Rehauling e-body HD drum brakes

[Dmod1974]

Maybe I missed it, but where did all of the brake fluid go?  Your shoes were not that worn and the master cylinder was dry...  and brake fluid doesn't evaporate.  Are you 100% sure the lines, hoses, and wheel cylinders are ok?  You likely have a leak somewhere in the rear brake circuit.

[kawahonda]

Have not found obvious leak yet...

It could be the MC just straight up failed too.

I don't believe there would be any DOT3 left when I'm done....I'm flushing hard lines with brake cleaner. Soft lines are being replaced.

[kawahonda]

I got the car off all-four today and removed the rear drums.

I inspected the hardline some more. While the front I am pretty happy with, the section that runs near the rear axle could definitely look better. A little rust and dirt. Mostly just dirt/undercoating. All this seems limited only to the "spring" that surrounds the line, so I'll liekly just leave it be. Rest of the lines from the outside look great (and the insides look great). I figured if I'm this far, what's another $150 to replace all hard-lines in the car with stainless?

I also found another brand of drum hardware that matches better as far as the spring lengths are concerned (for the rears). It even includes the bottom spring which I had to reuse on my fronts--I will buy another set and throw them on the fronts as well.

If I was in a rush/hurry, I definitely wouldn't replace the hardlines, but because i'm likely going to be in "machine shop hell" for another week or two, MIGHT put the little extra effort and just replace all the lines with stainless, and let it last a lifetime. Then again...if DOT 5 is going in....

That's about it for me today. The fronts are done. I will order DOT 5 on Amazon.

EDIT: On second thought, I think I'm going to leave the hard-lines in-tact. The car is relatively rust free, and the lines look great. They have the factory undercoating on them, and I really havent' seen any signs of rust inside. I was able to flush them ALL really good today.

I'm really excited to try out the car once I'm done. I've always thought it stopped pretty well (except the last trip home), but it will be nice to see what a fresh set of HD drums perform like on a Challenger.

[MoparLeo]

Brake lines fail from the inside out. Like a radiator hose. No way to really test a line for internal pitting/wall thickness. Smarter to replace. The factory lines have lasted over 40 years with no maintenance. Stay away from S/S lines. The flares are very difficult to seal. They are not very malleable.  Obviously use flare nut wrenches on all brake, fuel line fittings.

[kawahonda]

My friends (who have tons of experience and are much older than me) are asking me why fuss around with machine shops to transfer the hub. They told me to bring them on by (they both have shop presses)--and they even have digital wheel balancing/monting machines which is pretty cool. Press them out, press them back in.

What I'll do today is I'll clean the back side of both hubs and get them soaking in PB blaster.

I thought long and hard about buying new studs, but it will be more trouble than it's worth to buy new studs. My challenger has the infamous LH + RH studs. LH studs are impossible to find, which means I'd need to use RH. That means my driver's rear will be mis-matched compared to the rest. The big thing is due to my wheels, I have to order special ET conical nuts that will need to be lathed to the proper size, such as I've already done with the set I have now. All of these is the reason why I will try to reuse the studs. They are in good shape and not striped out. As long as they go in there and seat tightly, then should be good to go. Something I may consider doing in the distant (like, really distant future) is to replace all studs with RH, but for now, it's scope/project/money creep.

I did order OE steel brake lines last night. For $150 shipped, cannot complain. I'm hoping replacing the F to R brake light is about as easy as it was to replace the fuel line. All the other lines should be really simple to do, the next difficult one being the passenger-side front line, but that doesn't look difficult. The others are dead-stupid easy.

I'll cut open the current line once I get it out to see if I was right. My hypothesis is that the brake line is fine to reuse with little to no corrosion.

[dodj]

I think you will be happy you went with OE type brake lines rather than SS. 

[kawahonda]

I'm being told that if I'm not replacing the studs, then there is no point to push the studs out. Just push the hub out and push the hub into the new one....

It's that easy?

But looking at them, it looks like they are swedged (like MoparLeo said), so it almost seems like you kinda have to press the studs out first, unless you're really lucky.

I'd bet you anything these are the original drums. The overspray and swedging look factory. The front drums have that "spring" that runs around the outside (guessing I should junk that?)?

I do have some options, and none are extremely pleasing.

1) Order 10 new RH studs and just have new ones pressed in. Convert Driver's front to RH lug news (means ordering 5 new ET conical lugs) and get those lathed to spec. Still requires a machine shop. Kinda wonky still having the driver's rear studs be the only LH studs left on the car, but I guess that's minor.   Do new studs get "swedged" as well, or should them? Good shops may have a swedge cutter, so that it's likely studs can be reused?

2) Get the drums actually professional checked for roundness, and see if it's possible to just service them. I checked for thickness around the drum, but that likely isn't a full, professional check. I cannot find any printed "maximum diameter" spec on the drums, which really sucks, and may just rule that answer down hard.

3) Other options?

[kawahonda]

Another drum. And I've seen drums with no markings.
Terry

I'm afraid my drums may have no markings. That probably means I'm screwed if I ever cared to service them as there is no baseline spec for service? FSM only talks about out-of-round spec.

That is, unless all 11" front drums shared the same maximum diameter number....

[Bullitt-]

 Seems there is a tool called a swedge cutter

found this   https://www.forabodiesonly.com/mopar/threads/fixing-the-front-wheel-hub.357372/

Pricey little beast    https://goodson.com/products/swedge-tools

[RUNCHARGER]

I cut the swedges on my 70 D100 front drums carefully with a hole saw (obviously without the centering bit).

[kawahonda]

Do you guys think all 11" drum brakes have the same maximum thickness spec?

It seems like the easiest/fastest option would be to have the originals checked/machined, painted, and put back on. My drums have no markets. The FSM only mentions the out-of-roundness spec. I see that Terry posted an 11" drum that has 11.090". I noticed that the 10" drum he posted has a maximum diameter of 10.090". I'm noticing a pattern here...and if that pattern is consistant then I should take these in, give them the spec, and have them resurfaced if possible.

[MoparLeo]

Don't spend a dollar to save a dime. The band on the drum is a vibration damper. The drum could vibrate and make noises, like rubbing the edge of a crystal wine glass with a wet finger. Induce noisy vibrations. The swedging is done to clamp the drum firmly against the hub. Helps reduce brake vibrations. The studs cannot be swedged again. The max diameter is .060 on factory drums.  So 11.060 max on an 11" drum.  (Also kawahonda , the company doing your machine work should have the specs on what they work on, not relying on the person who brings the part in to supply that info. They are assuming liability  if the part ( in your case the brakes) fail due to machining past the manufacturers specs.) Because the manufacturers tended to use better/more materials it was generally assumed safe to go .090 if there were no marked specs on the drum, but the factory that sold the car sometimes stated their own recommendation for specs. There was no B.A.R. back then. This information is in your FSM if you have one. The professional brake guys will know what I mean when talking about Machine to specs vs. max. specs. This what the maximum that the part should be machined to so that is doesn't exceed the maximum spec. by the time the lining wears out. As you know the drum/rotor wears each time you brake, just like the shoes/pads do. Regarding the Factory Service Manual, Every one should have one and read it. Most questions on this forum can be answered just by reading their service manual. After all, that is what is was published for. If you look a the drum brake section you will find nice pictures of the complete assembly with details on part replacement and lubrication of the brake parts etc... Section 5 of the manual. If you don't have one, here is the link to download one.
http://www.mymopar.com/index.php?pid=109

[kawahonda]

It isn't in the specifications are (it should be), but I re-read the grinding recommendations section again (5-8), and it's there at the very end. .060" over the standard diameter is maximum. Interesting how Terry's drums state .090" as a max, but those may not be Mopar drums....

That's what I'll run with. 11.060" is the max. That's a good conservative number too according to Terry's photos. Let's see if we can keep these original drums in service instead of just immediately junking them....maybe necessary, but my not be necessary. This car either has 64,000 miles or 164,000 miles. I tend to believe in the former.

[kawahonda]

Dropped the front hubs off at an old-school wheel/tire shop. The shop looks like 1970 inside with wood grain everywhere. Guys were all in their 60s. Totally cool.

The guy measured them on the spot with a tool from the 70s and remarked "oh no problem, these can definitely be turned!"

Kinda thinking...is there any extra value with keeping my original rear drums and just bringing those along to get resurfaced and just throw all the new drums back in the attic for a later time?

[MoparLeo]

Original parts like brake drums are ok if the car is not going to be driven much. No collector value unless a rare survivor. Use the new parts for safety.