Motorcycle Fork Leaking Oil
Seal Leaking Fork Seals Yourself

If your motorcycle fork is leaking oil or the fork tubes are covered with oil, the cause is almost always aged or hardened fork seals. Over time, these seals lose their sealing ability. With LecWec, you can restore the sealing effect directly inside the system without immediately dismantling the fork.

✓Oil leak stop for leaking fork seals
✓Fast and reliable sealing effect
✓Oil sealing additive without chlorine
✓Seal the fork without dismantling

Order Now

How LecWec Works in Motorcycle Forks

Motorcycle forks use polymer seals and fork seals to keep the fork oil inside the system. Due to constant movement, pressure and temperature changes, these seals lose elasticity over time. The result: the sealing lip no longer sits properly against the fork tube and oil begins to leak. This is exactly where LecWec works during normal operation.

After being added, LecWec distributes through the fork oil and reaches the seals directly. The active ingredients are absorbed by the material and help the seals become flexible and tightly sealing once again. This closes the fine gaps between the fork seal and the fork tube directly at the sealing edge.

In practical use, this means that oil leaks at the fork are greatly reduced or stopped completely. Especially in cases of slightly leaking fork seals, LecWec restores the sealing function of the existing components without requiring the fork to be dismantled.

Only 3% of the total oil quantity.

LecWec is chlorine-free.

For all oil systems and types.

Direct delivery from the manufacturer.

It happened even faster than I expected.

"I have to report positively that the level matches the oil... unbelievable. [...] I wouldn’t have believed that the steering gearbox would be sealed again after just under a week."

Play video on YouTube.

By clicking play, you agree to YouTube’s privacy policy.

"...nothing was leaking anymore!!! I am truly very satisfied. At first, I did not believe the product would work, but now I am completely convinced and also saved many hundreds of euros!"
- Jürgen R.

Oil leak at the cylinder base gasket

Verified review (Learn more)

"I did not believe it at first, but your product is excellent! [...] I ordered just one can and everything is sealed already, even though you recommend 2 cans, meaning 200 ml, for 6 liters of oil. Many thanks!"
- Andreas F.

Oil leak problems at the oil flange gasket

Verified review (Learn more)

"...which made it even more satisfying when, after around 3 weeks, I noticed that the oil loss had gone down to zero – the steering rack was sealed again!! Even now, after 4 months, the reservoir is still at the maximum level."
- Friedger F.

Oil leak at the steering rack

Verified review (Learn more)

"There was always a small puddle of oil collecting underneath the vehicle. I added 100 ml of LecWec to around 4 liters of oil. Since then, I have driven many miles and was surprised to find that there was no more oil on the ground at all."
- Paul R.

Leak at the oil pan

Verified review (Learn more)

How to Seal a Motorcycle Fork in 3 Steps

If your fork is leaking oil, this is usually noticeable through an oil film on the fork tube or oil drops at the fork bottom. The cause is usually aged polymer shaft seals. Instead of dismantling the entire fork immediately, you can address the issue directly within the system and restore the seals to working condition.

Step 1: Clean the fork and check whether the oil leak originates directly from the shaft seal.
Step 2: Add LecWec to the fork oil at a ratio of 3% of the total oil volume.
Step 3: Move the motorcycle and compress the fork multiple times so the additive circulates throughout the system.

The shaft seals absorb the active formula, become flexible again, and fit tightly against the fork tube once more. This stops oil leaks at the critical sealing point. You avoid removing the fork and restore it to a sealed and fully operational condition quickly.

Motorcycle Fork Leaking Oil? These 5 Tips Can Help

Identify the exact leak location
Clean the fork tubes thoroughly and compress the fork several times. This allows you to determine whether the oil is leaking directly from the shaft seal or coming from above.

Keep the fork tube clean
Dirt, insect residue, or fine particles can damage the sealing lip. A clean surface prevents unnecessary wear on the shaft seal.

Check the surface for damage
Fine scratches or corrosion on the fork tube can prevent the seal from fitting properly. In such cases, the mechanical cause must be considered.

Restore seals directly
Shaft seals are made from polymer materials that harden over time. Through targeted treatment within the system, their elasticity can be restored.

Use LecWec correctly and monitor the result
Add LecWec to the fork oil at a ratio of 3% of the total oil volume and move the fork regularly. Afterwards, check the sealing performance. In many cases, the oil leak is significantly reduced or completely stopped.

Questions and Answers about LecWec

How Does LecWec Work?

Replacing a leaking oil seal is usually not an inexpensive repair. If an entire component needs to be replaced, the costs increase even further. Since 1995, however, “LecWec” has provided a permanent repair solution for polymer oil seals without disassembly or replacement, and without major time or repair costs. LecWec is not only effective for vehicles, but for all oil systems and all types of oil. Over time, polymer oil seals lose their plasticizers, become brittle, and shrink. LecWec impregnates the seal material and replaces the lost plasticizers. The seal becomes flexible again and expands slightly – exactly enough to compensate for wear at the sealing lip.

3How Much LecWec Do I Need for My Motorcycle Fork?

The required amount of LecWec depends on the oil volume inside the fork. The dosage is exactly 3% of the total oil volume. In a typical upside-down fork such as on a Yamaha R1, the oil volume per fork leg is usually between 400 ml and 600 ml. This means that approximately 12 ml to 18 ml of LecWec is required per fork leg. The additive is added directly to the fork oil. Through fork compression, LecWec circulates throughout the entire fork system and reaches the sealing edge of the shaft seal directly. This improves sealing performance exactly at the critical point without requiring fork disassembly.

4How Long Does It Take for LecWec to Work?

The effect begins as soon as LecWec circulates through the fork oil. Through compression and rebound movement, the active formula is transported to the sealing edge of the shaft seals and starts working there immediately. In practical use, initial improvements are often visible after a short riding time. Full sealing performance develops after several riding cycles, as the seals need time to absorb the active formula and regain their elasticity. Regular fork movement is essential for the process.

How Long Does the Effect of LecWec Last?

The effect of LecWec is designed for long-term sealing performance. Once the product has fully developed its effect, it usually remains effective for years. The requirement is that the product has enough time to circulate through the system during operation and fully interact with the seals. For this reason, the engine should run initially, after which LecWec continues working through normal operation and even during periods of inactivity. Depending on the seal material, this process can take anywhere from a few hours to several days. Once the full effect has developed, LecWec keeps the seals flexible and leak-free permanently without requiring regular reapplication.

3How Reliably Does LecWec Stop Oil Leaks?

LecWec stops oil leaks reliably and almost completely when the leak is caused by aged or hardened seals. The active formula circulates through the oil system and reaches all relevant sealing points. During operation, the seals absorb LecWec, become flexible again, and expand slightly. This allows them to fit tightly against the sealing surfaces once more and close the fine gaps through which oil previously escaped. Depending on the application, the effect begins within a few hours to several days and then remains stable over the long term.

3When Does LecWec Not Work?

The effect is limited on cork and paper gaskets. These rarely used materials can only absorb LecWec to a limited extent. In practical use, slight swelling may occur, which can reduce minor leaks. However, complete sealing of cork and paper gaskets cannot be achieved reliably. LecWec also does not work directly on metal gaskets, since these materials have no elasticity. If the oil leak is caused by adjacent polymer seals or minimal gaps, LecWec may still contribute indirectly to sealing the system.

Can I Use LecWec in the Fork and Engine at the Same Time?

Yes. LecWec can be used in different oil systems simultaneously. Engine, transmission, and fork are separate systems and each can be treated individually with the correct dosage.

3Do I Need to Disassemble My Motorcycle for the Application?

No. LecWec is added directly to the oil and works during normal operation. You do not need to open the fork, engine, or transmission of your motorcycle. This saves time and avoids unnecessary disassembly work.

Does LecWec Affect the Function of the Motorcycle Clutch?

No. LecWec does not change friction characteristics and has no negative effect on clutches, including wet clutches. Power transmission remains fully intact.

6Can LecWec Also Be Used Preventively?

Yes, LecWec can also be used preventively to keep seals flexible over the long term. Especially in machines with long periods of inactivity or high operating hours, the application helps prevent seals from drying out and becoming brittle. For preventive use, a reduced dosage of 1.5% of the total oil volume is recommended. This keeps the seals elastic and significantly reduces the risk of future leaks.

Can LecWec Damage the Engine or Transmission?

No. LecWec is developed to fully blend with the existing oil without affecting lubrication performance. It does not attack metal components and does not alter system tolerances. Bearings, gears, and other components remain completely unaffected. LecWec works exclusively on the seals within the system. When used correctly and at the proper dosage of 3% of the total oil volume, the application is safe and has no negative effect on the function of the engine, transmission, or hydraulic system.

8How Much Does LecWec Cost and Where Can I Buy It?

You can buy LecWec directly online in our online shop. There you will also find all current prices. Alternatively, you can send us a message below and we will gladly help you with your question or order.

+49 89 - 90 35 638

Monday - Friday
9:00 AM - 5:00 PM

order@lecwec.de

Motorcycle Fork Leaking Oil Seal Leaking Fork Seals Yourself

How LecWec Works in Motorcycle Forks

Only 3% of the total oil quantity.

LecWec is chlorine-free.

For all oil systems and types.

Direct delivery from the manufacturer.

It happened even faster than I expected.

How to Seal a Motorcycle Fork in 3 Steps

Motorcycle Fork Leaking Oil? These 5 Tips Can Help

Questions and Answers about LecWec

Motorcycle Fork Leaking Oil
Seal Leaking Fork Seals Yourself