Transmission And Brake Fluid Question

[Bigla]

I have an 09 RX350 with 93,000 miles. Have never had a problem with it and aside from oil changes, changing air and cabin filters,and keeping an eye out for things, have not had any extensive maintenance performed. The manual says that transmission oil and brake fluid should be changed.

Local mechanic told me that and oil drain and replace rather than a transmission flush would be sufficient unless i was having problems or car had 150k with no change of oil. Any opinions?

Brakes are great, only replaced front and rear once. Is changing brake fluid important?

Anything else I should do at 93,000 miles.

Thanks,

Larry

[RX400h]

What does your owner's maintenance manual list for transmission fluid change intervals? If 90,000 miles is listed, then a simple drain and fill is all you need. Regarding brake fluid changes: The mechanic should have testing strips that detect the amount of copper in the fluid. Brake lines are lined with copper, which will leach into the fluid if excessive moisture is present. Have the fluid checked to determine if a flush is necessary, but at a minimum, fluid should be flushed when pads are replaced. Hybrid pads typically last more than twice as long as non-hybrid pads, so it looks like you are easy on your brakes.

[Bigla]

Thanks for the info. Didn't know about the copper in fluid and will have that checked out.

Larry

[Rawhide]

Transmission fluid deteriorates exponentially with heat. Fortunately the RX-350 has a transmission fluid cooler which keeps the temperature down. Unless you tow up hills, you probably never have to change it.

Brake fluid absorbs moisture. It's a function of time, not mileage. If you don't change it, you run the risk of expensive brake maintenance due to rust of calipers, etc. I have it replaced every 3 years for preventive maintenance.

[Bigla]

Thanks for info Rawhide.

[lenore]

Personally I would have the transmission fluid drained and filled. DO NOT do a flush. There is no such thing as lifetime, that is a sales pitch. I guarantee you the fluid is reaching end of life.

[Rawhide]

Lenore, that is interesting. What is your guarantee based on? I've had a Chrysler van and Honda van, both of which had the transmission fluid changed per mfg's rec and both had transmission failure anyway at about 70k miles. My daughter has a Toyota van that never had the transmission fluid changed, and it has over 250k miles without a problem. High heat will cause the fluid to deteriorate in a remarkably short period of time, perhaps a few thousand miles. So if the transmission gets hot, it can fail even if the fluid was recently replaced. My Lexus has a transmission cooler, I've followed the mfg recs, and not had a problem at 70k yet. My new Honda van also has a transmission fluid cooler. Do you know of any vehicle (especially a Toyota product) with a transmission cooler installed that has had a transmission failure when the mfg recs were followed?

[lenore]

• Yep, my former RX300 had the transmission fail at exactly 101k miles, the fluid had been changed prior. I have heard of many Honda's etc having transmission failures. My thoughts on the fluid change is that it is cheap insurance to provide fresh fluid with no breakdown. Yes these cars have coolers, but that doesn't mean that gears, bands, plates etc aren't going to contaminate the fluid. I changed the fluid on My Present RX400h at 80k miles and the fluid was brown. That is not a good color for any transmission fluid. Lifetime, and I mean this is strictly a sales gimmick to make consumers feel there is no additional cost of maintenance. I am on five car forums and I can guarantee the consensus is change the fluid. Note: I have been tracking transmission failures for years on the Lexus RX300 and I have emails from no less than 100 people with this problem. All said the same thing, (I thought Lexus/Toyota products were a reliable product) All cars have failures, but preventative is the best medicine.

[Rawhide]

Your comments make perfect sense. As you say, all cars have failures, and some models have way more than others despite the manufacturer's reputation. My experience with transmission fluid changes has not been good. It's common sense that clean(er) fluid is better, and it's cheap preventive maintenance. It just hasn't made any difference in my case. Depending on the model, when it's time for them to fail, they fail.

True story. Years ago I took my station wagon to a local garage for a transmission fluid change. When it was done, the manager called me up and said "I have good news and bad news. The good news is the transmission fluid is changed. The bad news is your car is totaled!" I said "WHAT?" A woman was driving past the garage on the way to pick up her welfare check. Just then her engine died so she lost power brakes and power steering. The garage is on a bend, so she went straight into the garage parking lot and plowed into my car, totaling it. Worse, my car plowed into the car beside it.

[Bigla]

Thanks everyone for you input.

Larry

[RX400h]

My 1989 Mazda MX6 GT auto tranny has almost 160,000 miles on it and is still shifting, perfectly. Over the 17 years that I have owned it, I have changed its fluid every 2 years. Most likely, I did not have to change it so often, but it was so easy to do when the car was up on ramps for its oil change. Really, it's the design AND maintenance that matter.

[Jonathantphan@yahoo.com]

I change the transmission fluid after 90 ,000 miles and 24,000 miles afterwards

[dcfish]

For 15 years I have done a tranny drop and fill (2 quarts Toyota T4) Everytime I change the oil. Less than $20.00 a year is cheap insurance for a Transmission ;) I also have an inline Cooler and Filter for the Trans that I installed. The Fluid always looks new.