Here is a guide on how to repair brake cylinder for Yale forklift G807.The service brake pedal in the operator compartment actuates the master cylinder sending pressurized fluid to the brake pistons in the transaxles through the service brake lines.
1.Remove transaxle from lift truck. Remove parking brake and traction motor from transaxle. See section Remove Transaxle From Frame.
2.Drain oil from transaxle.
3.Remove snap ring in brake cylinder
Cover the cap with a cloth to control it in case it is ejected from the piston.
NOTE: Make note of the piston and cap orientation as well as the orientation of the seal on the piston before removal.
4.Direct pressurized air into service brake line port in cover to force cap out of cylinder. Recover spring from beneath cap. Remove seal from thecap and cut it in two to prevent accidental reuse.
5.Using a grind stone, slightly bevel the end of a 7/16 x 2 inch roll pin. Allow pin to cool.
6.Carefully position roll pin to piston. Drive roll-pin into cavity of piston with a nylon faced hammer.
NOTE: It may be helpful to apply compressed air to the service brake line port (as with removing the cap) AFTER the piston has been pulled to the top end of the brake cylinder.
NOTE: Make note of the piston and seal orientation during removal.
7.Pull roll-pin (and piston) from cylinder using pliers.
NOTE: Make note of the cylindrical pin orientation during removal.
8.Remove cylindrical pin from beneath piston.
9.Inspect cylinder walls for pits, cracks, and other damage.
NOTE: Install the cylindrical pin in the orientation noted during removal.
10.Lightly lubricate cylindrical pin with multipurpose grease and install into brake cylinder as noted during removal.
NOTE:A new brake piston and new seal should be used when repairing the brake cylinder assembly. Make sure the new piston and new seal are oriented as noted when removed.
11.Lightly lubricate new piston seal with multipurpose grease and install in new brake piston as noted during removal.
12.Install new brake piston (and seal) into brake cylinder.
13.Place spring into cavity in piston by hand.
14.Lightly lubricate new O-ring with multipurpose grease and install on cap as noted during removal.
NOTE: Make sure the cap is oriented as noted when removed.
15.Install cap into brake cylinder.
16.Press cap into cylinder, to expose snap ring groove,and install snap ring on brake piston.
NOTE: It is recommended to verify the torque on the transaxle cover capscrews before reinstalling the traction motor. See section Cover to Housing Seal.
17.Install brake and traction motor on transaxle and install transaxle on lift truck.
Make sure the lift truck is blocked at the same height as with the drive tire installed to ensure the proper fluid level reading.
18.Check transaxle fluid level. See section Fluid Level Check.
19.Install drive tire and tighten lugs to 170 N•m (125 lbf ft). Test lift truck for proper operation.
More repair case for Yale truck forklift,please refer to:YALE Forklift Trouble Repair.