100K maintenance fun

[hobbit]

I have accumulated enough pictures and notes from various little
maintenance and checkups I've done over the course of this year
that I figured it needed to be written up in a new set of pages.
It's not the comprehensive be-all authoritative reference on
what should be done at 100,000 miles, but covers a few items
that people have been curious about or have been incompletely
documented in the past.
.
This rambly six-and-a-half part rundown so far includes

• Tires and alignment
• Brakes and the benefits of regen
• Brake fluid studies
• MAF sensor and intake/throttle
• Spark plug lifetime illustrated
• Serpentine belt and water pump
• Easy headlight removal and lamp discussion
• Inverter temp monitoring
• Inverter pump swap
• Coolant testing/study
• Transaxles and SSC-50P

along with lots of fun references, pix of some very obscure Prius
parts nobody's ever seen before and never will again, and a couple of
items deferred until later on.
.
The inverter-pump part is probably the most useful, as many of our
second-gens start nearing the six-digit mark.
.
_H*

[paprius4030]

Hey Hobbit, thanks for the interesting and entertaining read. I got a question for you. Since it seems such a PIA to monitor the inverter temp., is there an easier way to just rig up an idiot light to let you know if the inverter pump fails while your driving?

[Matt Herring]

Great info. Hobbit! Good reference materials for any maintenance/repairs in the future (hopefully the not so near future). Thanks!

[jayman]

Hobbit

As usual a good writeup

Brake fluid in the Prius does appear to stay in good shape far longer than in conventional vehicles. I'm not really sure why.

I do know that with most conventional vehicles with translucent fluid reservoirs, after 2-3 years the fluid will turn from a light honey color to a very dark color. Some even turn black

I did a brake fluid flush on my FJ this summer, as I noticed the fluid was starting to become dark. This is after only 2 years and 25,000 km! For some reason, the rear disk brake calipers had a lot of fine suspended trash in the fluid

Like the Prius, the FJ has electric assist brakes. I carefully instructed the helper to only keep light pedal pressure, ign on, while bleeding the rear brakes. Like the Prius, the pedal does NOT sink when bleeding the rear brakes

The front brakes feel more "normal." After I was done, the pedal felt a lot firmer, with a bit better response. The right rear caliper did burp a bit of air before fluid came out the tube

[Grateful11]

Awesome info site there Hobbit! Thanks for taking the time to provide for us.

[efusco]

Great stuff Hobbit....coming through MO anytime in the next 5 months, I'd trust you for my 100k services before the local dealer....but I'm not comfortable enough around the car do to all that stuff myself.

[tochatihu]

Jayman, do you think that Prius brake fluid experiences smaller temperature extremes than in 'friction-only' vehicles? This would probably limit the chemical interaction rate between fliud and brake system components, but I don't see how it could reduce water absorption as such.

Will Hobbit's garage schedule appointments for Prius work?

[galaxee]

ahh, finally! DH has been arguing for years that brake fluid doesn't need to be flushed all the damn time in these cars.

[hobbit]

I wish the bloody inverter loop had an actual *flow* sensor on
it. I think Bob or somebody was talking about adding one at
one of the hose connections, but finding the right sensor and
plumbing it in wasn't going to be easy..
.
_H*

[Patrick Wong]

Hi Hobbit,

I especially enjoyed learning about headlight removal without first removing the entire front bumper cover, and your experience testing the used brake fluid. Thanks for sharing that very useful knowledge with forum members.

It was also interesting to read about your use of the black plastic fasteners (that are used to secure the plastic fender liners) in other areas of the car. I also came to that realization yesterday when I had to replace the two plastic clips that hold the two black plastic cowl pieces. The fender liner fasteners work well in that application and are easy to remove.

I wanted to comment on the engine water pump seepage that you've noticed and your policy to keep the serpentine belt relatively loose. I realize you live in the Northeast and are a hypermiler, thus I assume that your engine doesn't see 5,000 rpm often while ambient temps reach 90+ degrees F at highest. That may be why your loose serpentine belt works OK.

The manufacturer's spec on the serpentine belt tension has to take into account all reasonable use scenarios. My car routinely sees 75+ mph speeds (as that is the speed limit on Western rural highways) and ambient temps can get up to 120+ degrees F. I definitely do not want the belt to slip when the engine is revving up under those conditions.

MSRP for the pump is $92 and I can buy it for $70 plus shipping.
http://www.trademotion.com/partlocator/index.cfm?action=getLocator&siteid=213747&chapter= APM820&appSectionid=8&groupid=62105&make=34&model= Prius&year=2004&catalogid=1

Since this pump is so inexpensive and is relatively easy to replace, what is the motivation to eke out the last bits of service life?

In my case, as soon as I see the slightest hint of pink coolant weeping out, I will place an order and replace the pump the next weekend. I don't want to have an unscheduled failure literally in the middle of nowhere...

I recognize that reasonable people can have different opinions on this, depending upon their particular situation and circumstances, and tolerance for an unscheduled failure. This is like some owners who wait until their 12V battery fails before installing a replacement, while others (like me) will install a replacement based upon years in service.