Kit should include:
- 1 Aluminum adapter ring
- 1 Master cylinder boot
- 2 Mounting bolts
- 2 Rubber grommets
- 1 Master cylinder reservoir
Parts you will need to get:
Tools needed:
- 11, 13, 14, 24mm wrenches
- 13mm socket
- Large crescent wrench
- Vise grip pliers
Taking off old master cylinder
- Pull off the wires that go to the master cylinder switch(s). Using your large crescent wrench just loosen the switch(s). Now with your 11mm wrench break the metal lines loose that go into the master cylinder.
- With your 13mm wrench and socket loosen the two bolts that hold the master cylinder to the bracket. Take the bolts out.
- Unthread the line by hand and pull the master cylinder down and out. Be careful where you set it; as it still will have a lot of fluid in it.
Installing the master cylinder adapter kit - Buses up to 1966
- Put some brake fluid on the outside of the rubber plugs that came with the kit. Then push the rubber plugs into the master cylinder. Next take the master cylinder reservoir and put some fluid on the inlet ports. Now push the reservoir into the master cylinder.
- Place the boot onto the new master cylinder and then slide the aluminum ring over the boot with the large inside diameter towards the master cylinder. Loosely line up the bolt holes and bolt it up to the bracket.
- Do not tighten; bend the lines around and hand thread into the master cylinder. It is important that the two metal lines that go to the front wheel are threaded in the end of the master cylinder farthest away from the plunger. The rear line and the switch should go into the holes closest to the master cylinder push rod. Note the brake switch will now be coming out of the side of the master instead of the nose of it.
- Once the lines have been hand tightened into the cylinder go ahead and tighten the two bolts that hold the cylinder in place. Now go back with your 11mm wrench and tighten the brake lines. While here use your crescent wrench and tighten the switch
- Put your wires back onto the brake switch.
Installing the master cylinder adapter kit - Bus 1967
- Put some brake fluid on the outside of the rubber plugs that came with the kit. Then push the rubber plugs into the master cylinder. Next take the master cylinder reservoir and put some fluid on the inlet ports. Now push the reservoir into the master cylinder.
- Place the boot onto the new master cylinder and then slide the aluminum ring over the boot with the large inside diameter towards the master cylinder. Loosely line up bolt holes and. Bolt it up to the bracket.
- Do not tighten; bend the lines around and hand thread into the master cylinder. It is important that the metal line that goes to the front wheels are threaded in the end of the master cylinder farthest away from the plunger. The rear line should go the into the hole closest to the master cylinder push rod. Now screw in both switches. Note the brake switch come out of the side of the master pointing down.
- Once the lines have been hand tightened into the cylinder go ahead and tighten the two bolts that hold the cylinder in place. Now go back with your 11mm wrench and tighten the brake lines. While here use your crescent wrench and tighten the switches.
- Put your wires back onto the brake switches.
Adjusting the master cylinder brake rod
Check the rod that goes into the master cylinder from the pedal. It should have an 1/8 inch of play before you can feel the rod make contact with the plunger. Note if there is no play - the plunger will not come back far enough to let the fluid into the cylinder - If it has too much play you will be pushing the pedal down a ways before the master cylinder even does anything. This measurement is really important here so spend some time and get it right.
To adjust the rod use either a 13mm or 14mm wrench and loosen the jam nut on the rod. Now with your vise grips adjust the rod in or out until it feels right. Holding the rod still: tighten the jam nut.
Bleeding your brakes
The idea of bleeding the brakes is to remove the air that has collected in the brake system. Because air is a compressible gas brake fluid is relatively incompressible and you want your fluid as incompressible as possible.
The first thing you have to do is adjust all the brake shoes. Now take your clear bottle and pour a couple of inches of fluid into the bottom of the bottle. Starting with the wheel the farthest away from the master cylinder (the passenger side rear) place your fuel line into the bottle so that the end is in the fluid and place the other end over the bleeder valve. Place your 7mm wrench over the bleeder valve and fuel line have a friend pump the brake pedal slow making sure it returns all the way. Open the bleeder valve while your friend is pumping. Watch the bubbles in the bottle when they stop and you are getting just fluid close the bleeder valve and go to the next wheel (the driver side rear). Always make sure that the reservoir stays full as you are doing this. After you finish the rear go to the passenger side front and then finally the driver side front. Hint: If a bleeder valve has broken off just replace the whole wheel cylinder. The broken bleeder valve is next to impossible to get out and replace and wheel cylinders are cheap. If you step on the pedal and then let off each drum should spin free. If it doesn't replace the flexible brake hose to that wheel cylinder. Also if you have any brake fluid on the shoes; replace them as they make the shoes sticky and this will also cause the bus to pull.
Last steps
Once the brakes are bleed put your wheels back on and hand tighten. Put the bus back on the ground and have someone step on the brakes. With your torque wrench tighten the adapter bolts and the wheel bolt to 80ftlbs. If you are torquing them with your friend stepping on the brakes and the bus moves you did something wrong or you have air still in the lines or a leak in the lines. Find it and fix it now or may you rest in peace.
Drive the bus out a couple of feet and test the brakes if they feel good go a little faster and farther and test again. If everything is working have a friend step on the brakes real hard and you check for any leaks.
If your bus pulls to one side it is more than likely the flex line; or like we said earlier its fluid on the shoes. So if you know the shoes and or pads don't have fluid on them replace the flex line on that wheel; bleed the brakes again and that should do the trick.
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