Table of Contents
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REF: Oiling & Lubrication
Transmission \ Primary Oil
About JASO Certifications
- JASO introduced the MA and MB oil specification to distinguish between friction modified and non friction modified engine oils. Most four-stroke motorcycles with wet clutches need a JASO MA oil. 1)
- The JASO MA - MB range:
| JASO MA | JASO MB | |
|---|---|---|
| Dynamic Friction Characteristic Index (DFI) | ≥1.45 and <2.5 | ≥0.5 and <1.45 |
| Static Friction Characteristic Index (SFI) | ≥1.15 and <2.5 | |
| Stop Time Index (STI) | ≥1.55 and <2.5 | ≥0.5 and <1.55 |
- The JASO MA range is further divided into 2 distinct ranges - JASO MA1 and JASO MA2:
| JASO MA1 | JASO MA2 | |
|---|---|---|
| Dynamic Friction Characteristic Index (DFI) | ≥1.45 and <1.8 | ≥1.8 and <2.5 |
| Static Friction Characteristic Index (SFI) | ≥1.15 and <1.7 | ≥1.7 and <2.5 |
| Stop Time Index (STI) | ≥1.55 and <1.9 | ≥1.9 and <2.5 |
Transmission Oil Capacities
| 1957-1990 2) 3) 4) 5) | 1.5 pints (24 oz) (710 ml) |
| 1991-1992 6) | 40 ounces (1183 ml) |
| 1993-1996, 1998, 2004 7)8) 9) 10) | 32 oz (946 ml) |
When to Check/ Change Transmission Fluid
| HD Transmission Oil Recommendations | Check Change Only If Needed | Change |
|---|---|---|
| 1959-1978 13) 14) | Every 1,000 miles | Every 5,000 miles or 1 year, Every Spring or Fall |
| 1979-1985 15) | After first 500 miles, Every 5,000 miles, Spring or Fall |
|
| 1986-2003 16) 17)18) | After first 3,000 miles, Every 2,500 miles after oil changes | After first 500 miles Every 5,000 miles after |
| 2004 19) | After first 1,000 miles, At first 5,000, Every 5,000 miles after |
Brake System
- Brake caliper mounting bolt O-rings- Dow Corning 44 grease (“Pin Lube” in parts kit) 20)
- O.D. of brake caliper piston (including chamfer), caliper piston bore and I.D. of the installed piston seal - Novaguard silicon grease.
- I.D. of upper caliper (threaded) bushing bore, O.D. of threaded bushing, I.D. of upper and lower caliper mounting pin bores - Dow Corning 44 grease (“Pin Lube” in parts kit) 21)
Brake Fluid
HD Recommendations
When to Check or Change Brake Fluid
| Year Model | Check | Change |
|---|---|---|
| 1959-1969 | ||
| 1970-197826) | Every 2,000 miles | Every 5,000 miles |
| 1979-198527) | Initial 500, then every 2,500 miles | Every 2 years |
| 1986-199028) | Check at initial 500 then every 5,000 miles, prior to storage or annually | Change/ Replace as needed |
| 1991 to 200329) | Every 300 til and including initial 1,000 miles, then every 5,000 miles | Replace as needed |
What Type Brake Fluid Do You Have
When in doubt,
- 1st check your bikes service manual to see what should go in it.
- Next, get a few drops of brake fluid from your brake reservoir and put them in a small container. Add a few drops of water and mix it all together.
- If the water mixes with the brake fluid, it is DOT 3, 4 or (5.1).
- If the water does not mix with the brake fluid it is DOT 5. 30)
The Color Check
- DOT 3 is available in Clear, Pale Yellow, Blue & Crimson Red.
- DOT 4 is available in Clear, Pale Yellow & Crimson Red.
- DOT 5.1 is available Clear, Pale Yellow & Blue.
- DOT 5 is available in Purple & Violet. 31)
The presence or absence of color is not a safe criteria to distinguish between the different types of brake fluids. The color is added in brake fluid to detect leaks and color does not effect the quality of brake fluid. Since blue and purple sometimes can seem the same color depending on lighting, you could be mixing Dot 5 and DOT (5.1).
Mixing Brake Fluids
- Mixing different colors of the same type typically won't hurt the system as long as what you are adding to has not been compromised previously if your just topping off your existing fluid.
- You can typically mix DOT 3,4 and 5.1 fluids without damaging your braking system or compromising your existing braking performance. But as nearly every brake fluid manufacturer will state: doing so is not recommended. Why? Mixing good new fluid and old bad fluid means you will retain the bad fluid's performance and change the temperature ratings of your residual fluid. You can't mix any others with Dot 5 fluids. Mixing the others into Dot 5 would cause a meltdown of the rubber parts and/ or a break down of the silicone and possibly clog up the brake lines causing brake failure. Dot 5 into the others may release clogs into the brake lines also leading to brake failure.
- If silicone is introduced into an older brake system, the silicone will latch onto the sludge generated by gradual component deterioration and create a gelatin like goop which will attract more crud and eventually plug up metering orifices or cause pistons to stick. If you have already changed to DOT 5, don't compound the problem and change back. You will never get all of the silicone out of your system. Just change the fluid regularly. For those who race using silicone fluid, crack the bleed screws before each racing session to insure that there is no water in the calipers. 32)
DOT 3, DOT 4, DOT 5.1
- DOT 3 brake fluids are mixtures of glycols and glycol ethers. DOT 4 contains borate esters in addition to what is in DOT 3. These brake fluids are somewhat similar to automotive anti-freeze (ethylene glycol) and are not a petroleum fluid. Both DOT 3-4 and DOT 5 fluids are compatible with most brake system materials except in the case of some silicone rubber external components such as caliper piston boots 33)
- The problem with DOT 3-4 fluids is water absorption. DOT 3-4 glycol based fluids, just like ethylene glycol antifreezes, are readily miscible with water. Long term brake system water content tends to reach a maximum of about 3%, which is readily handled by the corrosion inhibitors in the brake fluid formulation. Since the inhibitors are gradually depleted as they do their job, glycol brake fluid, just like anti-freeze, needs to be changed periodically. 34)
- Fluid boiling point DOT 4 glycol based fluid has a higher boiling point (446F) than DOT 3 (401F), and both fluids will exhibit a reduced boiling point as water content increases.35)
- DOT 5.1 is also glycol-based and it's major difference to Dot 3 and 4 is it's dry boiling point (minimum 518F).
DOT 5
- Dot 5 is of silicone chemistry and not being water miscible, it must rely on the silicone (with some corrosion inhibitors) as a barrier film to control corrosion. Water is not absorbed by silicone as in the case of DOT 3-4-5.1 fluids, and will remain as a separate globule sinking to the lowest point in the brake system, since it is more dense. 36)
- Dot 5 in its pure state offers a higher boiling point (500F) however if water got into the system, and a big globule found its way into a caliper, the water would start to boil at 212F causing a vapor lock condition (possible brake failure). DOT 3 fluid with 3% water content would still exhibit a boiling point of 300F. Silicone fluids also exhibit a 3 times greater propensity to dissolve air and other gasses which can lead to a “spongy pedal” and reduced braking at high altitudes. 37)
Brake Fluid Boiling Points
- Dry Boiling Point: This is the temperature that your brake fluid will boil when its straight out of the sealed bottle. When there has been effectively no time for it to absorb any moisture. If you are racing on a track, you are most concerned with this value, since the fluid in your lines is likely to be freshly added. 38)
- Wet Boiling Point: This is the temperature that your brake fluid will boil when its been inside your braking system for a reasonably long time. How long it takes to get to this saturation point will vary by fluid type, but a good rule of thumb is the higher the dry boiling point, the faster the fluid will saturate (an informal sort of standard is…not always - used by fluid manufacturers: the wet boiling point is the reading taken after fluid has been sitting for one year in your brake lines). If you are riding mainly on the street the wet boiling point is going to be the one you want to pay attention to since the fluid will typically stay in your brake lines for an extended period of time. 39)
SAE Testing Brake Fluid Lubricity
- SAE is currently working on modernizing testing and standards for automotive brake fluids. Below are the standards that relate to brake fluid and their corresponding standard number.
- J1703- Motor Vehicle Brake Fluid Jul 20, 2015
- J1704- Motor Vehicle Brake Fluid Based Upon Glycols, Glycol Ethers and the Corresponding Borates Jul 20, 2015
- J1705- Low Water Tolerant Brake Fluids Apr 21, 2014
- J1707- Service Maintenance of SAE J1703 and J1704 Brake Fluids in Motor Vehicle Brake Systems
Link to Brake Fluid Comparison Charts on the Webb
- Interesting amateur test on mixing brake fluids http://www.buckeyetriumphs.org/technical/Brakes/Fluid/Fluid.htm
2)
1959-1969 HD Sportster FSM pg 1A-3
3)
1970-1978 HD Sportster FSM pg 1-1
4)
1979-1985 HD Sportster FSM pg 2-1
5)
1986-1990 HD Sportster FSM pg 2-1
7)
1993-1994 HD Sportster FSM pg 2-1
8)
1995-1996 HD Sportster FSM pg 2-1
9)
1998 HD Sportster FSM pg 2-1
10)
2004 HD Sportster FSM pg 2-1
11)
1991 HD Sportster FSM pg 2-1
13)
1959-1969 HD Sportster FSM pg 1B-6
14)
1970-1978 HD Sportster FSM pg 1-5
15)
1979-1985 HD Sportster FSM pg 1-2
16)
1986-1990 HD Sportster FSM pg 1-2
17)
1991-1992 HD Sportster FSM pg 1-2
18)
1993-1994 HD Sportster FSM pg 1-2
19)
2004 HD Sportster FSM pg 1-7
29)
1986-2003 Clymer Sportster Repair Manual
40)
article by Matt Robertson
41)
Seine Systems
42)
article by Marc Randolph
