Lubricate Brake Components and Check Camshaft Support
- Locate and lubricate camshaft-support bushings to the stated endpoint.
- Recognize camshaft movement that warrants bushing inspection.
- Resolve lubricant conflicts before servicing brake components.
- Grease gun — Deliver confirmed approved grease through the spider and camshaft-support fittings.
- Shop rags — Clean fittings before lubrication and remove expelled grease without spreading it onto friction surfaces.
- Inspection light — Illuminate fittings, bushing seals, and camshaft supports.
- Inspection mirror — Observe grease emerging beyond seals where direct visibility is limited.
- Small lubricant brush — Apply high-temperature anti-seize grease to exposed roller journals and anchor pins during service while keeping friction surfaces clean.
Camshaft bushings are lubricated through fittings at the brake spider and camshaft support bracket. Apply enough approved grease to become visible beyond the bushing seals rather than continuing without an observable endpoint.
During lubrication, the source recommends shaking the camshaft to check for excessive clearance caused by bushing wear. This inspection connects lubrication work with assessment of the camshaft's mechanical support.
Camshaft roller journals and brake anchor pins receive high-temperature anti-seize grease during disassembly, maintenance and reassembly. These locations must not be confused with slack-adjuster lubrication requirements.
The supplied page contains differing grease guidance: its prose specifies Dexter's lithium-base NLGI Grade 1 anti-wear grease with rust and oxidation additives, while its illustration labels manual adjusters and spider/support bushings NLGI Grade 2 and directs automatic-adjuster lubrication to the adjuster manufacturer. It gives an interval of 3–6 months or 50,000 miles, or the adjuster manufacturer's recommendation. Values vary by maker; resolve the applicable lubricant and interval rather than treating these conflicting labels as interchangeable.
How It Works
Lubrication with an observable endpoint
Camshaft bushings receive grease through fittings at the brake spider and camshaft support bracket; apply approved grease until it becomes visible beyond the bushing seals. Lubricant separates moving surfaces and helps limit wear, but continued pumping without observing the seals does not establish that grease has reached the intended area. Keep expelled lubricant away from brake friction surfaces.
Lubrication is also a support inspection
Shake the camshaft during lubrication to check for excessive clearance associated with bushing wear. Worn support bushings allow unwanted shaft movement and can impair consistent brake motion; fresh grease does not restore worn mechanical support. The lesson supplies no numerical clearance limit, so suspected wear requires confirmation against applicable service guidance.
Resolve lubricant and interval conflicts
The prose specifies Dexter's lithium-base NLGI Grade 1 anti-wear grease with rust and oxidation additives, while the illustration specifies NLGI Grade 2 for manual adjusters and spider/support bushings and refers automatic-adjuster lubrication to the adjuster manufacturer. The supplied interval is 3–6 months or 50,000 miles, or the adjuster manufacturer's recommendation; confirm the applicable lubricant and interval rather than treating conflicting guidance as interchangeable. Roller journals and brake anchor pins receive high-temperature anti-seize grease during disassembly, maintenance and reassembly, which is distinct from slack-adjuster lubrication.
Step-by-Step Procedure
0/6 doneDiagnostic Chart
| Symptom | Check | Spec / Expected | Likely cause & fix |
|---|---|---|---|
| Grease does not become visible beyond the bushing seals. | Confirm that the correct fitting is being serviced and observe the seal area with a light and mirror; stop and investigate delivery if the endpoint cannot be verified. | Apply enough approved grease to become visible beyond the bushing seals. | An obscured seal area, blocked fitting or passage, or poor grease-gun connection may prevent observation or delivery. Basis: 9-15k complete service manual |
| The camshaft has noticeable movement when shaken. | Observe movement at the spider and support bushings while shaking the camshaft; assess suspected excessive clearance using applicable component service guidance. | Check for excessive bushing clearance; the lesson provides no numerical acceptance limit. | Bushing wear may have reduced camshaft support; lubrication cannot correct lost material. Basis: 9-15k complete service manual |
| Available lubrication instructions disagree. | Identify the installed components and reconcile the source prose, illustration, and applicable manufacturer guidance before selecting lubricant or interval. | Prose: NLGI Grade 1. Illustration: NLGI Grade 2 for manual adjusters and spider/support bushings. Automatic adjusters: follow adjuster manufacturer guidance. | The supplied source contains differing grease guidance that cannot safely be treated as interchangeable. Basis: 9-15k complete service manual |
| Lubricant is found on brake friction surfaces. | Stop service, identify the contamination path, and consult applicable brake service guidance for corrective action before returning the trailer to service. | Keep lubricant off brake friction surfaces. | Careless application or transfer from greasy tools, hands, or rags can contaminate friction material and reduce braking effectiveness. Basis: General shop practice |
At the Bay: Diagnose the Case
CASE 1 / 4
Grease does not become visible beyond the bushing seals.
- Test
- Compare
- Correct
Select the next check
Basis: 9-15k complete service manual. A likely cause is a hypothesis; confirm it with the applicable service procedure before repair.
Common Bay Mistakes
- ✕ Assuming the conflicting grease grades are interchangeable.
- ✕ Pumping blindly instead of watching for grease beyond the seals.
- ✕ Treating fresh grease as a repair for worn bushings.
- ✕ Using roller-journal anti-seize guidance as slack-adjuster guidance.
Quick Check
Practice only — not scored.
Plan the Service Sequence
Planning practice only. Follow the applicable manufacturer's instructions, employer safety program and qualified supervision on real equipment.
Plan the first action. Compare the service steps with the bay mistakes.
Hands-on: Shop Test Equipment
Air Brake Board — Leakdown & Pushrod Stroke
Supply and service gauges, gladhand controls, pushrod stroke ruler (Type 30 chamber)
🛠 Equip your bay for this test →Symptom: Pre-trip inspection.
Spec limits used
- 2 in — Type 30 max pushrod stroke (Dexter 9-15K service manual, p.52)
- 80–90 psi — Adjustment test application pressure (Dexter 9-15K service manual, p.51)
- 130 psi — Never exceed (chamber failure risk) (Dexter 9-15K service manual, p.51)
- illustrative only — Leakdown pass limit (General shop practice)
Simulated readings for practice. Always follow the manufacturer's procedure and values on a real trailer.
Source: 9-15k complete service manual — 47