Bleeding Procedures - All Vacuum Units

It is recommended that all brake bleeding be performed with a pressure bleeder.
If one is not available, use the following procedure.

Frame Mounted: 2 Line Units
DO NOT RUN ENGINE WHILE PERFORMING BLEEDING OPERATIONS.

1.	Fill the reservoir of the new, rebuilt or flushed out master cylinder with new, clean, heavy-duty brake fluid.
2.	During bleeding check frequently to make certain that fluid in master cylinder reservoir maintains at least 1/2 inch of fluid. Failure to do so may require starting all over.
3.	Loosen tube nut to pre-bleed master cylinder and slowly pump master cylinder until fluid runs clear. Re tighten nut.
4.	Bleed power unit as required. Pump pedal slowly to avoid creating air bubbles in fluid. Bleeder screws should be opened on the pressure stroke of the master cylinder and closed on the return stroke.
5.	Continue around vehicle wheels until all bleeder screws run clear.
6.	Refill master cylinder reservoir and slowly pump pedal with no bleeder's open. This allows master cylinder to evacuate any air bubbles that may remain in cylinder bore. Air will escape through compensating port in the reservoir bottom.
7.	Start engine, pump pedal two or three times. Then allow time for fluid to return to the reservoir. If pedal is firm but has excessive stroke, adjust brakes at all wheels. If pedal is spongy, it still has air in the hydraulic system. See step 8.
8.	Some vehicles may require "serge" bleeding. To accomplish this, have engine running at idle and make a firm pedal application. Open and close wheel cylinder bleeder screws very quickly. Do not let the pedal go clear to the floor. Repeat this step at each wheel. Remember to check brake fluid level in reservoir.
9.	Proceed with road test.

Frame Mounted: 3 Line Units

1.	Three line units, (with third line connected to master cylinder reservoir) can not be properly bled without a pressure bleeder.
2.	Set bleeder pressure at 50 to 60 psi. Be sure reservoir on master cylinder is filled above third line connection port.
3.	Do not run engine while bleeding.

Firewall Mounted (Push through boosters) All Makes.

1.	The bleeding procedure is essentially the same except that the engine should be running at the very beginning and throughout the entire process if a pressure bleeder is not used.

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