Description
Quality replacement oil-coalescing air dryer assembly for trucks originally fitted with the Meritor WABCO System Saver 1200UP. Supplied as a complete 12-volt unit with the coalescing desiccant cartridge installed. This is a new assembly, not a remanufactured exchange unit, so there is no core charge.
Signs You Need a New Air Dryer
- Water or grey oily sludge draining from the wet tank – the clearest sign a coalescing cartridge is saturated
- Continuous air leak or hiss from the purge valve, either while the compressor is loaded or through the whole unload cycle
- No purge blast at governor cut-out – the desiccant is no longer being regenerated
- Slow air build-up and a compressor that runs almost constantly, from a plugged or iced cartridge
- Truck builds air normally in mild weather but will not build at all below freezing – failed heater or thermostat
- Purge valve spitting far more often than normal, often a leaking outlet check valve at Port 21
- Contaminated brake valves, ABS faults or frozen air lines downstream
Specifications
| Manufacturer | Predator HD |
|---|---|
| Part Number | R955082 |
| Type | System Saver 1200UP, oil-coalescing |
| Voltage | 12 V DC |
| Heater | 100 W – thermostat on at 45 F, off at 86 F |
| Heater Resistance (12 V) | 1.0 – 2.0 ohms |
| Purge Tank | Required – external, plumbed to Port 22 |
| Port 1 (supply) | 1/2 in – 14 NPTF |
| Port 21 (delivery) | 1/2 in – 14 NPTF, contains check valve |
| Port 4 (governor) | 1/4 in – 18 NPTF |
| Port 22 (purge tank) | 1/4 in – 18 NPTF |
| Max Operating Pressure | 140 psi |
| Desiccant Volume | 1200 cc |
| Cartridge Included | Yes – oil-coalescing |
| Mounting Torque | 22 – 30 lb-ft |
| Weight | Approx. 9 – 10 lb |
| Condition | New – no core charge |
Cross References
This part replaces or is equivalent to the following part numbers:
- Meritor: R955082
- WABCO / ZF (current number): 4324210330, S432 421 033 0
- Volvo: 85122949, 20935355
- Mack: 23036575, 6300-4324210330
- Freightliner: TDA R955082, TDAS4324210330
- Kenworth / Peterbilt: S432-421-033-0
- Automann: 170.955082
- Newstar: S-28164
- World American: WAR955082
Applications
This air dryer fits trucks originally equipped with the Meritor WABCO System Saver 1200UP oil-coalescing dryer, including Volvo, Mack, Freightliner, Western Star, Kenworth and Peterbilt applications.
Model-year coverage is not published by the manufacturer – verify against the number on the dryer you are removing, or by VIN. The UP suffix means this dryer uses a separate purge tank plumbed to Port 22 and the compressor discharge line for unloading; if your truck has no purge tank you need the 1200U version (R955210), and if it has a purge tank but no unloader line you need the 1200P coalescing version (R955079). Replace the coalescing cartridge every one to two years – Meritor R950068A, now WABCO 4329012482.
