How to Replace a 2005 Dodge Grand Caravan's Master Cylinder

Smaller vans came before it and more minivans came after it, but when someone mentions the word minivan, the first thought of most car people is the Caravan. The Caravan broke the ground for every other major car manufacturer to produce a minivan of its own. The 2005 Grand Caravan came standard with four-wheel disc brakes, as well as four-wheel antilock brakes. Powering this brake system is a hydraulic component: the master cylinder. As you press the brake pedal, the master cylinder delivers pressurized hydraulic fluid to the brake calipers. After replacing the master cylinder, you must bleed the brake system.

Instructions

Replacing the Master Cylinder

1

Press and release the brake pedal five times to relieve all vacuum from the brake booster.

2

Loosen the negative battery cable with a combination wrench and pull the cable from the negative battery terminal. Loosen the positive battery cable with a combination wrench and pull the positive battery cable from the battery.

3

Pull the plastic battery shield upward and off the battery. Remove the nut securing the battery hold-down clamp with a ratchet and socket, and remove the battery hold-down. Pull the battery from the Grand Caravan.

4

Press and hold the unlocking button on the fluid level sensors wiring harness, and pull the wiring harness from the master cylinder.

5

Hold a small drain pan under the master cylinder. Loosen the two brake line fittings with a line wrench. Pull the brake lines from the master cylinder and allow all of the fluid to drain from the brake lines and the ports on the master cylinder.

6

Remove the master cylinder-to-brake booster nuts with a ratchet and socket, and pull the master cylinder off the brake booster.

7

Set the new caliper in a bench vise with rubber jaw protectors and tighten the vise to secure the master cylinder. Do not over-tighten the vise, as it can crack the master cylinder. Unscrew the master cylinder reservoir cap and fill the reservoir to the Max line with new DOT 3 brake fluid. Remove the plastic sealing caps from the brake line ports.

8

Hand-thread bleeder hoses from the master cylinder bleeding kit into the brake line ports on the new master cylinder. Route the bleeder hoses into a clean, clear container. Fill the clean, clear container with fresh DOT 3 brake fluid until the fluid submerges the end of the hose.

9

Press and release the plunger on the rear of the master cylinder with a wooden dowel rod and watch the submerged ends of the two hoses. Continue pressing and releasing the plunger until no more bubbles come from the bleeder hoses.

10

Unscrew the bleeder lines from the master cylinder with a line wrench and quickly install the plastic sealing caps back into the brake line ports.

11

Check that the vacuum seal -- the O-ring-like seal -- on the rear of the master cylinder seats squarely in its groove. Press it into the groove, as needed.

12

Remove the master cylinder from the bench vise and set it on the mounting studs on the brake booster. Hand-thread the master cylinder-retaining nuts onto the mounting studs, then torque these nuts to 19 foot-pounds with a torque wrench and socket.

13

Remove the sealing caps from the brake line ports, and quickly hand-thread the brake lines into their respective ports on the master cylinder. Torque the brake line fittings to 12 foot-pounds with a torque wrench and a crows foot attachment.

14

Plug the brake fluid level sensor wiring harness into the receptacle on the master cylinder.

15

Set the battery back on its tray. Place the battery clamp in place and hand-thread its retaining nut. Tighten the battery clamp nut with a ratchet and socket. Slide the battery shield back over the battery. Install the negative battery cable and tighten its nut to 11 foot-pounds with a torque wrench and socket. Install the negative battery cable and tighten its nut to 11 foot-pounds.

16

Add DOT 3 brake fluid to the master cylinder until the level reaches the Max line on the reservoir. Tighten the cap onto the master cylinder reservoir.

Brake Bleeding

17

Raise the rear of the van with a floor jack and slide jack stands under Grand Caravans rear suspension. Lower the van to the ground. Raise the front of the van with a floor jack and slide jack stands under the subframe. Lower the van onto the jack stands.

18

Crawl under the rear of the van, so that you are directly behind the left rear wheel. Look on the top of the brake caliper to find the bleeder valve -- the -inch metal valve -- and press the end of a -inch-diameter rubber hose onto the bleeder valve.

19

Set the free end of the rubber hose into a clean, clear container. Fill the container with DOT 3 brake fluid until fluid submerges the rubber hose.

20

Instruct an assistant to press and release the brake pedal three to four times, until it feels firm. Tell your assistant to press the brake pedal as far to the floor as he can and hold it. Turn the bleeder valve one turn counterclockwise with a combination wrench to open it. Look at the submerged end of the hose and watch for air bubbles to appear in the brake fluid. Tighten the bleeder valve and instruct your assistant to release the brake pedal. Repeat this step until no air bubbles come from the hose submerged in the brake fluid.

21

Remove the rubber hose from the bleeder valve. Refill the master cylinder to the Max line with new DOT 3 brake fluid.

22

Repeat Steps 2 through 5 on the remaining three wheels, in the following order: right front, right rear, then left front.

23

Raise the front of the van off the jack stands with a floor jack and remove the jack stands. Lower the front of the van to the ground. Raise the rear of the van off the jack stands and remove the jack stands. Lower the rear of the van to the ground.