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Removing Troublesome Brake Drums

©2004 Eric Neyerlin - ZPARTS.COM

Quite often drums can become rust & corrosion bonded between the inner backside of the drum and the cast iron hub surface leading to major difficulties when removing the drum for service. If gentle tapping and rocking of the drum back and forth does not lead to removal, try some of the approaches listed below.

Approach One: First, jack up your car and place it on very solid jack stands, remove the wheel and screw the lug nuts back onto the studs enough to protect the threads while working. Keeping in mind that Nissan drums are made of aluminum and hence, prone to permanent warpage and chipped fins, try these 2 steps in this order.


Step 1 . Gently use a heavy hammer to tap around the outer surface of the drum's circumference. Next, using a short (6"-8") block of wood, position it at the rear edges the finned drum area and use a heavy hammer to strike several hardy blows to the other end of the wood block. (Fig 3) With luck, you will see the drum visibly cock outward on that side. If it does, rotate the drum 180 degrees and do the same thing again or continue the rotation process until you get results. This is the safest and usually quickest way. Working at the rearward edge of the drum will afford you with the most area to freely swing the hammer. The wood block is meant to protect the delicate aluminum fins from chipping off, plus the wood grain end will usually dig in and grip the fins while protecting the metal

Caution: Do not continue to beat on just one point on back side of finned drum without moving to the opposite side (180 degrees) or at least several inches further along circumference in order to avoid the risk of permanently warping metal drum from excessive blows concentrated at one point.


Step 2. If you do not break the drum loose quickly with step 1, try using a heavy rubber mallet (fig. 5) or medium weight steel mall (read cautions FIRST) to strike modest, tapping blows to the outer surface of the drum in a circular pattern that works around the perimeter of the drum just inside the lug nut area (blue circle shown in Fig. 4a). Next move to the outer perimeter just inside the finned circle (red circle shown in Fig. 4a ) and repeat your modest tapping blows in a circular pattern around the drum (Fig. 4b).


The aim is to cause the drum to slightly "cock" itself inward at the point of the blow. By tapping all around the circular perimeter of the drum, you will be trying to cause the drum to slightly "cock" inward in all directions, hopefully breaking the bond formed behind the drum. After 5-10 blows, use your 2 hands to try to rock the drum loose further and pull it off or return to step 1. If nothing happens, repeat with more blows and so on.


You can also attempt to work from behind the drum to tap the backside of the aluminum fins with a small metal hammer, but it is very easy to do more damage than good and working like this on the car is very cramped. If you have the entire suspension removed from the car, you can place a block of hardwood up against the back side of the fins and hammer backwards on it and reduce the risk of damage quite a bit. Caution. Whack'in too hard, for too long, at one point, can result in a permanently warped drum.


Big Caution: Getting carried away with the force of your blows to the outside of the aluminum surface can result in a permanently warped drum. Go slow and gentle in the beginning. Heavy metal steel hammers are more likely to do permanent damage compared to heavy rubber or plastic mallets so choose your tools carefully for this job. Using a wood block between the metal hammer and drum is also a good idea.


The Heat Option. There is a more drastic approach that can be taken, but not one recommended for the beginner. Some shops will sometimes apply heat from a propane or welding torch to the outer aluminum drum surface in an attempt to cause the corrosion and rust bond to be weakened by the expansion and contraction of the 2 different metal surfaces. Very easy to permanently damage the drum using this method so use it only as a last resort.


Approach Two: A second problem to drum removal results from either brake shoes becoming frozen in position due to an emergency parking brake being left tightened for long periods or because brake components and cables have become gunked up to the point that components will not release with counter spring pressure . Also, if brake shoes are left in a tightened position during rainy months, a rust bond will sometimes develop between the shoe and the drum's steel friction surface (Fig 1b) that can establish a rather strong grip on the shoe.


With the rear of the car jacked up, front wheels braced,transmission out of gear and the parking brake released, if your brake drum will not rotate freely or if it drags noticeably, then you may have one of the conditions mentioned.


Step 1. First, make sure that your parking brake linkage near the backside of the hub is releasing totally (Fig. 2A). If the brake cable fastener seems taunt after you release the handle you may need to tap the connecting lever (Fig. 2B) with a hammer in the direction of release to remove the tension.


Step 2. Once you are satisfied that the lever has been backed off as far as is mechanically possible, the next step is to ascertain whether the brake shoes are backing off far enough to clear any brake drum wear grooves that they may have sunk into. Sometimes brake shoes wear a groove so deep into the drum lining that when they disengage from the friction surface, they still will not retract far enough to allow a drum to be pulled off without the non-worn, outer edge of the drum from catching the brake shoe.


If this situation is suspected, there is a manual brake shoe adjustment access hole (Fig. 4) (usually filled with a removable rubber plug) on each drum that can be rotated to a point (slightly off position from dead bottom-see illustration photo in my web site article) where a small tool, such as a long, thin shank, flat tipped screw driver, can be used to back off a cogged adjustment wheel inside the drum that will mechanically retract the brake shoes far enough that they will then clear the drum friction edge. Hopefully, the drum will then come off without further problems. Consult a Nissan manual to clarify the fine points of this adjustment process.

Lastly, attending to a little preventive maintenance before reinstalling the brake drum can be wise. Using a wire brush on the end of an electric drill some 80 grit sandpaper, grind down the rust and corrosion areas that caused the problem in the first place. See Fig. 1A -1B and Fig. 6A and inset photo that show areas of greatest concern to attend to before reassembly.

Note of Caution, I have heard some suggest that an anti seize compound or thick grease applied to these problem areas before reassembly will protect against problems in the future, but IMO these products, if applied a wee to aggressively, can lead to them being spread by centrifugal force out to the brake shoe area. If these lubricants should get onto friction surfaces, a car's braking capability could be compromised down the road so use caution with this approach. Personally, I do not recommend their use in the brake hub areas.

Eric Neyerlin - owner of Z PARTS


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Last Updated April 5, 2004
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