This post will explain the actuator fluid change process on Suzuki Alto 660cc HA36S and which fluid you can use as a replacement.
If you don't like reading, you can watch the video here
According to Suzuki, AGS actuator fluid is a lifetime fluid hence you won't find any change interval in owner's manual. Also, dealerships usually don't have any clue when asked for it.
In my opinion, no fluid is a lifetime fluid. You will see later that actuator fluid color became slightly dark and gritty since I changed it at 3 years mark because I use my vehicle in severe condition i.e. a lot of short trips. After 5 years, the fluid becomes really dark.
A common recommendation I have seen on Japanese websites is to change the actuator fluid after 5 years or 50,000 km which ever comes first.
The part No. for the hydraulic actuator fluid is Suzuki 99000M24121-135 which I was not able to find at any Suzuki dealership. Also, its aftermarket alternate was hard to find.
After lengthy search, I was able to find "AHF 22 S" by a company Addinol. It could be used where Suzuki 99000M24121-135 is recommended and many others.
https://addinol.de/products/product-finder/addinol-ahf-22-s/?lang=en
You can buy this product from Addinol's official daraz store
https://www.daraz.pk/products/ahf-22-s-i347641409-s1775519696.html
Important
Do not open the driver side door before attempting this job. The reason for this
is as soon as the driver side door opens, the AGS actuator suck the fluid and the
level drops to "Min" in the reservoir. We don't want that to happen because we
would like to change as much fluid as possible.
Since you don't want to open the driver side door, you can pull the hood/bonnet
release lever from the passenger side. Or you can open the hood a couple of hours
before starting this job.
Remove the negative battery terminal in order to prevent actuator activation if someone accidentally opens the driver side door.
Open the reservoir cap
Once you open the reservoir cap, you will see a black plastic part for protection. Let's call it black plastic protector.
You can remove this protector using pliers. Using long nose pliers will make the removal easier, but normal ones can also work. Make sure you clean the tip of the pliers thoroughly before using it to remove the protector. I cleaned it using APC diluted 1:10.
I used a 60cc syringe and tube cut from a drip set to suck the fluid from the actuator reservoir.
This is the condition of lifetime fluid just after 3 years. It could be stretched up to 5 years but not more than that.
After multiple suction attempts, total 400ml was extracted
Then I measured the exact amount of fresh fluid in the same jar. But before pouring fresh fluid, I washed it thoroughly and dried completely using a hair dryer.
Then pour the fresh fluid in the reservoir. The new fluid is in dark green color. It looks like Addinol dyed it to match with its branding.
Put the black plastic protector back and close the reservoir cap. Re-connect the negative battery terminal and that's it.
It's been a couple of weeks since I changed the fluid. The transmission is shifting perfectly with no issues Alhamdulillah.