Disc brake conversion using stock drum hubs and spindles 2 piston, 4 piston or 6

[Dino]

Be Advised-

The 13.2 front conversion DO NOT clear 17 inch MB Old School wheels. I will post pictures later on today.

That's bad news, I was gonna get a set of those for mine as well. What's the next size down?

[Mike DC]

Be Advised-

The 13.2 front conversion DO NOT clear 17 inch MB Old School wheels. I will post pictures later on today.

That brings the options down to, what, 11.5" inch rotors?  On 17" wheels?  


Screw that.  How far are the 13.2's from clearing?  Could you grind the calipers enough?

Or grind some meat off the perimeter of the 13.2" rotors, and use a one-off caliper bracket that positions the caliper a bit closer in? (Hey, some 4x4 guys will grind 1/4" off the ring gear of a huge Dana axle just for clearance.) 

[invincibleextremes]

Next size down is 12.4 using the exact same caliper on a different mount.  Wondering if its the straight spokes or the wheel that doesnt clear?

[Ryan.C]

Next size down is 12.4 using the exact same caliper on a different mount.  Wondering if its the straight spokes or the wheel that doesnt clear?

It is the wheel that does not clear. The caliper gets larger towards the rear and the inside diameter of the wheel gets smaller towards the spokes. As the two come together it makes contact. I got out the die grinder and have taken off a substantial amount of material off of the caliper and it looks like with a little more grinding I can get the clearance necessary however, I think I will end up running a 1/4 wheel spacer to clear the caliper bracket once I get the wheel a little closer to where it needs to be. I will see how much material needs to come off before making a determination if this is safe. I figure I am in this deep I might as well keep going just to see.

I got called into work today and am unable to post pics. I will see what I can do tonight.

[invincibleextremes]

Oh ok.  You can reuse those calipers, if you get the 2005-2010 mounts and a set of 12.4 rotors... that'd be a lot safer than using a 1/4 spacer...

[Mike DC]

           
Oh yeah, I had forgotten about the 12.4" rotors.  

That makes it feasible to step down a notch.  

--------------------------


I'm kinda curious whether the basic Mustang front calipers (2-piston alloy) could be made to grab some kind of 11" disc inside an old-school 15" wheel.  With little vintage wheels the shallow depth of the "hat" on modern rotors begins to pose a problem.  

[invincibleextremes]

The 12.4 setup is actually easier to get ahold of,

[funknut]

Has anyone completed the front swap and replaced the lug studs?  The shoulder/knurl on the stock drum studs interferes with the discs, and ideally I'd like to get some longer studs because of the added width of the disc.  Not many threads left to bite.  I can clearance the discs to get them to mate flat to the hubs, but then I'd have to do it each time I replace the rotors (not often), and the studs would still be shorter than I like.

I measured the hubs and I got 0.500" knurl length (width of the hub) and knurl diameter of 0.625".

The closest I can find is this one:

http://www.dormanproducts.com/itemdetail.aspx?ProductID=20167&SEName=610-368

If you look at the specifications tab it's a knurl diameter of 0.627" and a shoulder length of 0.513".  Total length is longer than stock at 1.969"

It looks like ARP sells some that are 0.625" w/ 0.400" knurl length but they are 3.5" long and I don't really need/want them that long.

https://www.summitracing.com/parts/arp-100-7703

Seems my options are to try the Dormans or get the ARP studs and cut them down.  Have any of you completed the conversion and how have you addressed this issue?

Thanks,

Clay

[invincibleextremes]

Moser sells studs in .625 knurl.  1/2-20.

[funknut]

Cool, I thought it was a big deal to cut down wheel studs but looks like it's fairly common practice.

[funknut]

Progress!  Finally making some decent progress on the brakes.  I'm currently held up on the brake booster but should have that sorted early next week and then I'll be off for an alignment.

I went with the 13" Mustang GT brakes.  The calipers were taken off a new car, less than 10 miles on those.  I got a good deal on the rotors, too, so for around $400 including the brackets, I have front discs.  For anyone doing this conversion that has to buy caliper mounting bolts, I bought M12 x1.75 25mm grade 5 from Home Depot.





These are 18" x 8" AR Torq Thrust II with 4.5" backspacing and while there's plenty of room around the inner perimeter of the wheel, the spokes do contact the caliper.  It's really minor, I'm guessing less than 1/16".

There's plenty of meat on the calipers, so no worries there.  A few minutes with a grinder and a flap disc and I'll be good to go! 

[invincibleextremes]

The 12.4 inch kit seams to be the best comprisemise in fit and money.  The 13.2 setup only clears certain wheels it seams.

[invincibleextremes]

Got another batch of rears as well as the spacers needed to run brembo brakes getting cut.  Should be ready to go in a couple weeks for those who wanted the 4 wheel disc adapters.

[funknut]

Trying to finish things up.  Just got most of the new brake lines in.  How are you all routing the lines from the calipers to the hard line?  

The calipers seem to want to run the hoses up towards the UCA.

Anyone got pics?

[Ryan.C]

Trying to finish things up.  Just got most of the new brake lines in.  How are you all routing the lines from the calipers to the hard line?  

The calipers seem to want to run the hoses up towards the UCA.

Anyone got pics?

I flipped my calipers left to right and right to left. I also used the banjo bolt that came with the mustang caliper to mount my original Chrysler disc brake hoses. If someone has a better way I am all ears as I am not exactly happy with the way mine are currently routed either.

[invincibleextremes]

Have another batch ready to go if anyone is interested. 

[68ChargerJMP]

Are you guys having to use longer lower spindle bolts?  As a rule of thumb you need at least the nut's thickness of bolt sticking through, mine sits about flush. Are you still using the castle nut with cotter pin or did you go Grade 8 and locknut?

[funknut]

I got all new grade 8 hardware and locknuts for the spindles.  It was a pain to find locally so I ordered them from https://www.fmwfasteners.com.  Cost me about $25 shipped.  No idea if I got a good deal or not. 

5/8"x18 -3"
7/16"x20 -2"

[68ChargerJMP]

Thanks....I had to order some as well. Not too common of a size locally for me either.

[68ChargerJMP]

Also, what wheel studs did you decide to go with? Are you using the ones you listed funknut? How much longer do they need to be for aftermarket alumninum wheels?

[funknut]

Also, what wheel studs did you decide to go with? Are you using the ones you listed funknut? How much longer do they need to be for aftermarket alumninum wheels?

I ended up going with the ARP studs and cut them down so I could use an acorn style lug nut with them.  I didn't really like the look of the long studs sticking out, plus the ARP studs are a gold color which didn't look right to me.  I measured quite a bit before I cut, and the aluminum wheel is definitely thicker than the steel mag 500s I had on before.

This is what worked great for me: I drilled a hole in a 2x4, pushed the stud through and tightened it down with a short open ended wheel lug.  Then I just cut the stud flush with the top of the lug using an angle grinder and cutoff wheel.  This left me with plenty of threads.  If you go this route I highly recommend hitting it with a flap wheel to take some of the sharp edges off.  I was in a hurry and just installed them.  Trying to clean them up after they're installed is a pain.

[invincibleextremes]

Heads up!  The 11 inch drums have a different hub that has a more inboard mounting face and therefore does not work with this setup.  This setup is properly spaced for the cheaper 10 inch drum hubs... so yeah.  The one and only guy I knew who used the setup on his 11 inch drum hubs had to go out and get some b body 10 inch hubs...

[68ChargerJMP]

Mine were 11" drums.....mine seemed to fit.  Where is the problem exactly?

[68ChargerJMP]

Maybe I don't have 11" drums....they are not finned. I read the 11" drums were finned...My build sheet calls out HD brakes, I guess I thought that meant the bigger 11" brakes.....

[BLK 68 R/T]

Trying to finish things up.  Just got most of the new brake lines in.  How are you all routing the lines from the calipers to the hard line?  

The calipers seem to want to run the hoses up towards the UCA.

Anyone got pics?

I flipped my calipers left to right and right to left. I also used the banjo bolt that came with the mustang caliper to mount my original Chrysler disc brake hoses. If someone has a better way I am all ears as I am not exactly happy with the way mine are currently routed either.

Had the same problem as you, the soft lines that came with the kit are made for front mounted calipers and just would not work, no matter how I tried them. I went with the 15" versions from Dr. Diff below. Problem solved.

http://www.doctordiff.com/stainless-front-brake-flex-hose-kit.html