Joined: Dec 03, 2013 Posts: 197 Location: Saint Augustine , Florida
Posted: Fri Oct 17, 2014 12:31 pm Post subject: brake shoes/drums m38
working on a 38 the shoes are not contacting the bottom of the drum on adjustment on the old drums or new drums, new shoes long on front, all new hardware, wheel cylinders buzz
Are the new drums actually new or just a set of turned drums? If turned drums then the shoes must be re-arched for a small cut and shimmed for a large cut. I don't recall any source for brand new M38 drums. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
Joined: Dec 03, 2013 Posts: 197 Location: Saint Augustine , Florida
Posted: Sat Oct 18, 2014 8:56 am Post subject:
I be-leave they are crown automotive drums This is the first time this has happened in all the jeeps I have restored always have used old drums turned buzzz
Do you have two eccentric adjusters at the bottom for the shoes or two center and two lower eccentrics or a lower adjusting tooth wheel only? _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
I'll hope you meant to say two on the center of the shoes and two at the bottom. Never saw any up top. If this is as you say then I see only six possibilities.
1-Drum inside ID too large.
2-Shoes two small (wrong shoes)
3-Linings too thin. (wrong linings)
4-Eccentrics worn out or incorrect for your installation.
5-Eccentric's contact point on the shoes worn excessively.
6-There is nothing wrong as the proper adjustment at the bottom of the shoe is set with a feeler gage thru the drum slot to 0.005". Not suppose to touch the drum until you apply the brake hydraulicly. Correct clearance on top is 0.008". TM 9-8012 page 281. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
There you have your answer. These are not adjust till you get drag brakes. The drums are not M38 drums (no slots). The solution is put slots in the new CJ drums or get M38 drums with slots or suffer unequal (top to bottom) shoe wear and poor braking. Any attempt at adjusting to drag by applying slight hydraulic pressure will result in unequal wear and unequal braking unless you can maintain an exact and constant amount of pressure to all four brakes equally then start the adjustment with all 4 eccentrics on each brake fully retracted and then advance them equally until you are sure you have equal (top to Bottom) shoe engagement with the drum one shoe at a time. You could set pedal pressure say 1/4" beyond the end of pedal free play and clamp things at that setting. Since you already have pressure applied you want only a very light drag at each shoe and with hydraulic pressure released you want no drum contact with the shoe. If you allow contact with brake released I can assure you it will be top shoe contact and unequal wear will occur loosing the top meat quickly. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
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