100,000 mile club

[lawrenze04]

At 143000 miles on 2012 Yaris Sedan. Dealership recommends me to replace the throttle body and flush the brake lines. What are your thoughts? Also they said that I have a timing cover leakage, which when I dont see any obvious leak. Anyone with the same experience?

[zoidberg444]

Originally Posted by lawrenze04

At 143000 miles on 2012 Yaris Sedan. Dealership recommends me to replace the throttle body and flush the brake lines. What are your thoughts? Also they said that I have a timing cover leakage, which when I dont see any obvious leak. Anyone with the same experience?

I've only heard of one instance of the throttle body going bad on a Yaris and if one did fail it would be better to get a used one from a scrapyard. No sense in paying for a new one.

I change my brake fluid and flush my lines every 2 years/40,000 miles. You definitely notice a change in the colour of the fluid as you flush the new stuff through. Brake fluid absorbs moisture so it can cause corrosion in your brake system.

I think they are having you on with "timing cover leakage" the timing covers are siliconed on at the factory. They are a bitch to get off and very unlikely to be leaking. You could have your front main seal leaking at the camshaft - that you should probably get fixed if it was the front main seal. Or you could have a coolant leak from the water pump. Mine leaks a little but i'm just keeping an eye on it at the moment because its just a drip. I just top up a few drops of coolant when i service the car.

[lorne]

Originally Posted by lawrenze04

At 143000 miles on 2012 Yaris Sedan. Dealership recommends me to replace the throttle body and flush the brake lines. What are your thoughts? Also they said that I have a timing cover leakage, which when I dont see any obvious leak. Anyone with the same experience?

CLEANING THROTTLE BODIES
In my humble experience, any crud on the throttle body can be cured with a spray bottle chemical. I've watched a licensed mechanic here in Japan pull the air-box conduit, and then spray the daylights out of the throttle body while reving the engine on the under-hood linkage. It cleared up the rough idle and stalling, and the vehicle was good to go until it went to automotive heaven! This is a pretty normal thing! There is a SPECIFIC chemical spray for this application!! I see this stuff in the wholesale, pro-tool and supplies shop I go to here in Japan.

FLUSHING BRAKE LINES
This should be a standard part of maintenance. In Japan, it's done every two years as common practice! DOT-3 brake fluid is hydroscopic.This means it absorbs moisture. The hydraulic system has to vent, and thus it is open to atmosphere. It eventually collects H2O in your fluid. Water will settle in your brake lines and in your hydraulic brake cylinders and callipers. I think you are really pushing your luck at 143,000 miles / 230,000 Kms!

Believe me — I've overhauled enough calliper bores, and either honed-out brake cylinders for new pistons and seals, or replaced them to know how they can rust and be ruined by contaminated brake fluid. You can work out the comparative cost of regularly flushing brake fluid as opposed to brake hydraulics overhauls. And I hate to think what might happen in the modern, pressure equalizer blocks — I never had to deal with those back in the days.

In Japan, the seasonal high humidity can be intense (not unlike many states in the USA). Here in Japan, as a matter of common policy, we flush brake fluid ever two years as part of the preparation for the mandatory licensing inspection. My wife and I ran a Honda for 23 years. We had one brake cylinder bore go bad in the 21st year. And not because of rust. The piston seal was weak. (Of course we replaced both cylinders.) The fluid had been flushed every two years, and the front callipers never needed service except for fresh pads.

If you are using DOT-4, it has a higher boiling point, but it is even MORE hydroscopic. So even more caution is advised. It must be great for track days, but I won't use it in my everyday transport.

And in case it has escaped you, water in the brake fluid detracts from stopping power.

TIMING COVER
As for the timing cover — I dunno, but if it means what I think it means, if there is no oil weeping around it, I cannot see the reason for servicing it with a new gasket or sealant. Perhaps the dealer knows that the gasket/seal does begin to weep or leak at about the milage your car has gone. Hell — leave it until it does leak and just keep an eye on it when you do your regular check on the dipstick.

(FWIW: I'm not a licensed mechanic, but years ago I serviced, repaired and overhauled stuff on motorcycles, cars and trucks for part of my living.)