Brake actuator general questions

My recently bought 2009 Base model with 146k is making the classic symptoms of the failing actuator. Making noise every few seconds. The car came with a used unit in the trunk with part number 44510-47050. Seems the previous owner was planning to replace it. It does not look good and have rust in some areas. My questions are

1. Part number listed on Toyota website is 44500-47141. But the website photos shows 44510-47051. Read that this is the actual part number. ?
2. 44510-47051 - does it have failures like the 44510-47050 version? Or it will also fail within couple of years? 44510-47051 - i can get one <$600 in ebay. Seems to be good units. If this one also have failures, i would prefer to go with new one.
3. Online/ebay router - they sell without the resistor - Can i re-use the existing or will it create problems?
4. Lastly, does the failing actuator affects mpg? It stops the regen braking? I am getting 33 now.

Please see below. Brakes works fine so far and no codes. It is highly irritating.
2009 Prius Brake Actuator Sound - YouTube

Thanks,

 

Did you used 44510-47051 or 44510-47050 ? I live in Dallas, TX. Local junk yards, didn't find many with good units. Online i found one with $415 for 44510-47051.

Used units, what i read is, 44510-47051 is revised unit. But cant find any concrete information on it fixed the issues from 44510-47050. The used unit i found in the car is the older model and that's why i was reluctant to try it. I guess it is worth a try first.

 

The above is the photo of the actuator i got from the trunk of the car

 

Wonder what kills it. Design.Manufacturing defect or not changing the fluid on time.

Found 2 on ebay with 44510-47051 (updated part number) . <$500. For some reason it is not allowing me to post links. item numbers 276537391229 and 266859822180.

 

Bought the new one from local dealer. $1280 (including tax and all). Also bought the Autel MaxAP 200 and software have feature for air bleeding. Going to replace it as soon as possible. It showed the ABS light once time and got cleared accidentally by me when testing the Autel scanner. Also bought 10 mm Flare nut wrench.

Watched several videos. Planning to replace the resistor also which seems like buried inside. Here is my plan.
1. Remove 12V battery cables and disconnect HV battery
2. Drain coolant and remove inverter (saw some video without removing the coolant hoses, but seems less convenient)
3. Using a vacuum (mighty vac), take out as much as fluid from brake fluid reservoir. Might use a syringe also.
4. Remove the cabin heat auxiliary water pump from it's mount. But all hoses connected
5. Disconnect the big hose to the abs unit, collect the fluid in a plastic container.
6. Remove hydraulic lines, cable connector and 3 nuts holding the unit with bracket
7. Take out the unit, swap with the new one
8. Attach it back and connect only the fluid in line (big one)
9. Fill brake fluid slowly and as soon as it starts filling up and draining from the ports, connect each brake line and the top one on the last
10. Put all 4 sides on jack stands and remove wheels
11. Over fill the reservoir and pump pedal and bleed from 4 wheels until no air left. Might have to do like 20 times pumping and removing the bleeded.
11. Reinstall the Inverter, fill coolant.
12. Replace the resistor
13. Remove abs pump relays.
14. Connect the 12V and HV battery and a charger to the 12V
15. Power on, (not engine). It will beep crazy because of the missing relays
16. Connect the autel reader and follow the bleeding procedure with "actuator removed" option. Bleed / fill fluid as needed.
17. Now do abs bleeding as insructed
18. Power off , put relays on
19. Continue on reader.

NOTE:: might have to bleed more than once to remove all air from system.