ATHENA Fork Oil Seal Kit 30x40.5x10.5 mm for SUZUKI RM, TS 100, 125, 185 and YAMAHA DT, TY, YZ 80, 100, 125, 175 1971-1983

The ATHENA 30x40.5x10.5 mm P40FORK455012 fork oil seal kit is designed for YAMAHA DT 80, DT 100, DT 125, TY 175, YZ 125 and SUZUKI RM 100, TS 125, TS 185 from 1971 to 1983. Fitted at the top of the fork leg, under the dust seal, the oil seal keeps the fork sealed. A leak lowers the oil level, the damping changes and oil can run onto the brake disc.

Specifications

• Brand: ATHENA
• Manufacturer part number: P40FORK455012
• EAN code: 8055681307940
• Weight: 40 g

When to replace it?

• Film of oil on the inner tube after a few fork strokes.
• Oil traces on the fork leg, the caliper or the brake disc.
• Fork that becomes softer on one side.

Before replacing a leaking seal, clean under its lip: a trapped grain of sand is sometimes enough to cause the leak. If it still leaks, replace the seals on both legs. Measure your seal (inside diameter, outside diameter and height) or check the original part number: the size is in the name.

Fitting tips

1. Drain and disassemble the fork leg following the manual, then remove the dust seal, the circlip and the old seal.
2. Check the fork bushings and the condition of the inner tube: a scratch or a rust spot will cut a new seal.
3. Protect the end of the tube (plastic bag), oil the lip and drive the seal in straight with a seal driver of the right diameter.
4. Refit the circlip and a new dust seal, then reset the fork oil level.

Why ATHENA?

Founded in 1973 near Vicenza, Athena is an Italian engine gasket specialist that has made its gaskets on its own production lines since day one, as well as a renowned manufacturer of pistons and cylinder kits. The brand supplies original equipment to manufacturers such as KTM, Ducati, Fantic, Piaggio and Triumph, and is a partner of the MXGP motocross world championship.

Spare parts and items to plan

• Fork dust seals : ATHENA P40FORK455131 · ATHENA P40FORK455099
• Fork oil : LIQUI MOLY 10W 500 ml
• Fork bushings : SKF · INNTECK

Frequently asked questions

Do I have to change both seals?
Yes: they have the same age and the same mileage. Replace both oil seals and, ideally, both dust seals.

Why is my new seal leaking?
Most often because of a scratched or pitted tube, a lip turned back during installation, or worn bushings that let the tube develop play.

Compatibility

Check the exact model and year of your bike in the list below before ordering.

Fits:
SUZUKI RM 100 1978
SUZUKI RM 100 1977
SUZUKI RM 100 1976
SUZUKI TS 125 1977
SUZUKI TS 125 1976
SUZUKI TS 125 1975
SUZUKI TS 125 1974
SUZUKI TS 125 1973
SUZUKI TS 125 1972
SUZUKI TS 125 1971
SUZUKI TS 185 1978
SUZUKI TS 185 1977
SUZUKI TS 185 1976
SUZUKI TS 185 1975
SUZUKI TS 185 1974
SUZUKI TS 185 1973
SUZUKI TS 185 1972
SUZUKI TS 185 1971
YAMAHA DT 80 1983
YAMAHA DT 80 1982
YAMAHA DT 80 1981
YAMAHA DT 100 1976
YAMAHA DT 100 1975
YAMAHA DT 100 1974
YAMAHA DT 125 1976
YAMAHA DT 125 1975
YAMAHA DT 125 1974
YAMAHA TY 175 1976
YAMAHA TY 175 1975
YAMAHA YZ 125 1975
YAMAHA YZ 125 1974