the wheel cyl, and calipers so I thought I'd do the master as well. My question is what size of bore do I need for a master cyl.? The does NOT have power brakes. I only want to do this once! With this size how would the pedal feel be? How would it work with my set up?
I guess with your set up I would have to cut off the fittings and refare with your supplied fittings?
Thanks Brad

Hi Brad,

Normally, I recommend my 1 1/32" bore master cylinder package for that application, unless you are running '73-'75 A-body calipers. This master does not require changins the fittings.

It comes down to personal preferance, however. The 15/16" master will yield a softer pedal with a longer stroke. The 1 1/32" bore version results in a firm pedal with short stroke, but less stopping power.

I will list the 1 1/32" masters on eBay as soon as I get them back in stock next week.

Thanks,

Cass (406)883-4772

[brads70]

I asked the e-bay seller (Dr. Diff?) about this recomondation and here is his reply. What do you all think? Autoxcuda sounds like the kit you have?

Dear doctordiff1,

Hi I'm a member on Cuda-Challenger.com and your part was suggested to me by another member.I just bought a 70 Challenger with a manual(I think) drum master (it has a bolt on cover). The car has been converted to disc on the front ( bigger stock 11.75 rotors -73 spindles) small drums on the back, and am in need of a master for the disc's I'm replacing all the wheel cyl, and calipers so I thought I'd do the master as well. My question is what size of bore do I need for a master cyl.? The does NOT have power brakes. I only want to do this once! With this size how would the pedal feel be? How would it work with my set up?
I guess with your set up I would have to cut off the fittings and refare with your supplied fittings?
Thanks Brad

Hi Brad,

Normally, I recommend my 1 1/32" bore master cylinder package for that application, unless you are running '73-'75 A-body calipers. This master does not require changins the fittings.

It comes down to personal preferance, however. The 15/16" master will yield a softer pedal with a longer stroke. The 1 1/32" bore version results in a firm pedal with short stroke, but less stopping power.

I will list the 1 1/32" masters on eBay as soon as I get them back in stock next week.

Thanks,

Cass (406)883-4772

Anyone else have the set up like Autoxcuda? I'm not sure what would be best for bore sizes? 15/16" or 1 1/32"? Answers differ depending on whom I talk to? I'm thinking the 15/16 would give me more brake ?
Can anyone post a link to another post if this has been covered in the past?

[autoxcuda]

Anyone else have the set up like Autoxcuda? I'm not sure what would be best for bore sizes? 15/16" or 1 1/32"? Answers differ depending on whom I talk to? I'm thinking the 15/16 would give me more brake ?
Can anyone post a link to another post if this has been covered in the past?

I think you need to clarify with Dr Diff what he means by stopping power.  Is he saying the 15/16 will stop the car in a shorter distance or it will take more pedal effort (power) to stop the same distance as the smaller 15/16 unit.

I can lock of the brake at any time. It just takes more effort.

Note: I have the pin type calipers. I don't know if the slider type calipers have the same piston bore. I know there are two different sizes of slider caliper bores. And I don't remember how either compares to the pin type bore.

There was a guy on Moparts with a 70 Dart with 11.75 rotors and bought a E-berg 1 1/8 bore master and felt it took way to much pedal force with manual brakes. I assume somedaysoon had the similar results?

The guy with the 70 Dart bought a Dr Diff 15/16" master and was happy with the pedal effort. But he did note the pedal travel definitely went up.

I bet the 1 1/8 would work fine with power/hydroboost.

My 1 1/32 seemed to work ok on Thursday, but I only got one session on the track. Dr Diff mentioned a 1" master would be nice manual setup. But I think they don't make that in aluminum or something??

[brads70]

I think you need to clarify with Dr Diff what he means by stopping power.  Is he saying the 15/16 will stop the car in a shorter distance or it will take more pedal effort (power) to stop the same distance as the smaller 15/16 unit.

I can lock of the brake at any time. It just takes more effort.

Note: I have the pin type calipers. I don't know if the slider type calipers have the same piston bore. I know there are two different sizes of slider caliper bores. And I don't remember how either compares to the pin type bore.

There was a guy on Moparts with a 70 Dart with 11.75 rotors and bought a E-berg 1 1/8 bore master and felt it took way to much pedal force with manual brakes. I assume somedaysoon had the similar results?

The guy with the 70 Dart bought a Dr Diff 15/16" master and was happy with the pedal effort. But he did note the pedal travel definitely went up.

I bet the 1 1/8 would work fine with power/hydroboost.

My 1 1/32 seemed to work ok on Thursday, but I only got one session on the track. Dr Diff mentioned a 1" master would be nice manual setup. But I think they don't make that in aluminum or something??

I too have the pin style calipers. Sounds like identical set ups! I guess I'll pull the trigger on the 1 1/32 set up like you have when he lists them! That's what I love about this site,honest un-biased opinions ! Were does he say about the 1" master? That sounds like a good "middle ground" ?
Thanks! Brad

[brads70]

I just bought the 1 1/32" master cyl set up.  Thanks Quapman and Autoxcuda for your advice! I won't have it running till the spring so I'll post then what it's like.

[autoxcuda]

I just bought the 1 1/32" master cyl set up.  Thanks Quapman and Autoxcuda for your advice! I won't have it running till the spring so I'll post then what it's like.

Was that a cast iron or aluminum housing master?

[brads70]

Was that a cast iron or aluminum housing master?

Aluminum
http://cgi.ebay.ca/ws/eBayISAPI.dll?ViewItem&item=180456238598&ssPageName=STRK:MEWNX:IT

[quapman]

Brad, does this one work with the stock fittings or will you have to change them or the lines?

[brads70]

Brad, does this one work with the stock fittings or will you have to change them or the lines?

 He says stock fittings

[brads70]

My new M/C just showed up today. Hey Pete it looks like the same one you offered? I got out the verniers and measured the bore. If you measure at the end around the spring clip the bore does measure a little over 1 1/8 ,so I removed the clip and pulled out the piston enough to measure and it is 1 1/32. So I'm sure it is the exact same as yours! Oh well someone else will most likely need it someday?
Thanks anyhow! Now I just need some warmer weather to work on the car. I'm getting a big pile of parts to put on the car again!

[shadango]

Did you install this yet?

I am in the same boat....was gonna go with the autozone listing for a 72 with disk brakes....

I am running a setup like yours...11.75 rotors...but I have the slider calipers from a 80 NYer.

Wondering which way to go.

[brads70]

Did you install this yet?

I am in the same boat....was gonna go with the autozone listing for a 72 with disk brakes....

I am running a setup like yours...11.75 rotors...but I have the slider calipers from a 80 NYer.

Wondering which way to go.

Nope not yet, busy and too cold,LOL I'll post when I get it installed though!

[shadango]

Or 5 months later when super cheap Auto Zone crap breaks!

M/C I would buy a unit that is brand new, casting-everything. Not some 40 year old worn unit with new seals done in Mexico. $100 seems alot compare to $20 with a lifetime warranty but if the M/C goes out on a high speed stop and you wipe your car out, Auto Zone isn't going to give you nothing but another half worn out $20 M/C

Where are the new ones made?   

I have been running a Autozone "fenco" unit....non power, drum front....and had no issues over the summer and I stomped them pretty hard a few times.....not to mention trying to hold the car at a light at the bottom of a long, fast downhill stretch....(I will so glad to have the disks on there!).....

They offer a new Fenco for those with power front disks...for us non-power disk folks there is only a rebuilt....but they say its resleeved, never honed....new seals/orings and multi-stage computer tested .

I havent gotten the MC for the new disk setup yet...that is where I am now...

For the Fenco, I would be in it for about $43 and tax and not have to worry about changing the fittings on the lines, etc....and it would look more or less correct.....it is a 1 1/32" bore too.

The mopar one you are talking about has the reservoir which is nice and neater what with the caps....

Dunno.....who is to say that the build quality there is any better?

[shadango]

Been thinking on this and decided to so some more looking around.

I am using the 80 NYer front slider calipers and 11.75 rotors....

For the 80 NYer, Autozone lists a brand new Fenco master cylinder, complete, for  $38 and tax...so about $40 out the door.  Looks exactly like the one you guys are talking about at Dr Diff. It has the same size fiitings and the same bore measurement. The adaptor plate is available from several places for around $35-40 plus shipping.

Now , I dont know if Autozone's unit is aluminum or cast iron......or if the Autozone one will be bored for the manual brake rod....What is the benefit of the aluminum version over the cast if there were both aside from slight weight savings? 

My concern was that the aluminum would be easier to strip when installing the brake lines....also, the MCs from autozone would have a lifetime warranty.....whereas the Dr Diff unit doesnt.....

My guess? Dr. Diff is selling the same parts we can get as-is or at the most boring the piston for the manual rod....whihI cant do so it made the decision for me. I didnt feel like buying the Autozone one to find it needed bored.

Also my brain hurt from thinking too damn much ...   ......So I sprung for this kit from Dr. Diff... $113 shipped.

At least I know the bore is the same as for what was used on both my 72 drum system and the 80 NYer system. 

I did come across this tidbit in the Moparaction brake conversion article:

"In the mid-1970s, Chrysler eliminated the rear brake residual pressure valve from the master cylinder. Its function was to prevent any air from sneaking into the system via the rear wheel cylinder cups. In its place, Chrysler substituted "expanders" in the rear wheel cylinders. (Expanders are dish-shaped steel inserts that exert outward pressure on the cups.) If you should decide to use a master cylinder from a 1975-up car, be sure you have the expanders in your rear wheel cylinders. For at least 20 years they have been universal in all replacement wheel cylinders and rebuild kits."

Hmmmm.....interesting.  Guess the only way to know is to tear apart the rear wheel cylinders?

[shadango]

My new M/C just showed up today. Hey Pete it looks like the same one you offered? I got out the verniers and measured the bore. If you measure at the end around the spring clip the bore does measure a little over 1 1/8 ,so I removed the clip and pulled out the piston enough to measure and it is 1 1/32. So I'm sure it is the exact same as yours! Oh well someone else will most likely need it someday?
Thanks anyhow! Now I just need some warmer weather to work on the car. I'm getting a big pile of parts to put on the car again!

Just got mine in the mail today.

I do have to say that Dr Diff is FAST as far as shipping.  No fancy packing or anything, just the part in a zip lock bag (which doesnt close..LOL).  Thats cool......money spent on fancy packing ends up coming out of the consumers pocket.

The master cylinder is marked "Sanyco"....chinese I would assume.

Looks to be a decent unit....guess we'll see if it stops the car...LOL

Hey, did yours come with mounting studs?  As I recall, the stock MC has studs in it that go thru the firewall.   

Many if not all of the adaptor plates I saw for sale had studs with them.  I just assumed thios one would I guess.