INSERT 3904968 - Caterpillar

Illustration 1. New couplers and nipples for hydraulic test equipment.The new couplers have a lock-back design which makes them easier to connect. The sleeve on the coupler stays in the lock-back position until it engages a nipple. The sleeve then releases and moves forward to the connected position. During installation the sleeve on the former couplers had to be held back by hand in the release position. This made it much more difficult to work with them. The new couplers also have a longer sleeve than the former ones which makes it easier to release them. See Illustration 2. The new couplers and nipples are silver in color while the former ones are gold in color. The new and former parts are rated at the same 41,500 kPa (6000 psi) operating pressure.
Illustration 2. New design and former design of couplers and nipples.The new couplers and nipples are direct replacements for the former couplers and nipples when the new ones are used together. The new couplers and nipples can not be used with the former couplers and nipples.
The new couplers and nipples along with their thread size and type are shown in the chart.
The part numbers of three groups have changed because of the new couplers and nipples included in them. The new and former groups are shown in the chart.