2005 Prius - New Brake Actuator vs Entire New ABS System?

"ENTIRE ABS system" isn't really a thing. If he really meant that, he'd be talking about the actuator, the ECU under the dash, and a pile of other parts and brake lines.

He's surely just talking about the actuator assembly. The Gen 2 actuator assembly also includes the accumulator and pump, which were a separate assembly in Gen 1, and again in Gen 3. So, in that respect, the Gen 2 actuator assembly is "one piece" compared to those.

So for your Gen 2, there's not really much of a question here. You and your mechanic are both talking about a replacement of the Gen 2 brake actuator assembly, and the only real question is whether the price can be improved on.

 

The resistor is tucked up under the top of the dash in a place not easy to reach. If a shop were going to remove the upper dash for easier access, I could imagine that sort of a labor charge for it.

Although a new actuator comes with a new resistor, not everybody bothers to change the resistor. I even remember seeing at least one thread where somebody wanted to change it and managed to do it from below without removing the dash top.

 

if you're near tampa, give tampa hybrids a call. not sure if they work on gen 2.
if not, call a few dealers. i think around $2,500. is the going rate

 

I've done several of these brake actuator jobs, including swapping the resistor. The resistor can be changed in 20 minutes just by removing the left dash vent so you can see better while reaching up inside. Resistor is mounted on the left side wall using one 10mm headed fastener. A bit awkward, but not difficult or time consuming. EVERY resistor I've seen has been identical, part # 44535-47050 193.6 milli-ohms. I replace them when installing a new actuator, just because it comes with it, and if I were a customer who just paid $1200 for a new actuator from Toyota, I would want ALL the new parts installed. Does the resistor HAVE to be swapped?..no.

And the actuator can be purchased online for <1200 bucks all day long.....

 

well, you can't really argue with 18 years

 

Regarding the resistor - isn't it possible to test it by putting a multimeter on a wire and ground (or two wires) somewhere? My experience with bad resistors is that they either are in spec and are not physically damaged, and you leave them, or they are bad in one or both of those ways and you change them.

 

Hard to practically test a 193.6 milli-ohm resistor without a milliohmmeter, a specialized instrument not everyone'll have lying around. Here's one that Toyota recommends for jobs that need that kind of test.



(Notice the double-wire, source+sense test leads with Kelvin clamps, to eliminate the test lead resistance error that you normally don't worry about when measuring bigger resistances.)

 

The problem with Prius brake actuators is no one has figured out how to rebuild them - so there are no aftermarket options other than straight out used.

Even used is a crap shoot since the labor is the same and you could end up with another bad part or a used part that quickly fails.

Considering a complete failure of your actuator may suddenly increase braking distance and eliminate stability control leading to an accident, new is the way to go.

Concerning the resistor, I would arrange for it to be left out unless it is clearly needed after the new actuator is installed. Save the part and its labor cost for now and most likely forever.

 

Well yeah, sure, but do these ABS resistors really fail by going from .2 Ohms to .3 Ohms, which would require a tool like that, or do they fail by going open, or at least to several Ohms? Blower motor resistors, which also have a very low resistance, tend to test open, or be pretty obviously burned up. I guess some resistors could short across parts of a wire coil and end up with a lower resistance than specified, but I cannot recall ever reading of a car where one of the fan speeds was going quicker than it should have due to that sort of failure.

 

I don't know; I'm not sure I've ever seen a report of one failing at all. I'm not completely sure why Toyota always supplies one along with a new actuator. The idea that they are carefully matched to each pump motor doesn't seem to hold up with TMR-JWAP seeing the same 193.6 mΩ value for every one.

If the resistor were to fail open (or some extra high resistance), there'd be no low-speed pumping, so if you had that symptom, it might be worth checking.

 

My quote was about the same here in NOVA. I was skeptical about the resistor charge but apparently they need to pop the panels in the front to get to it; not sure you can really get to it from the bottom, as others claim.
The OEM actuator with resistor was about $1300 (tax included); the replacement cost for the labor was $1515, including a new inverter pump and rear (drum) brakes. Was it worth for nearly 3K the total cost? It was either that or the hassle to buy a used car for a lot more and possibly deal with more car issues; after the repair, that long beep, knocking, and vibrating noise coming from the actuator went away and my Prius is smoother and even getting better mileage. I wouldn't be so comfortable had I put a used actuator instead and not having replaced the resistor. @ 208K miles, I'm hoping this Prius will give me another 50K-100k miles.

 

I would guess that the others who report having done it might be on to something.

 

I've done this a handful of times. The resistor has always been stamped with identical values and is replaceable by reaching up from the bottom. It's mounted by one 10mm hex head bolt on the driver left sidewall. Remove the left dash vent to help with the view. Easy squeezy....