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Filling and Bleeding the System

Filling the System

1. Verify that all sender arms are free to traverse their complete arc.

2. Verify that all bleeder valves on the throttle and clutch slaves are closed, and linkages disconnected.

See section on System Fluid for fluid specifications.

3. Remove fill port plug from the reservoir and fill the reservoir within one inch of the top of the sight tube with MCO-03 water glycol fluid. Replace fill port plug.

4. Pressurize reservoir to 100 +/- 10 psi through the air filter valve in the top of the reservoir.

5. The system will now begin to fill with fluid. As the system fills the fluid level in the reservoir will become lower. When the fluid level is between 1 to 2 inches from the bottom of the sight glass release the pressure and refill the tank, as in Step 4.

6. Repressurize the system and repeat this procedure of filling the reservoir as required until no fluid drop is noted. At this point, the system is filled and must now be bled.

Bleeding the System at Slave

The bleeding procedure is much easier for two people to perform than one. (One to keep the reservoir filled and pressurized, while the other one bleeds the system.)

1. Fill the reservoir as required.

Verify that linkage is disconnected, and sender's handles are free to move.

While bleeding, move the slave arm and verify that the piston has bottomed.

2. Using the bleeder tube provided and a clean, empty container, insert the bleeder tube in the bleeder valve at one side of a slave. Open the bleeder valve about one turn and bleed system until no air bubbles are evident in the flowing fluid. When the fluid is clear, close the bleeder valve. During the bleed operation maintain the system pressure above 60 psi, and the fluid level in the sight gauge above the two-inch mark. Should the fluid level drop below the two-inch mark, close the bleeder valve and release the pressure from the reservoir with the fluid that has been bled off and repressurize. Continue bleeding from the same bleeder until no air or foam are evident in the fluid. Draw at least a full reservoir of fluid thru each side of each circuit.

Since there are two positions at each slave to be bled and four slaves, the reservoir must be filled at least 8 times during the bleed operation. The fluid which has been bled off should be used to refill the reservoir.

3. Tighten bleeder valve after the bleed operation.

4. Bleed the second port of the slave as described in Steps 1, 2, and 3.

5. Repeat steps 1 thru 4 with a second person at the sender moving the handles back and forth slowly five to ten times.

6. Continue performing the preceding five steps for each remaining slave.

Bleeding the System at Senders

After the slaves have been bled, a small amount of air will still be trapped at the high point of each sender head. This air must be eliminated.

1. Refill reservoir if required (fill tank at this time to between 1/2 and 2/3 full), and leave about 100 psi on the pressure gauge.

Place a rag over the bleeder hole on the sender, to prevent fluid from spilling on the console.

2. Very slowly open the bleeder screw using a 3/16" allen wrench. See Figure 14 for location of bleeder screw.

Figure 14. Bleeder Screw on Sender Body

3. Allow the fluid to bleed out until the fluid is clear without air bubbles.

4. Tighten the bleeder screw after bleeding.

5. Repeat Steps 1 to 4 above, for each sender.

6. The reservoir level should be between 1/2 and 2/3 full. If the level is below this, the reservoir is between 80 and 85 psi.

The fluid recommended for use in the system is a 50/50 mixture by volume of distilled water and ethylene glycol. The type of ethylene glycol used is very important for proper operation of your system. Some additives, especially silicone additives, are very thick in consistency and will clog the critical components in the system. If this occurs in your system you will be unable to maintain synchronization between sender and slave.

The ethylene glycol chosen for use should be as pure (no additives) as possible, proportionately mixed with distilled water then filtered to assure its purity. NEVER USE STOP-LEAK TYPE ANTI-FREEZE.

Filtration is accomplished by passing the fluid through a 5 micron filter before using in the system.

Field service pre-filtering can be accomplished by using a "Mr. Coffee" or equivalent paper filter placed in a funnel and then pouring the ethylene glycol solution through it.

One paper filter will handle approximately one quart of ethylene glycol solution.

The MCO-03 fluid available from Hynautic is proportionally mixed and filtered to assure its purity and is ready for use.