• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

Questions about the stock 4-wheel drum brakes

moparedtn

moparedtn

I got your Staff Member riiiight heeeere...
FBBO Gold Member
Local time
8:18 AM
Joined
May 14, 2011
Messages
17,202
Reaction score
32,325
Location
On the Ridge, TN
Ladies and gentlemen,
I am going to be overhauling/replacing the stock 11" manual drum brake
system on my 1968 Plymouth GTX soon; the decision has been made to
stay with all drums, 11 x 2.5 rear and 11 x 3 front, just as the car was built
with.
"Fred" had linings and master cylinder replaced a handful of years ago, but
the pedal has been spongy regardless of number of times/method employed
to bleed them - and the linings available from the parts store might as well
be cardboard, as little bite as they provide.

I will be replacing drums, shoes, soft lines, hardware and master cylinder,
retaining only the hard lines on the car, since they're all new replacements
and currently leak-free. Wheel cylinders will also be replaced with new.
(The decision has been made to forego any disc brake "conversions").

Now for the questions. I'll be most interested in hearing from those who have
actually bought and installed the same stuff I'll be after:

1. The factory drums are the finned type in the rear (11" x 2.5") and non-finned
front (11" x 3") with a spring around them, correct?
Further, we can't use c-body 11x2.5 rear drums because of the extra "hooding"
on them, yes?
Are the currently available "Bendix" new finned rear drums worth a spit?
Where would one find the springs for the front drums new?

2. What year was asbestos eliminated from brake linings (and if known, what were
the part numbers for "the good stuff")? I recall even "back in the day" the
manufacturers tried going with sintered metallic linings in an effort to replicate the
stopping ability of the former asbestos linings...with dubious results.
Must I use the linings available from musclecarbrakes.com to get shoes that
have actual "bite" like the factory linings did?

3. If I find new, but very aged components (such as wheel cylinders, master
cylinder, etc.), do they deteriorate on the shelf to a point where they are no
longer trustworthy?
My priority will be to find components Made in the USA (or yes, Canada);
no Chinesium parts will be used, period.

4. Is the master cylinder for all drums the one with a 1" bore? Is there any
difference amongst those available with that bore (identifiable by various
different lids, example)?
Is the Bendix-branded reproduction currently available from many outlets
Chinese? Is it worth a spit? Anyone actually using one of them?

Given my situation, I want to do this once and do it properly. Given my finances,
I will do my usual due diligence to seek out the "deals" on these components,
of course - but there will be no cheap junk used if at all possible.

Thanks in Advance!
 
All I can say is CCJ. I do not care what vendor most are selling CCJ. Look hard and read between the lines.
 
pnora said:
All I can say is CCJ. I do not care what vendor most are selling CCJ. Look hard and read between the lines.
Click to expand...
There won't be any of that if at all possible - I'm quite persistent in my parts hunting diligence. :)
 
Ed, @68RRLL1 had some 11X3. I don't know if they are still available, but aren't marked sold.
 
I would recommend adding self adjusters if you don't have them. Especially on the front.
 
I'm pretty sure the master cylinder has a 1" bore. I sent my master cylinder out to Brake & Equipment Warehouse in Minneapolis, MN and they re-sleeved it with a stainless steel sleeve. It is working fine.
 
Bob Sawyer said:
I'm pretty sure the master cylinder has a 1" bore. I sent my master cylinder out to Brake & Equipment Warehouse in Minneapolis, MN and they re-sleeved it with a stainless steel sleeve. It is working fine.
Click to expand...
Would you happen to have a pic of your original m/c?
 
20190919_174806.jpg

68 Coronet R/T original M/C
20200511_152217.jpg

67 GTX original M/C
20200511_152312.jpg

67 Hemi GTX M/C
All 11" drum brakes. I'm not 100% sure the 68 R/T is original, but they work great.
 
I'm thinking they're all the same bore - and Fred has the same lid type as your '68 - but I think the
other two are indicative of what he should have had originally?

I have another question to add to the list - does anyone reproduce the spring that goes around the
front drums?
 
moparedtn said:
I'm thinking they're all the same bore - and Fred has the same lid type as your '68 - but I think the
other two are indicative of what he should have had originally?

I have another question to add to the list - does anyone reproduce the spring that goes around the
front drums?
Click to expand...
@mobileparts
 
Ed, Why do you think you need new drums, as long as the pads aren't run down to metal they usually last almost forever?
Does your pedal pulsate?
I think in your case it would be wise to consider doing things in stages instead of wholesale changes.
I know you end up doing things like bleeding more than once but the benefit is you can learn which change made a difference.
I would suggest starting with pads, then master, and probably soft lines and wheel cylinders at the same time.
You might want to consider braided flexible lines as they offer a more rigid housing and yield a hard pedal.
Keep us posted on your progress.
 
Don Frelier said:
Ed, Why do you think you need new drums, as long as the pads aren't run down to metal they usually last almost forever?
Does your pedal pulsate?
I think in your case it would be wise to consider doing things in stages instead of wholesale changes.
I know you end up doing things like bleeding more than once but the benefit is you can learn which change made a difference.
I would suggest starting with pads, then master, and probably soft lines and wheel cylinders at the same time.
You might want to consider braided flexible lines as they offer a more rigid housing and yield a hard pedal.
Keep us posted on your progress.
Click to expand...
Yessir, after doing my usual middle of the night due diligence online (seeing what's out there, etc.)
the game plan is forming up a bit more clearly now.

I have the four drums on the car now, condition unknown - but no harmonics or grating sounds to speak of.
I have two additional used drums off a Road Runner I got cheap off a fella a couple years ago that look like
they have decent meat left on them, too.
I figure when I have Fred up on all jackstands, I'll take all six drums down to the machine shop and we'll
see about picking out the best four, then turning them pretty again.

Wheel cylinders - seems NAPA carries Raybestos new ones and at least in the pictures, they say MADE IN USA,
so that's fine too - and quite reasonably priced to boot.
They will all be replaced outright.

There's all kinds of NOS shoes out there for the expected prices - but I don't want any of the "2nd generation"
ones that were produced after asbestos was outlawed. I remember those well and they just don't bite right
for me.
Professor Ehrenberg has some metallic ones that look healthy and he says they're made by an OEM USA
producer, might check into those - or I can always fetch the ones @Dennis H runs from musclecarbrakes.com.

The metal lines on the car are all pretty much new, so the flex lines are all I'm after as you say.
I will not accept Chinese stuff from any of the parts stores for those - they'll have to be the good stuff.

I'll save the master cylinder for last, but it's gonna get gone too. Pedal is there, but crappy as hell....
Thanks!
Ed
 
Bob Sawyer said:
View attachment 1087166
Click to expand...
Yep, that's what I thought (and @Jerry Hall said too). Mine is the flat plate with a bolt down the middle
cap type and it was new when I got Fred over a decade ago - but no matter how much bleeding is
done, it's always felt crappy, so I don't trust it. It'll get gone eventually.
Wonder if that reproduction Bendix one everyone is selling is any good? Gotta be Chinese, I'd thnk?
 
Ed, spongy even after bleeding sounds like a M/C issue to me. Brake shoes, and wheel cylinders will not cause that. Flex lines bad in the front will cause severe pulling to one side or the other, and in the rear will cause a rock hard petal. Petal feel and/or height comes from the rear brakes. I would ofcourse pull all the drums and inspect shoes, wheel cylinders, and the springs for wear or leaks, but the M/C and rear brake adjustment are responsible for petal feel. IMO I would take a serious look and/or rebuild/replace the M/C first not last. May save you some $$$.
 
And the Master is the easiest thing to replace.
Bench bleed leave the lines just a bit loose pump once or twice and tighten.
Just watch where that fluid goes of course.
I usually don't even need to bleed the system.
 
I just purchased both Raybestos and AC/Delco wheel cylinders for my ABody, all made in China. Don't get your hopes up per post #15 that NAPA carries USA made components. If they do, please let me know. You can easily rebuild wheel cylinders, but then again, where is the rebuild kit manufactured?
 
Jerry Hall said:
Ed, spongy even after bleeding sounds like a M/C issue to me. Brake shoes, and wheel cylinders will not cause that. Flex lines bad in the front will cause severe pulling to one side or the other, and in the rear will cause a rock hard petal. Petal feel and/or height comes from the rear brakes. I would ofcourse pull all the drums and inspect shoes, wheel cylinders, and the springs for wear or leaks, but the M/C and rear brake adjustment are responsible for petal feel. IMO I would take a serious look and/or rebuild/replace the M/C first not last. May save you some $$$.
Click to expand...
Yep, why I keep asking questions about the master cylinder. It may well be the newest component of this system -
but I don't trust it, after repeated bleedings and adjustments of brakes. This is not the pedal feel I recall from old
days on these cars...only question is, if I don't bite the bullet on one of those repro masters floating around the
vendors (China) right now, what the heck else is there? I didn't see much else digging around.


Don Frelier said:
And the Master is the easiest thing to replace.
Bench bleed leave the lines just a bit loose pump once or twice and tighten.
Just watch where that fluid goes of course.
I usually don't even need to bleed the system.
Click to expand...
Speak for yourself, Don. :)
Getting under the dash is probably the hardest thing for me, hands down - then to get at the bolts under there?
No walk in the park for my decrepit old arse.
Why in the hell could they not have done "studs out" to mount the m/c? Never understood that.
 
You must log in or register to reply here.

Similar threads

S
brake drum sizing
Replies
7
Views
418
Scott Kiger
Scott Kiger
A
Aftermarket wheel cylinders
Replies
8
Views
455
mobileparts
M
D
dart master cylinder
Replies
3
Views
271
matthon
matthon
mitchs66
Manual single brake master cyl. to dual power 4 wheel drum
Replies
4
Views
912
R/T Boy 67
R
Jimclo2002
70 super bee brake problems
Replies
16
Views
2K
Dartman72
D
Auto Transport Service
Back
Top