Sorry I'm late
The HST fluid in all Honda snowblowers is good for the life of the unit
. The only regular service is to check the level and top off. Leaking units (rare) would need to be inspected and the source found. The HST fluid is not consumed like engine oil, nor does it ever really wear out. Unless you're having some kind of problem, leak, etc. there is no reason to just "change the HST fluid."
But, if you think the fluid is contaminated or other problems, there is a drain bolt, BUT, if you drain the fluid, then refill it, you must fully bleed the transmission, and to do this properly requires removing the transmission
from the snowblower. I've never known someone to do this while it is still installed, and based on the bleeding procedure, it does not seem viable. Strongly suggest you don't drain the transmission, but just check and top off the fluid if it is not leaking or having any problems.
Still reading? Okay, there is a drain bolt on the lower part of the transmission case near the transmission release lever. You may need to tip the unit rearward to fully drain the case. (sorry, I don't have a good clear image of this).
When refilling, the total capacity of the transmission is 0.793 quart, and it is very important to only fill with genuine Honda HST Fluid. No other aftermarket fluid/oil is approved for use with a Honda hydrostatic transmission. FYI, Honda is NOT trying to get rich off this, the engineers had to create a special formula for the Honda HST, and no other fluid was ever tested or approved. There is a scale on the side of the fill tank with UPPER and LOWER level marks, and fluid should be filled to meet the mark matching the outdoor temp.:
Next, you must bleed the system
to purge all air; here's the procedure.
1. Remember, this assumes you have removed the transmission from the unit. That procedure requires:
a. remove engine
b. remove auger housing
c. remove tension pulley / auger brake
d. remove tracks (TA models)
Genuine Honda factory shop manual (paper only, ebay or amazon, direct from Honda, free shipping and updates for 3 years)
Genuine Honda HST fluid, 1 quart bottle, Part Number 08208-HST01
. Google the part number to find online, or use this link to find a local Honda dealer:
Find A Honda Dealer