adding, removing or replacing cat pads—torque hub type 5

___________________________________________________Operation ADDING, REMOVING, OR REPLACING CAT PADS – TORQUE HUB TYPE

During the lifetime of the BTP it will become necessary to replace damaged pads or even add or remove pads so that the proper crawler chain sag can be maintained without over stroking the tensioning cylinders. Follow the procedure below to safely and effectively add, remove or replace the cat pads.

1. Shut down the hydraulic power to the BTP (follow the “Shut Down

Procedure”). 2. Remove all bolts or clips from all of the top crawler covers and then remove all covers. If a broken pad needs to be replaced and it is not in visible site once the covers have been removed, re-power the

BTP (follow the “Start-up Procedure”). Stay clear of the crawler tracks. Raise up the BTP by using either the stab shoes, side-slew jacks, or crawler lift jacks (see the “Stab Shoe”, “Side-Slew”, or

Crawler Lift Jacks” sections). If the crawler lift jacks are used, the

BTP frame must have either crib blocks or some other means of support under it. This is so that the crawler lift jacks can be retracted to raise the crawlers up off of the ground so they can be operated without moving the entire BTP. 3. Operate the appropriate crawler track until the broken pad is visible and centered within the open covers on the topside of the crawler.

4. Once the pad is in position, release the tension from the grease take-up cylinder by bleeding off most or all of the grease within the cylinder (see the “Tensioning of the Crawler Pad Chains”).

Next all of the slack must be lifted to the topside of the crawler by either prying with a bar or hoisting with a come-a-long. A combination of both might be necessary so that a hook can be properly attached to the crawler pad chain. When all of the slack is on the top-side place several crib blocks under the crawler pad chain so that the area in which the chain will be broken is raised enough to be removed from the crawler track assembly. Next lower the crawler or BTP until both crawlers are in contact with the ground (see the “Stab Shoe”, “Side-Slew”, or Crawler Lift Jacks” sections).

Operation____________________________________________________

5. Remove both roll pins that retain the crawler pad attachment pin. Drive out the attachment pin thus breaking the cat pad chain.

REPLACING A BROKEN PAD:

To replace a broken pad, a second attachment pin must be removed so that the complete pad can be removed (follow the procedure in step five). Discard the broken pad and insert the new pad. If attachment pins or roll pins appear damaged or worn replace then before assembling.

ADDING A CRAWLER PAD:

To add a new pad just position it between the two disconnected sections and insert a new attachment pin along with two new roll pins. Once completed, the two disjointed sections can be reattached using the old attachment pin and roll pins. If attachment pin or roll pins appear damaged or worn replace then before assembling.

REMOVING A CRAWLER PAD:

To remove a pad, a second attachment pin must be driven out so that the complete pad can be removed (follow the procedure in step five). Discard or keep the removed pad as a spare if so desired. If attachment pins or roll pins appear damaged or worn replace then before assembling.

6. Remove all crib blocks or hoist from crawler pad chain. Next raise up the BTP by using the stab shoes, side-slew jacks or crawler lift jacks (see the “Stab Shoe”, “Side-Slew”, or “Crawler Lift Jacks” sections). If the crawler lift jacks are used, the BTP frame must have either crib blocks or some other means of support under it.

This allows the crawler lift jacks to be retracted and to raise the crawlers up off of the ground to measure the cat chain sag. Follow the section on “Tensioning of the Crawler Pad Chains”.

© DBT AUSTRALIA 2007