The term “blown fork seal” is often heard around the track concerning the puddle of oil on the ground below the front fork. According to our Lead Tech, Red Wiley, this term is misrepresentative of the actual problem. Red says, “many riders see that puddle and jump to replacing the fork seals. Sure, this fixes the problem, but it might not save your weekend.”
Leaking forks are typically caused when dirt and debris make it past the scraper and is pushed between the fork tube and the seal. This creates a path of escape and results in a puddle.
The presence of dirt on the fork isn’t uncommon – after all, it is a dirt bike in its natural habitat. But a dirty, oily fork tube isn’t just the problem, it’s the cause. The fork is an often-overlooked point in the pre-ride checklist and simply cleaning the tubes before a ride can prevent contaminants from entering the seal and causing the leak.
If and when the seal is contaminated you’ll notice a ring of oil around the fork tube and likely some accumulated dirt. It is important to note that we are advocates for periodical fork maintenance and service, but when you’re in a pinch and your seals are leaking, here is how to clean out the seals without tearing the fork apart and replacing them:
Step 1: Wipe the fork tube down with contact cleaner and a rag to remove debris from the surface.
Step 2: Use a flat head screw driver to pull the seal scraper down. (The seal scraper is the first line of defense for the actual seal). Slide this scraper to the bottom of the fork tube to get it out of your way when cleaning the seal. Spray cleaner around the seal to flush out debris, then wipe clean.
Step 3a: Find something thin and rigid that will fit between the seal and fork tube. Note: things like tear-offs, water bottles and camera film work well. We do not recommend using metal feeler gauges as they run the risk of cutting the seal.
We prefer to use a product called Seal Doctor by Risk Racing. It costs about $24 and comes in a couple sizes. This product is designed to snap around the fork tube and be twisted around the tube under the seal to pull out debris. While the aforementioned homemade remedies can be difficult to handle, the Seal Doctor makes cleaning the seal simple and painless.
Step 3b: Push your chosen tool between the seal and tube. Work the tool around the tube, pulling out debris as you go. It is necessary to use a cleaning spray to flush out debris as well as provide lubrication for the tool and the seal. (Refrain from using contact cleaner or carb cleaner for this job as it evaporates too quickly and dries the surface out. We like Bel-Ray’s 6-in-1 for this job). Repeat this step until the seal is cleaned of debris. You may need to compress and release the front forks by holding the front brake and pumping down several times to ensure the seal is clean.
Step 4: If using a Seal Doctor, use the bottom portion of the tool to clean out the seal scraper. If using an alternative, remove and flush the debris from the scraper.
Step 5: Once everything is cleaned, reinstall the scraper by pushing it back into place.
NOTE: We are advocates for preventative maintenance. Forks should be serviced regularly and seals, bushings, oil and other suspension parts should be serviced and or replaced when necessary.