CarCare

Even though four-wheel disc-brake systems are the preferable way to go—or rather, stop—many vehicles still come equipped with front disc/rear drum systems. And while rear brakes only handle about 25 percent of the braking load, they're still a very important piece of the proverbial braking "pie." If they're not working at peak efficiency, the load they're not carrying, and subsequent wear-related problems, gets foisted on the front brakes. Also, if the vehicle's braking system is a bit under-designed to begin with, the results can be dramatic. Brake rotor "hot-spotting" or even surface cracks, brake pad wear or surface "glazing" can develop—part of a vicious cycle that translates to the driver as a vehicle becomes more and more difficult to stop.

Adjustments
If the two main adjustments that affect rear brake shoe operation are not set correctly, the above scenario can and probably will occur. These adjustments are rear brake shoe adjustment and parking brake adjustment. Rear brake shoe adjustment is for the purpose of putting the brake shoes in the proper relationship to the brake drums, and is accomplished by (usually) some sort of "self-adjusting" mechanism, which will need to be manually set up at the time the shoes are replaced. It's also recommended that its operation is inspected at routine vehicle maintenance intervals and manual adjustment/service be performed at that time, too.


Parking brake adjustment is for the purpose of making the vehicle's parking brake feature operate within the intended range of actuator (foot pedal or hand lever) movement. Its adjustment should be checked at brake shoe replacement and routine vehicle maintenance intervals as well. While we are not going to discuss performing an entire rear brake shoe replacement procedure here, we should highlight some important points for inspection and adjustment of these two parameters, as well as some common mistakes and omissions which can occur during servicing.


We'll assume that you are planning to not only replace the brake shoes, but also the wheel cylinders, and at least the brake spring hardware kit. Before you undertake those tasks, inspections should be made of the following components, and certain questions should be asked concerning them:

Parking Brake
Does the parking brake system work properly—that is, does it hold the car securely on an incline? If not, is the actuator itself working within its intended operating range, and does the ratchet mechanism hold? If the ratchet mechanism doesn't hold the actuator in place, it must be repaired or replaced. If the actuator is working within its operating range, and is being held in place by the ratchet, check to make sure that both wheels are being braked. If that's the case, but braking force is weak, the shoe replacement procedure and the adjustment procedures that we are about to describe should improve that.

Continued on Page 2

Copyright autoMedia.com 2000-2009



 
Photo Guide

Depending on design, the brake shoes, when viewed from the top, should be making firm contact with either the anchor pin or the wheel cylinder contacts.

If the shoes aren't making firm contact, you'll have to loosen the parking brake adjuster until contact is made for both left and right wheels.

The star-type adjuster should always be cleaned and lubricated as part of the brake shoe replacement procedure.

Use the slot in the backing plate or in the drum itself to insert your adjusting tool through, so you can make the adjustment with the drum on.



Related Articles
Bleeding Power Steering
Replacing Brake Pads
Power-Bleeding Brake Systems
Replacement Rotors
ABS Speed Sensor Service


autoMedia Car Blog
Nissan Back on Track with 2010 Lineup
In the late ‘90s, Nissan brought a handful of automotive journalists into its California headquarters. The company was struggling, and it seemed as ... more...

autoMedia CARnival 11-06-09: This week in Auto Blogs
It's the week ending November 6, and we've browsed our favorite automotive blogs all week long to gather the highlights from each.SEMA is not quite ov ... more...

Pricing: 2010 Suzuki Kizashi sedan
Suzuki is coming out swinging with its all-new Kizashi sedan, striking at the vital midsized sedan segment. Each Kizashi features all-wheel drive and ... more...


Forum Highlights
Re: Aluminum wheels and a flat tire
I am sure you have your tire changed by now, but this is a common problem when using aluminum wheels.  Once you realize you have a problem, hitti ... more...

Re: Chevy 3.8L Engine cutout
 I would call it in intermediate job.  You will need some special tools to do it, but if you have some experience doing repairs, and not jus ... more...

Re: The correct Voltage/Amps for Horn??
I'm not sure I have ever seen an actual horn go bad.  When they do stop working, it is usually an electrical issue.  You want to make sure i ... more...


Car Buying Guide

QUICK SEARCH:


Specs, prices, photos & more
SEARCH BY BODY STYLE:
FREE New Car Price Quote
Get the best price - it's easy!
Zip Code

Used Car Buying Guide



2000-2009 autoMedia.com Inc. All Rights Reserved.