Do I need adjustment holes in my brake drums? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

richards72chevy · 10-01-2017, 05:00 PM

I just bought rear brake drums for my 66.They don't have the holes in them to make the adjustment.Do I need them since this system is self.adjustment?

**The Rocknrod** · 10-01-2017, 05:03 PM

Take a look at your backing plates.

richards72chevy · 10-01-2017, 05:55 PM

Quote:

Originally Posted by The Rocknrod

Take a look at your backing plates.

Are you talking about the plate that the wheel cylinder mounts to?

**The Rocknrod** · 10-01-2017, 05:59 PM

Yes. Thats where the hole is. It's oblong, on the bottom.
The drums go round and round on the outside, attached to the axle.
The adjustment is made from the backing plate side, sometimes there will be a rubber plug installed if your lucky. Check this vid out at about the 3:30 mark -
https://www.bing.com/videos/search?q...37&FORM=VRDGAR

richards72chevy · 10-01-2017, 07:41 PM

No holes there either.I thought about drilling a few holes in the new but I don't if the new drums are balanced.

**The Rocknrod** · 10-01-2017, 08:14 PM

Re View the video please. Do Not Drill the Drums!
The adjustments are made as the video shows, Not through the drums.
Your on the internet - Post some pictures for us please.

geezer#99 · 10-01-2017, 10:40 PM

Quote:

Originally Posted by richards72chevy

I just bought rear brake drums for my 66.They don't have the holes in them to make the adjustment.Do I need them since this system is self.adjustment?

Don't drill the drums, drill and make a slot for the plug in the backing plate. Plugs can be found in the help section of your local parts store.
You need to adjust the shoes when first installed and then let the self adjusters fine tune them. You also need the plug/hole to maybe back off the brake pads if you need to remove the drums sometime in the future.

Brad54 · 10-01-2017, 11:58 PM

Quote:

Originally Posted by richards72chevy

I just bought rear brake drums for my 66.They don't have the holes in them to make the adjustment.Do I need them since this system is self.adjustment?

luvbowties · 10-02-2017, 01:01 AM

Quote:

Originally Posted by richards72chevy

I just bought rear brake drums for my 66.They don't have the holes in them to make the adjustment.Do I need them since this system is self.adjustment?

See #19: http://67-72chevytrucks.com/vboard/s...d.php?t=628322 Hole in Drum.

See Hole in Backing Plate: https://www.google.com/search?q=rear...=1506920130931

racecougar · 10-03-2017, 08:34 PM

As shown in the link luvbowties posted above, the replacement JB5 Raybestos drums I purchased featured knockouts. The JB5 backing plates sourced from a later 12-bolt did not. Adjusting through the drums works just fine.

richards72chevy · 10-08-2017, 03:59 PM

Thanks for all of the response.Looks like I will be putting a hole on that plate
Instead of the drums.Thanks you guys

10-01-2017, 05:03 PM	#2
The Rocknrod Moderator Join Date: Aug 2011 Location: China Spring, TX Posts: 7,280	Re: Do I need adjustment holes in my brake drums? Take a look at your backing plates. __________________ Master Chief, US Navy, Retired 1964 C10 Step-side Short Bed - In Progress 2009 2500HD Duramax LTZ 1948 GMC Panel 1956 Big Window Stepside 1953 5 Window Chevy Stepside 1932 Coupe New Seat Foam for Bench Seats?

10-01-2017, 05:59 PM	#4
The Rocknrod Moderator Join Date: Aug 2011 Location: China Spring, TX Posts: 7,280	Re: Do I need adjustment holes in my brake drums? Yes. Thats where the hole is. It's oblong, on the bottom. The drums go round and round on the outside, attached to the axle. The adjustment is made from the backing plate side, sometimes there will be a rubber plug installed if your lucky. Check this vid out at about the 3:30 mark - https://www.bing.com/videos/search?q...37&FORM=VRDGAR __________________ Master Chief, US Navy, Retired 1964 C10 Step-side Short Bed - In Progress 2009 2500HD Duramax LTZ 1948 GMC Panel 1956 Big Window Stepside 1953 5 Window Chevy Stepside 1932 Coupe New Seat Foam for Bench Seats?

10-01-2017, 07:41 PM	#5
richards72chevy Registered User Join Date: Dec 2010 Location: konawa ok/oakdale Ca. Posts: 1,652	Re: Do I need adjustment holes in my brake drums? No holes there either.I thought about drilling a few holes in the new but I don't if the new drums are balanced.

10-01-2017, 08:14 PM	#6
The Rocknrod Moderator Join Date: Aug 2011 Location: China Spring, TX Posts: 7,280	Re: Do I need adjustment holes in my brake drums? Re View the video please. Do Not Drill the Drums! The adjustments are made as the video shows, Not through the drums. Your on the internet - Post some pictures for us please. __________________ Master Chief, US Navy, Retired 1964 C10 Step-side Short Bed - In Progress 2009 2500HD Duramax LTZ 1948 GMC Panel 1956 Big Window Stepside 1953 5 Window Chevy Stepside 1932 Coupe New Seat Foam for Bench Seats?

10-03-2017, 08:34 PM	#10
racecougar Registered User Join Date: Jan 2013 Location: Imperial, MO Posts: 1,003	Re: Do I need adjustment holes in my brake drums? As shown in the link luvbowties posted above, the replacement JB5 Raybestos drums I purchased featured knockouts. The JB5 backing plates sourced from a later 12-bolt did not. Adjusting through the drums works just fine. __________________ Rod @ AzzKicker Cars 1965 C10 SWB - Build Thread

10-01-2017, 05:00 PM	#1
richards72chevy Registered User Join Date: Dec 2010 Location: konawa ok/oakdale Ca. Posts: 1,652	Do I need adjustment holes in my brake drums? I just bought rear brake drums for my 66.They don't have the holes in them to make the adjustment.Do I need them since this system is self.adjustment?

10-08-2017, 03:59 PM	#11
richards72chevy Registered User Join Date: Dec 2010 Location: konawa ok/oakdale Ca. Posts: 1,652	Re: Do I need adjustment holes in my brake drums? Thanks for all of the response.Looks like I will be putting a hole on that plate Instead of the drums.Thanks you guys



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.