Hydraulic & Lube Oil Spin-On Filters – Models 25687534 & 23518532

Two robust spin-on cartridges designed for engine lube-oil and hydraulic auxiliary circuits on heavy-duty diesel platforms. 25687534 is a full-flow lube filter with a large canister (118 mm OD × 264 mm) and 1½-12 UN thread, while 23518532 is a shorter, wider canister (108 mm OD × 194 mm) with the same thread pitch, serving either lube or hydraulic return duty depending on head configuration. Both use cellulose media with resin-impregnated pleats for consistent efficiency across the service life.

Key Features

• 25687534: Full-flow lube, 22 μm nominal, SAE J1858 compliant, anti-drain-back valve, high dirt-holding capacity for extended oil-drain intervals

  
  

• 23518532: Dual-purpose lube/hydraulic, 18 μm nominal, 1½-12 UN thread, lower profile fits tighter engine bays or hydraulic tank-top heads

  
  

• Rolled carbon-steel shells with corrosion-resistant paint, zinc-plated end caps

  
  

• Integral bypass valve (per head design) and silicone anti-drain-back membrane on 25687534

  
  

• NBR gasket standard; FKM available for high-temperature or ester-fluid service

  
  

Technical Specifications

Application Guidance

25687534 – Primary full-flow lube filter on Series 60, 12.7L, 14.0L and similar heavy-duty diesel engines used in Class 8 trucks, generator sets, and marine propulsion. The 265 mm length provides ample media area for high-soot conditions and extended drain cycles (500+ hours typical). Often used in pairs on V-configuration engines.

23518532 – Shorter alternative for the same engine families where vertical clearance is restricted, or deployed as a hydraulic return-line filter on the same platform's auxiliary circuits (steering, fan drive, implement hydraulics). The 18 μm rating offers finer filtration than the 22 μm lube element, making it suitable for sensitive servo-valve systems.

Fluid Compatibility

• Mineral engine oil (API CK-4, CJ-4, FA-4)

  
  

• Mineral hydraulic oil (ISO HM, HV)

  
  

• Diesel fuel (for fuel-stage variants – confirm head compatibility)

  
  

• HFC water-glycol – NBR acceptable; FKM recommended for sustained use

  
  

• Not for phosphate ester (HFDR) without specific seal upgrade

  
  

Installation & Service

1. Clean filter head mounting face; inspect center tube and thread condition.

   
   

2. Lubricate new gasket with clean fluid, spin on by hand until gasket contacts head face, then tighten ¾–1 full turn. Do not overtighten – use hand force only.

   
   

3. For lube-oil duty: pre-fill canister with clean oil to reduce dry-start time.

   
   

4. Start engine and check for leaks at operating pressure and temperature.

   
   

5. Replace per OEM interval or when differential pressure indicates clogging (typically 2.5–3.0 bar bypass threshold).

   
   

Quality Assurance

Batch-tested to:

• SAE J1858 – filtration efficiency & capacity

  
  

• ISO 4548-12 – bypass valve characteristics (where applicable)

  
  

• ISO 3724 – flow fatigue resistance

  
  

• Shell burst test (minimum 4× working pressure)

  
  

Ordering

Quote 25687534 (118×265 mm, 22 μm lube) or 23518532 (107×195 mm, 18 μm dual-purpose) with quantity and seal material if non-standard. Cross-reference to common OEM numbers (Detroit Diesel, MTU, Perkins equivalents) available on request – provide your engine model and current part number for verification.

All values nominal; confirm thread, gasket dimensions, and pressure rating against your filter head before installation.