TSL (Throat Seal Liquid) is for contractor-grade Graco sprayers (390, 395, 490, 495, Mark series) — used to lubricate packings during and between uses. Pump Armor is for Magnum homeowner sprayers (X5, X7, ProX17) — used to protect the pump during long-term storage. Using the wrong fluid can damage packings. If you have a contractor machine, always use TSL. If you have a Magnum and you're storing it for more than a few days, use Pump Armor.
1. The Core Difference in One Sentence
TSL lubricates packings during use. Pump Armor protects the pump during storage. They are not interchangeable, and using the wrong one in your machine is one of the most common causes of premature packing failure we see at SprayersParts.
2. What Is Graco TSL (Throat Seal Liquid)?
Throat Seal Liquid is a mineral oil-based fluid specifically formulated to lubricate the packing area (throat) of Graco contractor airless sprayers. The throat area surrounds the displacement rod — the reciprocating metal rod that drives the pump piston. Without adequate lubrication, the packings that seal this area wear rapidly, leading to pressure loss and paint leaking down the rod.
TSL is used in two ways:
- During operation: Keep the throat cup filled with TSL at all times when spraying. Check and top up before every job.
- During packing installation: Apply TSL to new packings before installing them, and fill the throat cup after assembly.
Pro tip: Check the TSL level in the throat cup every morning before starting a job. A consistently low level is often the first sign that packings are wearing and need attention.
3. What Is Graco Pump Armor?
Pump Armor is a water-based storage fluid designed to protect the internal pump components of Graco Magnum homeowner sprayers during storage. It contains corrosion inhibitors and antifreeze properties to prevent rust and seal damage when the machine sits unused for weeks or months.
When you finish a painting project with a Magnum X5 or X7, flush the pump with water, then run Pump Armor through the system. This leaves a protective coating inside the pump that preserves the seals and prevents corrosion until your next use.
Do not use Pump Armor as a packing lubricant during operation. It is not designed for this purpose and will not protect packings the way TSL does. Using Pump Armor in the throat of a contractor machine during spraying can lead to accelerated packing wear.
4. Side-by-Side Comparison
| Property | TSL | Pump Armor |
|---|---|---|
| Primary purpose | Packing lubrication during use | Pump protection during storage |
| Base fluid | Mineral oil | Water-based / antifreeze |
| Machine type | Contractor sprayers | Magnum homeowner sprayers |
| Use frequency | Every job, every day | End of season / long storage |
| Freezing protection | No | Yes |
| Suitable for packing area | Yes — primary use | No — storage only |
| Water-based paint compatible | Yes | Yes |
| Oil-based paint compatible | Yes | No |
5. Which Machine Needs Which Fluid?
Graco 395 PC
Graco 490 PC / 495 PC
Graco Mark IV / Mark V
Graco Ultra 395 / 495 / 595
Graco LineLazer 3400
Graco Pro 210 ES
Graco Magnum X7
Graco Magnum ProX17
Graco Magnum ProX19
Graco TrueCoat series
Use TSL for throat lubrication during use
6. What Happens If You Use the Wrong Fluid?
Using Pump Armor instead of TSL in a contractor machine is one of the most common service mistakes we encounter. Here's what happens:
- Packings dry out faster: Pump Armor doesn't provide the same ongoing lubrication that TSL does, leading to accelerated packing wear
- Pressure loss sooner than expected: New packings that should last 12 months may fail in 3–4 months if TSL isn't used
- Voided warranty situations: Using incorrect fluids is a common reason for warranty claim denial
Using TSL in a Magnum sprayer for long-term storage is less harmful, but Pump Armor is still the correct product — it contains antifreeze protection and corrosion inhibitors that TSL does not.
Shop TSL & Pump Armor
Both in stock. Ships same day from Houston, TX. Free shipping on orders over $99.
7. Frequently Asked Questions
Pro tip: Fill the TSL cup every day before you start spraying and again before you shut down. A steady TSL level costs pennies — new packings cost over $100.
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