1990 LS400 power steering nightmare
03-01-15, 06:22 PM
#1
Driver School Candidate
Thread Starter
1990 LS400 power steering nightmare
I read some other post about the dreaded power steering repairs and most seem simple and labor intensive. When you love a well engineered car like a Lexus you will spend time taking care of it. Here is my nightmare. We have a leak that looks like coffee with creamer coming out of the driver side. Kinda like lots of air in the power steering fluid that puked all over the ground. A few days before it was lots of power steering fluid coming out of the passenger side originating right below the power steering pump on passenger side. The usual whining like cavitation was associated with this. I saw a post about a certain valve that can be substituted with a 14x1.5 plug and a slim gasket. That operation will be performed with this surgery. I like to bypass things if it will not destroy the vehicle. why lexus did anything like that is beyond me. We live in a place with sub zero temps so this i am aware of is a killer of power steering seals. i am also aware that there is a proper power steering fluid to use like DEXRON 3 and that was not used in this vehicle to my knowledge but will be after the repair is made. Are there seals on the power steering lines AKA hoses that need to be replaced that could also make a temporary fix till I can get this vehicle to a location with a lift or open pit. I am hearing nightmare stories about this affecting the alternator and why i have no idea but i did see that. My thoughts are that a certain valve and an o ring is shot and possibly a loose fitting on the rack itself. As the vehicle sits we have ZERO power steering as the entire system is now dry as we speak. BTW we have no Lexus dealer within 200 miles of here but we do have NAPA and O Reily's
03-02-15, 07:33 AM
#2
Welcome to Culb Lexus, seeing this is your first post. The original power steering components are the sore spot on these cars especially with the older Ls400s due to aged and weather conditions, otherwise these are well built and reliable cars. You're right about extreme cold weather, its NOT good on the rubber seals, heck here in Texas it dipped in the low 20s one day and my rack n pinion decided to call it quits. Few points I make(just my opinions if it was my car).
First you really want to fix the leaking reservoir because the atf WILL destroy the alternator. Its an easy fix, just replace the rubber o ring at the bottom of reservoir. Now I am assuming everything is original on your car like the pump, rack, and high pressure hose. Before replacing parts u could flush and bleed the system first, check here https://www.clublexus.com/forums/ls4...ystem-diy.html if that don't work here's what I would do if it was my car
1. I would replace the power steering pump immediately. My car(97Ls400) few years ago lost complete power steering, I put on a remanufactured PS pump I got my power steering back. Remember replace that o ring when doing this. If you can afford it get a brand new pump, its expensive but worth it, rock auto has one under $200 I believe. Also remove that air control valve on the pump, use a M18 bolt and washer from O Reilly's fits perfect and cap off the two ports on the intake. Optional: put some rtv on the threads of the M18 bolt
2. Replace the High pressure hose. The one that goes from the bottom of the pump around the oil pan to the rack if that makes sense. This hose cost over $300 at the dealer, but you can get one from o Reilly's or rock auto for much less. These are almost guaranteed to leak due to age and a master mech told me ATF is tough on these hoses, I believe him just from all the stories I read on here and mines leaked too, the rubber tends to rot out and crack.
3. Mines lasted til about 178,000 but get a remanufactured rack n pinion, or you could have a reputable shop to rebuild your old rack for you. I decided to have my rack rebuild for 150 and I am satisfied, my sterring is much much more better than before, way less whining sound(very slight at low speeds like less than 5mph) and very smooth turning. I posted a tutorial how I change my own rack, its not that bad, but I don't know how mechanical you are. https://www.clublexus.com/forums/ls4...-tutorial.html But that's what I would do, Pump and o-ring, high pressure hose, then the rack n pinion in that order or replace it all at same time like me and you'll have almost brand new steering feel. If u replace the rack, that a good time to replace the rack bushings. Also front o2 sensors. Don't forget about outer tie rods and ball joints if you need them replace. Call me crazy but I did replace these parts on my car, except the rack bushings, wish I did tho.
One last thing, keep using atf type 3, but in my car I am running fully synthetic power steering fluid made by preston, its the one for Asian cars. They claim its made for Toyota and Lexus high and low mileage cars, and it can be mixed with oem fluid already in the car, but do NOT mix fluids, if u do use it flush the old stuff out first. I know my car calls for atf type3, but even my master mech said its fine to run that PS fluid. You wouldn't believe how smooth and quite my steering is now. Mabey one day I might refill with atf but for right now its working perfectly fine. Sorry for long post, I got long winded hope it helps.
First you really want to fix the leaking reservoir because the atf WILL destroy the alternator. Its an easy fix, just replace the rubber o ring at the bottom of reservoir. Now I am assuming everything is original on your car like the pump, rack, and high pressure hose. Before replacing parts u could flush and bleed the system first, check here https://www.clublexus.com/forums/ls4...ystem-diy.html if that don't work here's what I would do if it was my car
1. I would replace the power steering pump immediately. My car(97Ls400) few years ago lost complete power steering, I put on a remanufactured PS pump I got my power steering back. Remember replace that o ring when doing this. If you can afford it get a brand new pump, its expensive but worth it, rock auto has one under $200 I believe. Also remove that air control valve on the pump, use a M18 bolt and washer from O Reilly's fits perfect and cap off the two ports on the intake. Optional: put some rtv on the threads of the M18 bolt
2. Replace the High pressure hose. The one that goes from the bottom of the pump around the oil pan to the rack if that makes sense. This hose cost over $300 at the dealer, but you can get one from o Reilly's or rock auto for much less. These are almost guaranteed to leak due to age and a master mech told me ATF is tough on these hoses, I believe him just from all the stories I read on here and mines leaked too, the rubber tends to rot out and crack.
3. Mines lasted til about 178,000 but get a remanufactured rack n pinion, or you could have a reputable shop to rebuild your old rack for you. I decided to have my rack rebuild for 150 and I am satisfied, my sterring is much much more better than before, way less whining sound(very slight at low speeds like less than 5mph) and very smooth turning. I posted a tutorial how I change my own rack, its not that bad, but I don't know how mechanical you are. https://www.clublexus.com/forums/ls4...-tutorial.html But that's what I would do, Pump and o-ring, high pressure hose, then the rack n pinion in that order or replace it all at same time like me and you'll have almost brand new steering feel. If u replace the rack, that a good time to replace the rack bushings. Also front o2 sensors. Don't forget about outer tie rods and ball joints if you need them replace. Call me crazy but I did replace these parts on my car, except the rack bushings, wish I did tho.
One last thing, keep using atf type 3, but in my car I am running fully synthetic power steering fluid made by preston, its the one for Asian cars. They claim its made for Toyota and Lexus high and low mileage cars, and it can be mixed with oem fluid already in the car, but do NOT mix fluids, if u do use it flush the old stuff out first. I know my car calls for atf type3, but even my master mech said its fine to run that PS fluid. You wouldn't believe how smooth and quite my steering is now. Mabey one day I might refill with atf but for right now its working perfectly fine. Sorry for long post, I got long winded hope it helps.
Last edited by LsG86; 03-02-15 at 09:20 AM.
03-03-15, 09:31 AM
#3
Driver School Candidate
Welcome to Culb Lexus, seeing this is your first post. The original power steering components are the sore spot on these cars especially with the older Ls400s due to aged and weather conditions, otherwise these are well built and reliable cars. You're right about extreme cold weather, its NOT good on the rubber seals, heck here in Texas it dipped in the low 20s one day and my rack n pinion decided to call it quits. Few points I make(just my opinions if it was my car).
First you really want to fix the leaking reservoir because the atf WILL destroy the alternator. Its an easy fix, just replace the rubber o ring at the bottom of reservoir. Now I am assuming everything is original on your car like the pump, rack, and high pressure hose. Before replacing parts u could flush and bleed the system first, check here https://www.clublexus.com/forums/ls4...ystem-diy.html if that don't work here's what I would do if it was my car
1. I would replace the power steering pump immediately. My car(97Ls400) few years ago lost complete power steering, I put on a remanufactured PS pump I got my power steering back. Remember replace that o ring when doing this. If you can afford it get a brand new pump, its expensive but worth it, rock auto has one under $200 I believe. Also remove that air control valve on the pump, use a M18 bolt and washer from O Reilly's fits perfect and cap off the two ports on the intake. Optional: put some rtv on the threads of the M18 bolt
2. Replace the High pressure hose. The one that goes from the bottom of the pump around the oil pan to the rack if that makes sense. This hose cost over $300 at the dealer, but you can get one from o Reilly's or rock auto for much less. These are almost guaranteed to leak due to age and a master mech told me ATF is tough on these hoses, I believe him just from all the stories I read on here and mines leaked too, the rubber tends to rot out and crack.
3. Mines lasted til about 178,000 but get a remanufactured rack n pinion, or you could have a reputable shop to rebuild your old rack for you. I decided to have my rack rebuild for 150 and I am satisfied, my sterring is much much more better than before, way less whining sound(very slight at low speeds like less than 5mph) and very smooth turning. I posted a tutorial how I change my own rack, its not that bad, but I don't know how mechanical you are. https://www.clublexus.com/forums/ls4...-tutorial.html But that's what I would do, Pump and o-ring, high pressure hose, then the rack n pinion in that order or replace it all at same time like me and you'll have almost brand new steering feel. If u replace the rack, that a good time to replace the rack bushings. Also front o2 sensors. Don't forget about outer tie rods and ball joints if you need them replace. Call me crazy but I did replace these parts on my car, except the rack bushings, wish I did tho.
One last thing, keep using atf type 3, but in my car I am running fully synthetic power steering fluid made by preston, its the one for Asian cars. They claim its made for Toyota and Lexus high and low mileage cars, and it can be mixed with oem fluid already in the car, but do NOT mix fluids, if u do use it flush the old stuff out first. I know my car calls for atf type3, but even my master mech said its fine to run that PS fluid. You wouldn't believe how smooth and quite my steering is now. Mabey one day I might refill with atf but for right now its working perfectly fine. Sorry for long post, I got long winded hope it helps.
First you really want to fix the leaking reservoir because the atf WILL destroy the alternator. Its an easy fix, just replace the rubber o ring at the bottom of reservoir. Now I am assuming everything is original on your car like the pump, rack, and high pressure hose. Before replacing parts u could flush and bleed the system first, check here https://www.clublexus.com/forums/ls4...ystem-diy.html if that don't work here's what I would do if it was my car
1. I would replace the power steering pump immediately. My car(97Ls400) few years ago lost complete power steering, I put on a remanufactured PS pump I got my power steering back. Remember replace that o ring when doing this. If you can afford it get a brand new pump, its expensive but worth it, rock auto has one under $200 I believe. Also remove that air control valve on the pump, use a M18 bolt and washer from O Reilly's fits perfect and cap off the two ports on the intake. Optional: put some rtv on the threads of the M18 bolt
2. Replace the High pressure hose. The one that goes from the bottom of the pump around the oil pan to the rack if that makes sense. This hose cost over $300 at the dealer, but you can get one from o Reilly's or rock auto for much less. These are almost guaranteed to leak due to age and a master mech told me ATF is tough on these hoses, I believe him just from all the stories I read on here and mines leaked too, the rubber tends to rot out and crack.
3. Mines lasted til about 178,000 but get a remanufactured rack n pinion, or you could have a reputable shop to rebuild your old rack for you. I decided to have my rack rebuild for 150 and I am satisfied, my sterring is much much more better than before, way less whining sound(very slight at low speeds like less than 5mph) and very smooth turning. I posted a tutorial how I change my own rack, its not that bad, but I don't know how mechanical you are. https://www.clublexus.com/forums/ls4...-tutorial.html But that's what I would do, Pump and o-ring, high pressure hose, then the rack n pinion in that order or replace it all at same time like me and you'll have almost brand new steering feel. If u replace the rack, that a good time to replace the rack bushings. Also front o2 sensors. Don't forget about outer tie rods and ball joints if you need them replace. Call me crazy but I did replace these parts on my car, except the rack bushings, wish I did tho.
One last thing, keep using atf type 3, but in my car I am running fully synthetic power steering fluid made by preston, its the one for Asian cars. They claim its made for Toyota and Lexus high and low mileage cars, and it can be mixed with oem fluid already in the car, but do NOT mix fluids, if u do use it flush the old stuff out first. I know my car calls for atf type3, but even my master mech said its fine to run that PS fluid. You wouldn't believe how smooth and quite my steering is now. Mabey one day I might refill with atf but for right now its working perfectly fine. Sorry for long post, I got long winded hope it helps.
Now I know what's next on ps leak that's driving me crazy
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