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How To Replace Rear Drum Brake Wheel Cylinder 84-91 GMC Jimmy

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  1. step : Removing the Wheel (1:03)
    • Raise and Secure the Vehicle
    • Remove the Lug Nuts
    • Remove the Rear Wheel
  2. step : Accessing the Wheel Cylinder (1:17)
    • Pull off the brake drum
    • Remove the springs with vise grips. The longer one is the front spring.
  3. step : Removing the Wheel Cylinder (1:43)
    • Disconnect the brake line using a wrench or vise grips
    • Be careful not to twist the brake line
    • Remove the wheel cylinder bolts
    • Pull out the wheel cylinder
    • Put the wheel cylinder plungers aside to reuse
  4. step : Replacing the Wheel Cylinder (3:23)
    • Put the wheel cylinder in place
    • Start reconnecting the brake line nut by hand
    • Start the wheel cylinder bolts by hand
    • Tighten the bolts to 20 foot-pounds with a socket
  5. step : Replacing the Brakes (4:22)
    • Attach the plungers
    • Reattach the front spring with the vise grip
    • Reattach the rear spring with the vise grip
    • Replace the Brake Drum
  6. step : Bleeding the Brakes (6:08])
    • Run a hose into a plastic bottle or drain pan
    • Attach the hose to the bleeder valve
    • Enlist the help of an assistant
    • Instruct the assistant to press the brake pedal
    • Release the bleeder with a wrench
    • Tighten the bleeder
    • Instruct the assistant to release the brake pedal
    • Repeat until no more air flows
    • Repeat this process for each wheel
  7. step : Replacing the Wheel (7:37)
    • Replace the wheel
    • Tighten the lug nuts
    • Let the vehicle down to the ground
  8. step : Road Test the Vehicle (7:41)
    • Press the brake pedal
    • Put the vehicle into gear
    • Check that the brakes hold with the vehicle in gear
    • Test the brakes at low speeds before testing on the road
    • Test the brakes on the road

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Hi, I'm Mike Green. I'm one of the owners of 1A Auto. I want to help you save time and money repairing or maintaining your vehicle. I'm going to use my 20-plus years experience restoring and repairing cars and trucks like this to show you the correct way to install parts from The right parts installed correctly: that's going to save you time and money. Thank you and enjoy the video.

In this video, we're going to show you how to replace the rear wheel cylinders on this GMC Jimmy, same as pretty much any drum brake vehicle. Tools you'll need are various wrenches and pliers. You'll need obviously to jack up and secure the car. Then you'll need the tools to remove your wheels, and then from there on, you need various pliers and then smaller wrenches to remove the wheel cylinders.

Rear emergency brake cable replacement on the truck here with drum brakes. Obviously, first thing you need to do is remove the rear wheel. After you get your rear wheel off, then pull the drum off. Here's your brakes. You're going to want to remove these two springs. You can see the longer one is the front one.

Once you have the brakes apart, you can see right back here, this is our rear wheel cylinder. First, you're going to remove the brake line and this is probably a 3/8 or 7/16 inch nut, but I generally just latch right on here with vise grips, because usually these are pretty rusty. They just break away easier using a set of vise grips. You want to be careful that you're not twisting your brake line, that this is coming apart cleanly because once you twist the brake line, then you've got to replace it.

These two little bolts on this truck are 3/8 inch. Then after you get those out, you can pull the wheel cylinder up and out. There's your wheel cylinder. In general, you want to keep these plungers because the wheel cylinders usually don't come with those.

I'm going to pop the wheel cylinder through that. I'm going to get the nut started first. Once that's started, then I'll push the wheel cylinder in the rest of the way here. I'll use my bolts. Tighten those up, and these are usually about 20 foot-pounds which is just tight with one of these smaller wrenches.

Put our plungers in place here. First we grab this. Then our long spring goes in here. Get this all lined up over here. Then our smaller spring. Everything's back together.

After you do brake work, you should always bleed the brakes, so what I've got here is a bottle of brake fluid in it and a wrench to put on my bleeder here, and then a hose. Then I have an assistant in the car, and when I say "Brakes," he's going to press the brakes and I'm going to release the bleeder.

"Brakes." That's going to allow fluid to go into the wheel cylinder and air to get out. "Let off." "Brakes." "Let off."

If you listen very well, you will hear if there's air coming out of the bleed or not.
"Let off." "Brakes." I heard it that time. "Let off." "Brakes." "Let off." "Brakes." "Let off." "Brakes." "Let off." How's the pedal feel?

All right, I guess."?

"Brakes." "Let off."

Then whenever I bleed the brakes, I always check all four wheels. Now we're going to put our tires back on and take it for a road test. Any time you road test the car after doing brake work, what you want to do first is put your foot on the brake and put the car in gear and make sure that the brakes hold the car just in gear, and then you start out slow, make sure the brakes will stop the car before you get it on the road and then have to depend on the brakes. Try a couple a stops where there's nothing in front of you and then go from there.

We hope this helps you out. Brought to you by, your source for quality replacement parts and the best service on the Internet. Please feel free to call us toll-free, 888-844-3393. We're the company that's here for you on the Internet and in person.

Tools needed for replacement:

    General Tools

  • Jack Stands
  • Drain Pan
  • Assistant
  • Floor Jack

  • Materials, Fluids, and Supplies

  • Rubber Vacuum Hose

  • Pliers, Cutters & misc Wrenches

  • Vise Grip Pliers

  • Sockets - SAE

  • 3/8 Inch Socket

  • Wrenches - SAE

  • 3/8 Inch Wrench

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