Date:         Fri, 2 Sep 2022 14:06:10 +0000
Reply-To:     Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject:      Happy Friday, Rear brake adjustment.
Content-Type: text/plain; charset="us-ascii"

Here is a link for some pictures that maybe helpful.
https://1drv.ms/u/s!AqaEiIhKCAKbiJIYx-ZxNT_kclWRdg?e=A35dub

When it comes to brakes the Vanagon gets some poor press for the brake design, and the choice that they still used drum brakes in the rear. Yes some of that decision was likely based on cost, except for the self-adjusters these brakes are carryovers from the bay windows. Still while most modern cars have disk brakes, drum brakes are still the usual choice for trucks and busses. Drum brakes simply offer more surface area for friction and heat dissipation. Disc rely more on physics and clamping forces. Discs are also more consistent, weather resistant, and give better pedal feel of mechanical-hydraulic systems.

That said a downside of drum brake systems is that they are somewhat maintenance intensive and set-up adjustment, and fitting of parts is critical. The Vanagon adds a bit with the design of the handbrake system, the finicky ness of the adjustment system, the closed drum-backing plate, and the lack of proper parts, especially the shoes for service.

Getting to the maintenance side of this, many like to think that we can do a brake job and it should last for some long period of time. With the drum brake set up there are number of maintenance items that often will not last the life of the shoes. Thanks to the composite drum design, (drum separates from flange), service and inspection is actually quite easy. Unless the shoes are deeply worn into the drum or this is a major rust ridge on the drums behind the shoes, or on the drive flange, the drums are easily removed anytime the wheel is removed. No need to remove the axle nut. Once the 2 assembly screws are removed, the drum can usually be popped off hitting the edge with a dead blow hammer. If needed the adjusters can be backed off to allow the shoes to clear the ridge. If really difficult to remove service has been neglected way to long.

With the drum off you want to do an inspection. . With the closed design the drum will usually be filled with brake dust. You want clean this out as that dust churning in there is not good. Check the condition-straightness of the backing plate. Look for signs of wheel bearing grease and brake cylinder leakage, check the wear pattern on the shoes, look for signs of heat checking, glazing, cracking, and separation of the lining from the shoe. This is more common with vans that sit outside as the shoe starts to rust, the rust will jack the lining off the shoe causing the bond to fail. BTW this also happens with disc pads. Back to the cylinders, check again that you have the correct ones with the internal spring to prevent the pistons from sucking back.

Then you want to check the hand brake and adjuster parts. Check that the lever moves freely, along with the cables. It is common for the cable sheaths to fail internally causing the cable to bind, not allowing the levers on the shoes to fully return. Check that the levers move freely, not rusted in place, and the adjuster screw can turn freely. Lubricate with liquid graphite or other favorite light lubricant. Avoid grease or never seize.

Now for the handbrake adjustment. The only way to properly adjust the handbrake is for the drums to be removed so you can see the lever position against the push-adjuster rod assembly. To make this a little easier remove the spring that lifts the adjuster lever. This takes that push off the adjuster rod. For a new shoe install, adjust the rod to take up all the slack between the shoes. Then you want to adjust the brake cables to just touch the adjuster rod. Check that both sides are the same. Again this is the only way to adjust the handbrake. Same if a follow up adjustment is needed for cable sheath or sheath collapse. Then place the spring back on the adjuster lever. With care the adjuster can be tested by carefully using the brake pedal to push out the shoes. As the shoes move out the adjuster lever will turn the adjuster nut, when release the lever will drop and then be able to grab the next tooth on the adjuster nut. For this to work, again the handbrake lever cannot be putting any pressure on the adjuster-push rod.

With the drums back on pump the brakes a few times to center the shoes. For a new install you can usually hear the adjusters click as you operate the brakes with the pedal. For new shoes I will manually adjust the brake adjuster to give a very light rub. This gets the shoes seated. For used you want some clearance and should able able to turn the rums with no drag at all.

For inspection frequency, the rear should be checked after any known abusive brake event, when tires are removed for rotation 5-7K miles) and at least once/year for little used vehicles.

Hope this helps!
Dennis