M1513

2020-03-26

M1513: DIAGNOSTICS AND REPAIR - LEAKS, WEEPS AND SEEPS
• Leaks from the inside diameter past the lip.

Reason for Revision

• Leaks from the outside diameter between the seal and the
bore it is mounted in.

Refer to Table 1.

Inside Diameter

Table 1. Document History
Date

Revision Description
Sealant removal and typo issue
2020-03-26
Updated Outside Diameter, Required Dealer
*
Action
2020-03-25 Initial release

The seal lip material is affected to a high degree by the surface
finish over which the seal must slide. Mating surfaces that are
too rough can be abrasive and create leak paths. These include
burrs, tool marks or some other foreign matter on the surface
the seal lip contacts. Examine the surface the seal lip contacts
for any imperfections that could cut or wear the lip of the seal.

Purpose for Service Bulletin

Any vehicle with seals or gaskets.

If a fork seal leaks between the seal lip and the fork tube, nicks
caused by stones or dried insects are often the cause. Stones
can cause small nicks on the tube surface which will quickly
wear a seal or tear the lip. Dried insect carcasses are extremely
sharp and can also damage a seal. Clean them off as soon as
possible. If the issue is found to be stone nicks, the fork tube
must be replaced or the nick repaired using a fine sharpening
stone. Neither of these causes of seal failure are considered
warranty items.

Markets Affected

Outside Diameter

All markets are affected.

If the leak is found to be around the outside diameter of the
seal, remove the seal and inspect the bore that it is pressed
into. The surface finish of the bore can create a leak path and
is difficult to diagnose. Tool marks from the boring operation
could be present and not allow the surfaces to correctly seal.
If the seal is not properly seated or oil is leaking from around
the outside of the seal and there are no obvious surface defects,
it is possible there is a surface finish issue. It may not always
be a rough surface on the bore but a surface finish that is too
smooth. In this case, coat the outside of the seal with crankcase
sealant before installing the seal.

To inform dealers on how to diagnose leaking seals or gaskets.
This can sometimes be difficult, unless oil is obviously pouring
out of the seal. Usually, a seal will weep or leak at a very slow
rate.

Motorcycles Affected

Diagnosing the Source
Seals do not simply fail. If a seal is leaking on a new or relatively
new motorcycle, chances are good that another issue caused
the seal to fail. Premature seal failure is usually due to damage
to the seal lip or an issue with the bore the seal is installed in.
Over time, seals can also wear or deteriorate due to
environmental effects. Seal technology has improved throughout
the years with new and better materials and a better
understanding of surface finishes required for specific
applications.
Always examine the seals internal and external mating surfaces
carefully when making repairs.

NOTE
Avoid making unnecessary repairs. With an unnecessary repair,
there are risks of cosmetic damage, introducing debris,
re-introducing assembly lube and/or misassembly, which does
not justify the unnecessary service.

Common Types of Leaks
There are two basic types of seal leaks:

Some leaks are due to a gouge that was created in the surface
of the bore when the seal was removed. If the leak is due to
damage created during seal removal, the repair is more involved
than this document can cover. Gouges and other marks caused
during seal removal and installation usually require replacement
of a housing and are not covered under warranty.

Seals
See Figure 2. By design all seals leak at a very low, controlled
level. For example, dust will sometimes be seen at a seal
interface over time. Unless fluid is running or dripping, this is
acceptable. Otherwise the replaced seal is expected to perform
comparably.

NOTE
In the interest of preserving customer safety and satisfaction, always check for outstanding recalls whenever any motorcycle is brought into your dealership for either maintenance or service.
ROUTING

INITIAL HERE

SERVICE
MANAGER

SALES MANAGER PARTS MANAGER

WARRANTY
PROCESS
MANAGER

LEAD TECHNICIAN TECHNICIAN NO. 1 TECHNICIAN NO. 2 TECHNICIAN NO. 3 RETURN THIS TO

Only replace a seal if confirmed to be running or dripping fluid.

1439541

Residual Assembly Lubricant
See Figure 1, Figure 2 or Figure 3. Powertrain components
may be lubricated at assembly and in service. This is true of
O-rings and seals, as well as some fastener threads. This is
done for consistent, quality assembly. Though cleaned
post-assembly, residual lubricant can appear at joints and
valleys in the first operating cycles. Also, oil can drip and collect
in a groove or gland in service. This can likewise migrate out
later in operation, so understanding the source of the fluid is
important. Such observations should be wiped away.

Required Dealer Action
To efficiently diagnose an oil leak the technician needs to
confirm that the fluid is not residual from assembly or an earlier
service repair by following these steps:
1.

Using an aerosol cleaner, clean all the oil, dirt or other
debris around the suspected area.

2.

Add the fluorescent additive dye to the oil.
Special Tool:
(HD-28431-6A)
a.

FLUORESCENT

ADDITIVE

(OIL)
1439545

Use the HD-35457 I-Sheet.

3.

Warm engine up and take vehicle for normal test ride.

4.

Using a black light, check for fluorescent glow around the
suspected area.
Special Tool:
(HD-35457)

BLACK

LIGHT

Figure 1.

LEAK

DETECTOR

a.

Dye is visible: Repair should be made.

b.

Dye is not visible: No leak present, do not repair.

NOTE
Harley-Davidson recommends documenting these conditions
with photos.

Figure 2.

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M1513

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Figure 3.

M1513

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