Page 1 - Rear Drum Rebuild

Beat of the Drum – InlineTube Drum Kits - Text by John Kryta – Photography John Kryta

There is nothing exciting about drum brakes, although most cars have them even today. I thought there was a time
were all newer cars and trucks would have 4-wheel disc brakes making the drums obsolete but to my surprise my
2010 GMC truck still has rear drum brakes. When I questioned why the Disc’s I found out that all the GM trucks went
back to drum brakes in the rear. There were many problems with the disc’s and the good old industry trusted drums
remain - said the sales man.

I am not here to debate whether disc or drum is better. I just know millions of GM cars were outfitted with them. The
car we are working on is a 69 GTO with 9 ½” drum brakes. It turns out that this is the same unit that is used on all GM
mid size cars in the 60’s and 70’s. GM used this unit on all 64-72 A-bodies which includes the GTO, Tempest, Lemans
and the other makes like Chevelle, 442 and Skylark. It was also used on the F/X body cars that includes 67-81
Firebird, Trans Am and 71-74 Nova Style Ventura / GTO. So pretty much the entire, small to mid size line up had 9 ½”
rear drum brakes. The big Catalina and Bonneville got the slightly larger 11” brakes. There are a few minor changes
from car to car which include a 1/16” bigger or smaller wheel cylinder and the length of the parking brake cable but the
internals are all the same.

Now that your brakes are 30 - 40 years old it is time to take a look and see what is left. If the shoes are worn out
maybe it is time to replace all the hardware since it all has to come apart to get the shoes out. Another thing to
remember is there is a difference between the right and left side so do one side at a time and do not mix the parts
together. Inline tube offers a complete line of drum parts so if you just need a spring kit or a wheel cylinder it is no
problem. If your system is in need of a complete overhaul Inline Tube also offers the complete set assembled and
ready to bolt on. The complete set comes as a unit with all the correct color coated springs, plated hardware, parking
brake arm and other hardware that is not available anywhere. When you consider the cost of rebuilding all the pieces
including turning the drums and re-painting or plating the parts the complete unit really takes the work out and saves
money. By following the steps below you can rebuild you components just like an experienced mechanic or buy a unit
that is ready to bolt onto your classic.

Picture 1 - This GM drum set up was used on over a few million cars here is a list of the common applications.
1964-77 GM A-body Chevelle, GTO, 442, Gran Sport, Monte Carlo, Grand Prix, Elcamino
1967-81 GM F-body Camaro, Firebird, Trans Am
1968-74 GM X-body Nova, Ventura, 64-67 Chevy II / Nova, 75-79 Nova, Skylark, Omega, Ventura
1965-69 Corvair, 1976-77 Vega/Astre 1976-80 Monza, Skyhawk, Starfire, Sunbird,
1977-85 GM B-body Impala / 1977-96 Caprice.