brake shoes/drums m38

buzzk · Post by **buzzk** » Fri Oct 17, 2014 12:31 pm

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

Post by **wesk** » Sat Oct 18, 2014 7:57 am

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.

buzzk · Post by **buzzk** » Sat Oct 18, 2014 8:53 am

they are brand new got them from midwest buzz

buzzk · Post by **buzzk** » Sat Oct 18, 2014 8:56 am

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

Post by **wesk** » Sat Oct 18, 2014 10:40 am

They civvy 9" drums or civvy 10" drums? Are your linings the correct thickness.

buzzk · Post by **buzzk** » Sat Oct 18, 2014 12:25 pm

they are standard drums for the 38, 9" brand new shoes, long on the front buzz

Post by **wesk** » Sat Oct 18, 2014 4:05 pm

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?

buzzk · Post by **buzzk** » Sat Oct 18, 2014 9:53 pm

standard M-38, 2 eccentrics on bottom and two on top buz

Post by **wesk** » Sat Oct 18, 2014 10:35 pm

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.

buzzk · Post by **buzzk** » Sun Oct 19, 2014 8:29 am

every thing is brand new, shoes from AJP all new hardware from DeBella, drums from Midwest The new drums do not have the slots for feeler gauge

Post by **wesk** » Sun Oct 19, 2014 9:05 am

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.