DIY Network

Inspect Rear Hydraulic Brakes, Bleed Brake System From "Classic Rides" episode DCLR-104

Figure A

In the last segment host Kevin Tetz and Harley-Davidson expert Bill "Dunk" Dunkelberger inspected the primary chain and clutch and installed a new clutch cable. IN this third segment the rear hydraulic brakes are inspected and Kevin bleeds the brake system.

The rear brakes of the project '65 Electra Glide are hydraulic (figure A) and the front brakes are mechanical, operated by a lever. They're both drum brakes. During the test drive Kevin said the brakes felt good, but since the system is broken down now it's a good idea to go ahead and pull the drum out and give it a good inspection.

Note: Keep in mind that brake fluid tends to deteriorate over time, so if you're pulling your bike out of storage it's a good idea to check the reservoir and bleed the system out.

advertisement

Inspecting the Rear Hydraulic Brakes

• What you should look for first are signs for moisture and leakage around the cylinder. (On the project bike everything looks good.)

• Next check the pad and shoe depth. You can do this by putting a new set beside the old ones (figure B). Make sure the rivets are deep set.

• Check the drum (figure C) for wear and if there are any grooves. (Everything is fine on the project bike.)

• If everything looks fine on your bike, put the pad and drum back in place.

Figure B

Figure C

	Figure D
	Figure E
	Figure F

Bleeding the Brake System

• The first step is to check the fluid level and color (figure D).

  Note: You'll probably have to add brake fluid to your system while bleeding the brakes because you don't want to let the fluid level go down to the bottom. This will introduce air into the system, and you'll have to start all over again. And while you're adding fluid make sure to use a compatible brake fluid for your bike. (The DIY project bike uses a Dot 3 or Dot 4 glycol-based brake fluid.)

  Warning: Don't mix a Dot 3 or Dot 4 with silicone based Dot's brake fluid. Also, the Dot 3 and Dot 4 fluids have a shelf life, so be aware of this as soon as you break the seal. And if you upgrade to a Dot 5 system, you'll need to bleed out the old brake fluid completely.

• There are a few different systems you can use when bleeding brakes:
  1. The two-man system is where one person operates the foot pedal and one person operates the bleeder screw, and you can go back and forth to purge the system.

  2. Or you can use a vacuum power single-man vacuum pump (figure E). This system hooks up to the bleeder screw where you can monitor the system and just vacuum the fluid out. This is a one-person system.

  3. Kevin chose to use a air-assisted model (figure F) on the project model.

• Hook the air-assisted model to the airline and let it go and it automatically vacuums and purges the system by itself. All you'll need to do is keep an eye on the master cylinder to make sure it has fluid in there.

• Crack open the bleeder valve about a half turn, and then attach the suction tube of the tool to the bleeder valve. Attach the compressed airline to the unit.

  Note: Don't turn the unit on until you are by the cylinder in order to monitor the fluid level.

• Turn on the unit and add brake fluid as needed. And be sure to replace the cap on the brake-fluid reservoir.

• Once the bleeding is done thread the cap back on the cylinder -- but not too tight.

In the final segment the front brakes will be serviced by installing a new cable and brake shoes.

RESOURCES :

Dremel Tools
Website: www.dremel.com

The Eastwood Company

The Eastwood Company is a supplier of automotive-restoration parts, tools and supplies.

The Easthill Group, Inc.
The Eastwood Company
Website: www.eastwoodco.com

Eazyrizer Big Blue Motorcycle Lift (Driven Gear)
Driven Gear Inc.
Website: www.drivengear.com

RaceDeck Modular Flooring (SnapLock Industries)
SnapLock Industries
Website: www.racedeck.com

Restoration Parts (Custom Chrome)
Custom Chrome
Website: www.customchrome.com

CycleDry Compact Motorcycle Dryer (Georgia Cycle Works)
Georgia Cycle Works
Website: www.cycledry.com

GUESTS :

William "Dunk" Dunkelberger
Restoration Coordinator / Mechanic
Harrly Hoggs & Piggletts
1409 Piney Rd.
Maryville, TN 37803
Phone: 865-681-7699
E-mail: hoggsandpiggletts@yahoo.com