Assembly Paste

Where assembly paste belongs in your maintenance routine

Assembly paste is for preventing bolts, studs, and contact surfaces from seizing after assembly. You apply it once at the moment of fitting, and it protects for the service life of that component. It is not a lubricant for moving or rotating parts, and it has no effect on combustion, oil quality, or engine performance. Its compatibility depends on the materials and temperatures involved, not on whether your car runs on petrol, diesel, or E10.

This is a product for careful DIY use, not an exclusively professional tool. If you are doing any of the following jobs at home, assembly paste belongs in the process:

• Seasonal tyre swap: a thin film on the wheel hub face stops the wheel from sticking to the hub after a winter of road salt and moisture.
• DIY brake pad or disc replacement: applied to guide pins and the pad contact points in the carrier, it reduces corrosion and squeak at those surfaces. Never on friction surfaces.
• Exhaust repair or clamp replacement: exhaust bolts and clamps are exposed to extreme heat and corrosion; paste applied at fitting makes future removal realistic rather than a fight.
• Bike maintenance: pedal threads, metal seatposts, and bottom bracket cups all benefit from a thin film to prevent seizing in the frame or crank. Note that carbon seatposts and handlebars require a dedicated carbon assembly paste with friction additives, which is a different product.
• First-time DIY assembly: if you are fitting a component and already thinking about how hard it will be to remove in two years, assembly paste is the right answer at this stage.

Where to use it on your car, and where not to

The most common mistake with assembly paste is applying it in the wrong place. The list below gives you a clear reference before you start.

Yes, use it here:

• Wheel hub face (between hub and alloy wheel), to prevent the wheel from bonding to the hub over winter
• Exhaust bolts, studs, and clamp threads, where heat and corrosion make future removal difficult
• Brake pad contact points: the pad ears where they slide in the carrier, and the back of the pad where it contacts the caliper bracket
• Brake caliper guide pins, provided the paste is compatible with the rubber boots on those pins
• Lambda and oxygen sensor threads, but only with a ceramic or metal-free paste, not a copper-based one
• Spark plug threads in aluminium cylinder heads, only if your manufacturer allows it and only in a very thin film; check your workshop manual first
• Bike pedal threads, metal seatposts, and bottom bracket cups

No, not here:

• Brake discs and pad friction surfaces: never, under any circumstances
• Wheel bolt threads and seating surfaces if your vehicle manufacturer specifies dry threads; do not override that instruction
• Torque-critical structural fasteners such as head bolts, suspension wishbones, tie rods, and subframe bolts, unless the OEM explicitly allows and specifies a lubricant
• Internal engine or gearbox components; assembly paste is not a circulating lubricant
• Carbon fibre seatposts and handlebars; these require a carbon-specific paste with friction additives, not a standard anti-seize product

One important point that applies across all of the above: assembly paste changes the friction at the thread and contact surface, which means torque and clamping force change too. Manufacturer torque specifications are set for a defined condition, whether that is dry, lightly oiled, or a specific product. If you apply paste where the manual says dry, you risk over-tightening without realising it. For wheel bolts and other safety-critical fasteners, always follow the workshop manual. Using paste where it is forbidden can affect braking performance, wheel retention, and in some cases your warranty or MOT result.

Does using assembly paste change the torque you need to apply?

Yes, it can, and this is the detail that matters most for safety-critical fasteners. A thin film of assembly paste reduces friction in the thread and under the bolt head or nut. With lower friction, the same torque wrench setting produces a higher clamping force than it would on a dry thread. That means you can unknowingly overtighten a bolt while the wrench clicks at the right value.

OEM torque specifications are nearly always based on a defined friction condition. For most wheel bolts, that condition is dry or at most very lightly oiled, not pasted. If you apply assembly paste to wheel bolts on a car where the manufacturer specifies dry threads, you are no longer tightening to the correct clamping force, even if your torque wrench says otherwise. Some manufacturers do allow a specific lubricant on certain fasteners and may give a different torque figure for that condition. The only way to know is to check your workshop manual or the manufacturer's technical documentation for that component.

For your APK or MOT, and for warranty purposes, the paste itself is not the issue. What matters is whether you followed the manufacturer's instructions. If the manual permits lubrication and you have applied it correctly, there is no problem. If the manual requires dry threads and you have added paste, you have deviated from the specification, with potential consequences for safety and liability. When in doubt, leave the paste off torque-critical fasteners and consult a garage.

Which type of assembly paste is right for your situation

Not all assembly pastes are the same. The main differences lie in the additive system and the temperature range each type is suited to.

For most modern cars with ABS, alloy wheels, and temperature sensors, a ceramic or metal-free assembly paste is generally the safer default. Metal-based pastes such as copper or nickel variants perform well at high temperatures, but they are typically electrically conductive and can cause galvanic corrosion on aluminium components over time. That combination makes them a less suitable choice near sensors or on the aluminium-to-steel interfaces common on modern wheels and hubs. For exotic alloy components such as magnesium housings or specialist lightweight structures, follow the manufacturer's recommendation or ask a garage before applying any paste.

For most DIY tyre swaps, brake work, exhaust bolts, and bike maintenance, a single high-quality assembly paste such as Lindemann MP790 Assembly Paste 250gr is sufficient, provided you follow the "where to use it" guidelines above.

How to apply it correctly, and how often

Application is straightforward, but the amount matters. Follow these steps:

1. Clean the parts first. Remove old paste, grease, and loose rust with a cloth and a suitable cleaner. The surface should be clean and dry before you apply anything new.
2. Apply a thin, even film. Use a small brush or a fingertip to coat the threads or contact surface lightly. You should still be able to see the shape of the metal underneath. No thick blobs, no pooling.
3. Apply only to the intended surfaces. On bolts, coat the thread spiral and the seating surface. Keep paste away from the bolt head and away from any friction surface such as brake discs or pad faces.
4. Assemble and tighten to the correct torque. Fit the parts and use a torque wrench wherever the manufacturer gives a torque value. Remember that paste changes friction, so follow OEM guidance on whether lubrication is permitted.
5. Wipe off any excess. Remove visible surplus from surrounding areas. Excess paste can collect brake dust and road dirt, which builds up over time and can cause noise or uneven contact at brake components.

You reapply assembly paste each time you disassemble and refit the part. There is no fixed mileage or time interval. For wheels and hubs, that means once per tyre change season when you remove the wheel. Quality paste is designed to stay in place rather than dry out or wash away quickly, but in exposed areas some paste can gradually be displaced, which is another reason to reapply at each disassembly.

If a bolt is already heavily rusted or seized, assembly paste is too late. You need penetrating oil, appropriate tools, or professional help first. One more boundary worth noting: threadlocker and assembly paste are opposites. One locks bolts in place; the other makes removal easier. Never substitute one for the other.

When to let a garage handle it instead

Most seasonal tyre swaps and straightforward brake pad replacements are well within reach for a careful DIY mechanic. Some tasks, however, carry enough risk from incorrect torque or paste application to make professional help the sensible choice.

Consider a garage for:

• Brake caliper mounting bolts and brackets: safety-critical; torque and paste rules must follow OEM exactly.
• Suspension and steering fasteners such as wishbones, tie rods, and subframe bolts: high structural loads mean DIY is only appropriate if you fully understand the manufacturer's procedure and torque specifications.
• Spark plugs and sensor threads on modern engines: if you are unsure whether anti-seize is permitted or what torque value applies, let a garage handle it.
• Heavily rusted or seized bolts and studs: freeing them typically requires penetrating oil, heat, or extraction tools. Paste does not help once a bolt is stuck.
• Exotic or mixed-alloy components such as magnesium structures or carbon composite with metal inserts: the wrong paste can cause corrosion or structural damage; a specialist is the right call.

If you are unsure whether a specific fastener on your car falls into one of these categories, the packaging of the Lindemann MP790 Assembly Paste 250gr gives guidance on suitable applications, and your workshop manual is always the definitive reference for torque and lubrication rules.