With the stock 4 cylinder running gear the 9" brakes are more than adequate if installed and maintained correctly. Poor brake raps on stock jeeps come from folks who either do not maintain them correctly or are comparing them against their new sedan.
Upgrading to a V6 is handled well with the 11" drum conversion. Running constant highway speeds with a stock 4 cyl and overdrive can benefit from the 11" brake conversion as well.
A front disc conversion is only needed if you move up in weight to the V8's and the speed runs above 60 regularly.
Stock 4.5 x 16 rims will have clearance problems with both upgrades. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
Joined: Apr 17, 2005 Posts: 891 Location: New Hampshire
Posted: Sun Jul 08, 2012 6:29 pm Post subject:
the stock rims will clear the 11 inch brakes without a problem. Disc breaks I am not sure about. My jeep is going to get the 11 inch brakes at some point. I like the security have the larger brakes along with the self adjusting of them.
Joined: Jun 09, 2011 Posts: 776 Location: Bellmore, NY
Posted: Thu Jul 12, 2012 9:14 pm Post subject:
"The Jeep Guy" sells powder coated, 11" drum brakes that swap right in on front and/or rear of my M38A1, and are very reasonably priced. I bought both, and the difference in stopping power is remarkable. http://www.the-jeep-guy.com/brakes.htm
I was initially going to switch to disc brakes, but they are a major headache-involving a new master cylinder, proportioning valve, wheel spacers, and maybe even new bake lines. With the original 4 cylinder, even with the overdrive I have installed on it, disc brakes would be overkill. _________________ 1952 M38A1
Marine core reinforced rear bumper, military transistorized turn signal upgrade, arctic heater, 11" drum brakes, 200L PTO winch, Huffy overdrive, deep water fording kit, RT 68 vehicle mounted radio, Trac Locs front and rear.
www.danhenk.com
Joined: Aug 31, 2010 Posts: 1741 Location: SO IDAHO
Posted: Thu Dec 05, 2013 3:08 pm Post subject:
kenc80 wrote:
Everyone is telling me to go to front disc.
Who is this "everyone" Ken?
I run a well maintained bone stock system on my M-38
with no complaints. Unless you're runnin a V-6 or V-8, or
upgrading to overdrive pushing speeds over 6omph
the stock setup when well maintained and adjusted
is more than adequate. My 2C.
BTW.. like what I saw in your foto album, looks like a
good, solid truck!! _________________ keep 'em rollin'
RICKG MC 51986 DOD 01-52, '50 CJ3a
Last edited by RICKG on Thu Dec 05, 2013 3:38 pm; edited 1 time in total
Rick, thanks. I appreciate the advice, my jeep buddies are mudders running modified CJ5's and 7's. Let the record state that I'm not a mudder and bought my A1 because I have a deep appreciation for military history!
I just want to be safe and it sounds like I'll be perfectly safe in the 9's as long as I'm under 55mph and am checking my fluid levels.
My friend has offered to teach me how to properly bleed and adjust the brakes. He thinks I have too much travel on my pedal. Between previous threads and the maint manual I think we can knock it out.
Honestly, I think some of my problem is just me struggling to adjust to the difference in stopping power and speed compared to my regular vehicle. Its taking me some time getting used to 1) driving a stick and 2) drum brakes!
Joined: Aug 31, 2010 Posts: 1741 Location: SO IDAHO
Posted: Thu Dec 05, 2013 3:45 pm Post subject:
Most of us "old farts" grew up on no power steering, no power drums
and stick shifts..i can see how later generation folks might have a
problem adjusting to manual systems. Good Luck and above all
Have Fun and Be Safe.. _________________ keep 'em rollin'
RICKG MC 51986 DOD 01-52, '50 CJ3a
A lot of the trouble today is drum brake maintenance is becoming less common and the smarts that use to be in the shops that repaired old drum brake systems isn't there anymore.
My first 8 cars had drum brakes and only one had power anything. My M38A1 I owned while I was stationed at Ellsworth AFB SD had the stock single res master cylinder and brake system. It had no overdrive and I drove it daily to work from home to Ellsworth (26 miles each way) at 65 MPH with 10-15 mud tires on white spoke wheels. When I hit the brakes at 50 hard she stopped in less than 100 feet. When you drive manual brakes you must learn that you must put some muscle in that leg to operate them. Today's younger folks have lazy legs from being raised on power brakes.
Back to the lack of smarts today when servicing drum brakes. The art of checking brake shoe arc to drum arc, of re-arching shoes, and of shimming shoes is a lost art. Drums have a cut limit on them because if you increase the diameter of the drum too much the shoes won't press hard enough against them anymore and/or the full length of the shoe will not actually make contact with the drum. Usually the only time a stock new shoe will have proper contact with the drum is when the drum is also a stock new drum. Once you turn the drum you must now insure the shoe fits the drum!
Another bite in your crotch comes when you decide to use DOT 5 silicon fluid which has a notoriously soft pedal. Combine that soft pedal with the shoe to drum issues above and you will be one of the many who whine about poor 9" brake performance.
If you feel your brakes are inadequate then get an old timer to drive your jeep and let you know if you really have a problem. Then if they are performing poorly fix them correctly.
As already mentioned above the need for 11" drums or disc conversions arise when you increase the speeds, the weight, HP or the tire size. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
Joined: Jun 09, 2011 Posts: 776 Location: Bellmore, NY
Posted: Thu Dec 05, 2013 5:42 pm Post subject:
I still have the single master cylinder. I replaced my old one with a new one from Jon at Midwest Military, and it has worked like a charm. New 11" drums front and rear, with new wheel cylinders, new brake lines, and a new reservoir help. I talked to Jon, and he says he has used a single master cylinder for years and not had problems. The dual conversion is a bit of a headache, involves drilling the frame, and I want to avoid it if possible. I see no need to check the reservoir every time I go out, which is almost daily, I just give the vehicle a once over every week to make sure everything is fine.
With that 4 cylinder engine, I do 65 max, usually a top of 55, and with the old manual steering, the stock military tires, and the stiff suspension, it better be a decently long straight away to feel comfortable at 60+ miles an hour. _________________ 1952 M38A1
Marine core reinforced rear bumper, military transistorized turn signal upgrade, arctic heater, 11" drum brakes, 200L PTO winch, Huffy overdrive, deep water fording kit, RT 68 vehicle mounted radio, Trac Locs front and rear.
www.danhenk.com
You already have a very well thought out weekly checklist in your Operator's Manual TM 9-8012 pages 62 and 63. Just label the 4th column weekly. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
Joined: Feb 16, 2007 Posts: 206 Location: Gold Coast Australia
Posted: Mon Dec 09, 2013 4:44 pm Post subject:
Some of us old farts were brought up on mechanical & cable braking systems!
Wes is a youngster if he only worked on hydraulic braking systems. & he is on the money with shoes fitting perfectly [& concentrically] to drums.
Also it is a good idea when old or new drums are fitted to hub/s to ensure they are running true by spinning in a brake lathe [very lightly skimming if necessary to bring to round].
If bottom anchored & the above aspect is correct or corrected here are 2 EZ methods of adjusting shoe to drum concentrically, to achieve optimum adjustment.
Jeep MB/GPW etc. [bottom anchored] Foot Brake Major adjustments made simple:
Brake shoes must be concentric with drums. This can’t happen with skimmed drums & standard shoes....
1. Turn all cam adjusters to fully retract all shoes
2. Turn all bottom anchor adjusters so dots [or arrows] face one another
3. Turn anchor in direction of arrow/s until the shoe heel/s drags on drum
4. Turn top cam/s in the arrow direction of the arrow/s to bring the shoe into contact with the drum.
This will cause the shoe/s heel/s to lose contact with the drum
5. Turn the anchors again in the direction of the arrows until the shoe heel/s just drag on the drum/s again
6. Repeat step #4
7. Repeat step #3 & #4 until cam adjustment no longer frees the shoe/s heel, but the shoes are not dragging.
8. Carefully tighten the anchor bolt nut/s & re-check dragging has not been introduced.
9. Repeat procedure for all shoes if you have not already done so
[/u] _________________ John GIBBINS
ASE Master Medium/Heavy Truck & Auto Technician 2002 USA
Licensed Motor Mechanic NSW # MVIC 49593 Current
YOU CAN'T TROUBLESHOOT WHAT YOU DON'T UNDERSTAND
John, I was born in 1947 and to the best of my knowledge just about all the cars and trucks on the road in the city of Camden New Jersey had hydraulic brakes. You gotta go back to the 20/30's for mechanical brakes and that would make you somewhere between 70 and 85 to have been brought up on them.
Of course there were still oldies being restored in the early 50's with mechanical brakes and I worked a few of those back then. Just about every airplane I work on with a birthdate before 1947 has mechanical brakes. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum
Forum FAQ
Search
Usergroups
Profile
Log in to check your private messages
Log in
