Hyundai 59110-29000 Booster Assembly-Brake

For an operating check, step on the pedal and crank the engine; if the pedal sinks a little, then it is proper to use. Unrestrained, take the brake pedal down several times in turn with the engine running to check on the reserve distance. If the booster is all right for an airtightness check, begin the engine and stop after one or two minutes and step on the brake pedal gently several times; it it declines the first time, yet rises after the second or the third time, the booster is airtight. When the engine is running, apply the brake pedal and once the vehicle is stopped, turn off the engine when pressing the brake pedal; if there is no deflection in the reserve pedal travel of 30 seconds, the booster is finally airtight. A power brake booster unit is a very complicated component that should not be disassembled as it requires the use of special tools; the only recommended solution is to replace a defective unit with a new or remanufactured one. To detach the booster, first, unbolt the brake master cylinder, the vacuum supply line is to be disconnected from the booster, but should not be damaged. Find out and take off the pushrod clevis pin of the booster end so that it becomes separated from the brake pedal and, to do this, take out the retaining clip and, after that, pull the clevis pin out. The brake booster has four mounting nuts on the firewall, unfasten these nuts to free the setup, it may be rather dark in there. Sliding the booster to the right and backwards until the studs go over the holes, in like manner, slip it out from the engine compartment. Removal is to some extent the opposite of installation; fit new gaskets on both sides of the spacer at the firewall and tighten the nuts that hold the booster in place. In complicated models, if there is a new PB unit, the push rod clearance measurements should be taken from the master cylinder and the booster, assessing the pushrod clearance; it should be adjusted in the correct dimensions, if required. After the last fitting of the master cylinder, set the geometry for the brake pedal, adjust the freeplay and do some bleeding.

To check the brake booster for proper operation, perform a sequence of tests while sitting in the driver's seat. If the brakes do not normally operate during the tests, it indicates a brake booster failure. Further diagnosis and replacement may be necessary.