I had a 1992 LS 400,it was a great car,drove it to 210,000 miles. At around 200K started having power steering problems. Ended up replacing the pump, rack and lines. I never changed the power steering fluid. Is this something we should do as LS 430 owners to possibly prolong the life of power steering components? How about changing brake fluid?

 

change power steering fluid and brake fluid every 30k or 5 years,
you should be all set, tranny fluid every 30 as well, and use mobil 1 extended performance 5w 30 oil and your car will last long time. change rear differential fluid every 9 years or 60000 miles

 

Thanks for that valuable information. Just bought it with 112,000 miles,I probably should change all the fluids, don't know if it's ever been done. I've never used synthetic oil in any of my cars, is it worth the expense and how often do you change it? I love this forum, we are all so passionate about our cars.

 

I've used only synthetic oil in my cars since 1991. The gas turbine industry pioneered synthetic oil and found it greatly reduced engine wear. They proved this by taking frequent oil samples and analyzing for metal particles. Mobil 1 was that oil. I changed the oil in my 92 SC400 every 3750 miles (the recommend mileage back then) even though I was using Mobil 1. The guys I worked with (Aerospace engineers) wanted to know if they could get the oil I drained at 3750 miles!

I wouldn't think of using anything else. I'm still a bit conservative and change the synthetic oil every 5,000 miles in my LS430.

 

with the car having the mileage, look for a high mileage synthetic, the mobil 1 extended performance is at walmart for 29 for 5 gallson cant be beat, as far as the fluids if you have 112 k change the fluids to provide peace of mind, with age the fluids become contaminated, much cheaper than replacing a power steering rack or a master cylinder because of fluids
safe driving

 

One of the biggest "wallet flushes" in the industry is power steering flushes. It's basically a mandatory upsell every shop now tries on customers.

It's a good idea to change the power steering fluid, but I think it's a misconception that it needs to be frequently done, or that your power steering pump with 200,000 miles died because the power steering fluid wasn't changed enough. Power steering fluid is hydraulic fluid within a closed system, much different than how an engine works. How often do you change the oil in your AC system?

My opinion is that power steering fluid should be changed about as often as you change your timing belt, and even that is probably over doing it. I don't even think the owner's manual states to ever change the power steering fluid at a certain mileage interval.

 

Having fluid analysis for TBN or TAN is helpful as the lubricity properties will begin to change over time with heat cycling. Some assemblies will do better and others not so under varying operating conditions. Following the manufacturer intervals for fluid changes is safe and conservative.

For the LS400, we've seen enough samples when the fluids are not changed per the factory intervals. The 430's are now coming into the higher mile ranges so we'll see what longevity results are under the owner's maintenance schedules. Oxidation also is part of open system fluids over time.

 

I have the brake fluid flushed every 2-3 years depending on how it looks. It turns darker as it oxidizes and ages. Keep it clean and light clear looking by changing the brake fluid every 2-3 years.

PS fluid is very simple to keep fresh. Just get a hand pump and pump out the PS reservoir and refill with new Dexron II fluid 2-3 times a year. Takes 5 minutes to diy drain and refill the tank. Repeat over a couple of days 2-3 times once a year and your PS fluid will stay relatively fresh and clean. Hand pump sold at any auto parts store for $5. and a quart of Dexron II AT fluid is about $5 also. So for $10 year and 15-20 minutes total diy work, you almost guarantee never having to replace your PS pump.

Also its a good idea to drain and fill rear differential periodically. Changing diff fluid like changing PS fluid is one of those things that was never done back in the old days when most cars were ready to be junked by 120k miles. This is another diy job if you have a good jack and sturdy jack stands. If you don't feel comfortable going diy mode on the diff fluid change, buy 2 quarts full syn differential fluid at auto parts store (about $12/quart) and take the fluid in to local shop so you can just pay the 1 hr of labor they will charge you to change the diff fluid. On the LS I'd do this every 30-50k.

 

Here is the fluid transfer pump I used last week to suck out power steering fluid and add Mobile 1 Synthetic ATF .


I read somewhere in context of another make/model that you can keep doing this every 10K miles and you can keep fluid relatively clean without doing flushes.

 

If you buy those soap pump dispensers keep a couple for doing these tasks. Obviously rinse them out prior to using. They will not have the same pump volume as the one above so it will take more pumps to accomplish the job. That's what I use on the P&S and brake reservoir.

I siphon the top amounts of fluid in the brake reservoir so that the nasty stuff isn't being pushed through the ABS/TRAC when bleeding the brake system.