SWITCH GP-ROCKER 3264109 - Caterpillar

sealing probe adapters are designed to be used in situations that require the temperature of a captive fluid (gas or liquid) to be measured without stopping the machine or draining the system. The self sealing probe adapters are available in three configurations: 5P2720-1/8"-27 NPT, 5P2725-1/4"-18 NPT and 5P3591-9/16" straight thread with O-ring seal.
The probe adapters are to be used with 1/8" diameter probes only. Some earlier probes had a 3/16" diameter shoulder near the thread area. These probes should not be installed into a probe adapter. The probe adapters are designed to be used at a temperature NOT to exceed 130°C (266°F) and at a pressure NOT to exceed 3100 kPa (450 psi). The probe MUST be clean, smooth and lubricated with a petroleum jelly prior to being inserted into the probe adapter. It is not generally necessary to tighten the probe with a wrench. However, if a wrench is used, tighten only enough to hold the probe in place. The seal takes place within the adapter not at the probe threads.
To help ensure that the self sealing probe adapter seals when a probe is being installed or removed, use the following procedure.
Installation Of Self-Sealing Probe Adapter
1. The earlier probe adapter had flats on the seal retainer. The current seal retainer does NOT have flats on it. The flats were removed to help prevent accidental removal of the seal retainer. The seal retainer is installed during assembly with a thread lock material and tightened to a specific torque. Prior to installation, check probe adapters for a loose seal retainer by removing the plug. The seal retainer should not move as the plug is removed. DO NOT use adapters that have a loose retainer. Do not attempt to retighten a seal retainer that has come loose because the seal between the seal retainer and bladder will be damaged.2. The seal bladder is punctured during manufacturing with a sharp instrument. Make sure that the seal bladder has been prepunctured before installation by lubricating a clean, smooth probe and inserting the probe into the adapter. Look at the bladder while inserting the probe. A prepunctured bladder will have an obvious opening on the surface and very little force will be required to insert the probe through the bladder. DO NOT use an adapter that has NOT been prepunctured. Do not attempt to puncture a bladder that has not been prepunctured. To do so may damage the seal between the seal retainer and the bladder and also tear the bladder which will cause the adapter to leak when it is installed.3. Remove the probe and reinstall the plug. Tighten the plug enough to hold it in place.4. Install the probe adapter on the machine. This should be done while the machine is shut down, cool and the system is relieved of any pressure. It may be necessary to drain liquids prior to drilling and tapping a point of access. Probe Installation
1. With the machine either operating or shut down, remove the cap