Bought 2012 RX 350 7 months ago from certfied dealer with 74,000 miles. Pre purchase inspection by my mechanic showed dirty transmission fluid and moisture in brake lines. Certified dealer had transmission serviced at Lexus dealership. Certified dealer changed brake fluid. At 76,000 + miles just had mechanic do the 80,000 service; he noted, again, that tranny fluid dirty and 4% moisture in brake line. Contacted Lexus dealer re why transmission fluid was dirty again at only 2,250 miles since they last serviced tranny. Manager told me that the tranny fluid is a "lifetime" fluid and doesn't have to be changed, and only tranny fluid added is necessary if tranny fluid level low. Lexus dealer manager also told me that brake f,plaid only needs to be changed after next 30,000 miles. My mechanic says that for tranny and brake systems and parts to work as they should, that tranny fluid should be changed, and brake lines flushed to remove moisture from brake lines. Who is correct? I have extended warranty on vehicle and want to make sure that manufacture recommended service is completed, and to protect my investment. Thank you.

 

My local Lexus service manager told me do not change your transmission fluid that it could cause more harm than good. I find it ironic the posters that complain about Lexus over charging on items that are not needed and than insist their transmission fluid needs to be changed.

 

I am a bit confused by your post as you initially state the transmission was serviced, then call that into doubt, same with brake fluid. Do you not have any service receipts?

Per Toyota the brake fluid should be changed every 3 years as it absorbs moisture. Get the fluid changed, it should cost no more than $130.
If you plan to keep the vehicle, get the transmission flushed. It will extend its life, shift quality and maybe mileage. It is not cheap to do a flush or as the correct term is, a "fluid exchange" on these vehicles due to the complicated Toyota/Lexus requirement for adjusting the fluid level that is dependent on fluid temperature. Plan on $200 - $300 for a transmission fluid exchange.
The warning not to ever change the fluid is old school thinking from when people did not every change it until over 100,000 miles and were afraid of stirring up contaminants. The claim that it is lifetime means it will last until the warranty is over and that that dealer does not have the equipment or skills to do a transmission fluid exchange.
Your vehicle is overdue for such a service if it was not done. FYI, even new fluid will look dirty in a couple of thousand miles. That is not a way to determine if it was done or not, you would need a fluid analysis.

Do some searching on this forum using the words transmission flush as there have been several other threads on this subject.

 

Thank you both for your comments. I hope this clarifies my question: Before I bought the RX 350 from the certified dealer I had my mechanic do an inspection. One of his recommendations was to change the tranny and other fluids because they were dirty. Vehicle had almost 74,000 miles. Certified dealer agreed and sent it to Lexus dealer to replace tranny fluid. Yesterday, about 2,200 miles later, car was in for 80,000 service at my mechanic. He noted, again, that tranny fluid was dirty. Today, I was able to obtain invoice from Lexus dealer who did work 7 months ago. Invoice confirms that tranny fluid was not "exchanged". They only replaced 2 of the 7 quarts. My mechanic saw the invoice and confirmed what Clutchless said; "he hit it right on the head". My mechanic also said that the machine they use to replace the fluid does not put damaging pressure on the tranny and will not harm the tranny system if done correctly, Needless to say, I plan to keep the car for a long time, and want to make sure the tranny system has a satisfactory quality of fluid as it reaches 100,000 miles, and at other necessary intervals as well. Clutchless was also correct on the cost of the tranny "fluid exchange"; I plan to pay about $200. Well worth the cost, and investment in the tranny. Thanks again.

 

What do you mean by Certified dealer?

 

Carmax is the dealer I bought the 2012 RX 350 from about 7 months ago