The First Gen Power Steering Bible
01-26-07, 04:51 PM
#1
Lexus Champion
Thread Starter
The First Gen Power Steering Bible
Well I've been getting a lot of PMs lately about various power steering issues, and I've noticed that in the last month atleast 10 new first gen LSes have appeared on this board, so I thought I'd take all the power steering info that there is on this board and organize it into one place. Please read this article for inaccuracies and help me correct them. Also if you have more info to contribute to this thread, great! I'll continue editing the first post to organize it as much as possible.
The first generation LS400 has proven to be a very reliable car. However, its not perfect. There are some common problems that we've become familiar with. One of the main failure points in the car is the power steering system. Any high mileage car that has not faced these issues will most probably see them soon.
Before you deal with anything regarding your power steering, read this thread first. This is a work in progress, and hopefully I'll be able to add pictures and things like that later, but its just a start. Please offer any suggestions. I've decided to organize it by problem/topic.
Table of Contents
1. "Whining" noises from the front, especially during turning/cornering
2. Power steering is leaking, white smoke on startup
3. Strange intermittent PS problems
4. Solenoid Cleaning Procedure
5. Power Steering Pump Replacement
1. "Whining" noises from the front, especially during turning/cornering
If you hear whining noises from your power steering it is becuase the fluid is most probably low. Simply top off your power steering fluid and monitor it. If you find that you have to refill it often, you have some kind of leak. Open up the hood and check for any visible leaks. This is important! If your power steering pump is leaking, fluid will drip onto the alternator, and this will lead to a very costly repair. Another way to check is to garage park the car overnight and check for any puddles on the floor. If you have the tools, jack the car up and remove the under-engine cover and see if you notice any leaks from there.
Another member, (PureDrifter) suggested using an UV dye type of substance inside the PS fluid and then using a blacklight to try and find it. I don't know of any dyes that can be used, but it is worth investigation.
If you find that you are constantly filling up power steering fluid, (atleast once a week), and you can't find and visible evidence of the fluid leaking, the culprit is most probably the idle-up valve on your pump. When this valve malfunctions, power steering fluid is sucked into the intake manifold and burned in the engine. If a considerable amount of fluid is leaking, you will notice white smoke when you start the engine.
When I had this problem, I had to fill half of my PS resevoir almost every 3 days, and when I started the car in the morning, it produced enough thick white smoke to fill up the entire garage. See the section below.
2. Power steering is leaking, white smoke on startup
As mentioned above, a common problem on the first generation LS400 is a power steering leak in the Idle Control Valve. This valve is on the pump in one of the hoses that runs from the pump to the intake manifold. When this valve malfunctions, PS fluid is leaked into the engine and burned.
Often high mileage LS400s have rebuilt, remanufactured, or brand new power steering pumps. This valve is not included with a new pump, so even if you have a rebuilt one, you may still encounter this problem.
This valve is used to regulate the steering feel. Essentially, when the car is driving faster, the steering feel is tightened, and when the car is slower, there is more steering boost to aid effort-less turning. The part costs about $140 from the Lexus dealer. It is often referred to as the idle-up valve, the idle-control valve, and I've even heard it being called the air-control valve.
If you find yourself having this problem, you are faced with two options. You can replace the valve which may take about 3 hrs of labor (my mechanic had to take quite a bit out to get to the pump). You can also simply plug the valve with something. I had mine plugged for a few days, and the difference in having this part plugged is unnoticeable. Other members have attested to this. More info about the valve, courtesy of lorenzo816
Picture of the valve:
Lorenzo also writes about how he plugged his PS pump instead of buying a new valve:
That post can be found here:
pito had different experiences when attempting the same repair, and his mechanic suggested an alternate method to plugging it:
I purchased the recommended bolt from autozone and found that it didnt work for me. Well, my crafty mechanic takes the old valve and rips out the metal threaded parts from the rest of the valve. He then welds in some metal with the metal pin at the bottom and made a sealed off valve so to speak. Well after this and capping the two vacuum lines, I have no smoke issues and the idle is as smooth as ever. Me and my LS are now on good terms.
His post can be found here
3. Strange intermittent PS problems
Many users have posted some strange intermittent problems. Their power steering will often seem to stop working. At times it will work well, and at times it will seem to completely shut off. In many of these cases, the culprit has been the screen that protects the steering solenoid. There are two screens in the LS power steering system. There is one screen at the bottom of the resevoir on the power steering pump. There is also a screen protecting the solenoid in the steering rack as mentioned above. If you have strange problems where your PS boost seems to give out at times, have a mechanic diagnose your system and start by cleaning the solenoid. If the mechanic suggests you get a new pump, do not listen. Start by getting this screen cleaned and see if it fixes the problem. Along with cleaning this screen, a power steering system flush with Dexron III fluid will also help.
If your solenoid needs replacement... there is no easy way around this. 914LPS has a great post on this. His experiences in 2004 were that the solenoid could only be purchased as part of the valve on the rack for about $500, or in a completely new rack with the valvle and the Solenoid for about $400. In the same post, 914lps talks about how when his PS pump was replaced, the solenoid was cleaned, but the screens in the pump were not, and so they deteriorated.
This is a link to a great post about the steering solenoid:
4. Solenoid Cleaning Procedure
This info has been taken directly from from the post linked above by 914Lps. He details the procedure he used to check the solenoid electrically as well as how to clean it. That info has been duplicated here to be comprehensive. Thanks a lot 914lps! Link to original post and other comments.
How to service Solenoid:
Disconnect the wires
Take a sharpie and mark a registration line across the nut & on the steering rack for positioning.
The Solenoid is connected by a thin nut, use either very thin channel lock pliers or just take a flat screwdriver or small chisel and "tap" the nut to loosen - then remove by hand.
Behind the solenoid or attached to it, will be the screen and a gasket, just be careful with it and remove. You'll loose 1/4 quart+ of PS fluid....a little messy, so be ready!
Clean the screen, replace, and tighten solenoid back to registration mark. Tap it back tight with the screwdriver or chisel you used.
Good cleaner to use:
Suggest 3-M Adhesive Cleaner instead of Brake Cleaner. The brake stuff is fairly 'mean' with toluene in it !!!! And it evaporates too fast for an overall cleaner. The 3-M product # is 08984 in a qt. or 08987 in a spray can
Reconnect electrical.
Then flush system.
Directions on flushing system:
http://us.lexusownersclub.com/forums...ower++steering
Or:
http://www.lexls.com/psflush.html
It takes about 7 to 8 quarts to flush most systems clean one time. Use Dextron III Transmission fluid. Valvoline makes a good one for High Mileage cars.
After flushing system it is best to re-clean the screen again.
Checking the Solenoid electrically:
Measure the resistance on the solenoid. It should be between 6 and 11 ohm. After this check the operation. Connect battery terminals to the solenoid. when you look at the connector the left one is - and right one is +. Check that the solenoid makes clicks sound.. don’t apply voltage for more then 30 sec otherwise you will burn it.. if you have to repeat the procedure wait till it cools down so you can touch it with your hand. If there is no click sound replace the pressure control valve with the solenoid valve.
Checking the power steering ECU. There is a PPS ECU specifically put there for the purpose of switching the solenoid on and off. Its located under the steering wheel right next to tilt & telescopic ECU. Check the voltage between the ECU - and ground connectors. - connector is in the upper left corner and ground is in lower left corner if you look at the connector while its plugged in into the ecu. voltage should be between 0.15 and 0.2 V with the engine idling. lift the car and put it in Drive. check the voltage while car running at 60 mph. it should be between 0.04 and 0.16 V. If its no you have to get yourself a new ECU. Don’t forget to check the wire from the ECU to the solenoid and make sure its ok might be just a wire problem
Picture of solenoid and nut (in this photo here he asks is this the Solenoid and do you pound here, the answer is yes) :
http://us.lexusownersclub.com/forums...cmd=si&img=217
If needed rebuild of Power steering pump:
http://us.lexusownersclub.com/forums...showtopic=9851
If needed information on the Air Control Valve (located on the side of the Power Steering Pump).:
http://us.lexusownersclub.com/forums...6&hl=air+valve
and:
http://us.lexusownersclub.com/forums...opic=10364&hl=
and this guy states he can get parts… I have no idea if he is good or bad…….
https://www.clublexus.com/forums/show...hreadid=125839
5. Power Steering Pump Replacement
If you've found that your power steering pump is giving out, leaking, or have been told by a mechanic/dealer that it needs to be replaced, you're not alone. Many people with first gens have gone through this problem. First, make sure that you don't have any of the problems mentioned above before getting this expensive repair done.
You have several options. You can purchase a new pump from the dealer (most expensive), buy a remanufactured pump (cheaper), or attempt to rebuild the pump yourself (even cheaper, but will require a lot of labor on your part).
Great link from LexLS on rebuilding a pump yourself.
The first generation LS400 has proven to be a very reliable car. However, its not perfect. There are some common problems that we've become familiar with. One of the main failure points in the car is the power steering system. Any high mileage car that has not faced these issues will most probably see them soon.
Before you deal with anything regarding your power steering, read this thread first. This is a work in progress, and hopefully I'll be able to add pictures and things like that later, but its just a start. Please offer any suggestions. I've decided to organize it by problem/topic.
Table of Contents
1. "Whining" noises from the front, especially during turning/cornering
2. Power steering is leaking, white smoke on startup
3. Strange intermittent PS problems
4. Solenoid Cleaning Procedure
5. Power Steering Pump Replacement
1. "Whining" noises from the front, especially during turning/cornering
If you hear whining noises from your power steering it is becuase the fluid is most probably low. Simply top off your power steering fluid and monitor it. If you find that you have to refill it often, you have some kind of leak. Open up the hood and check for any visible leaks. This is important! If your power steering pump is leaking, fluid will drip onto the alternator, and this will lead to a very costly repair. Another way to check is to garage park the car overnight and check for any puddles on the floor. If you have the tools, jack the car up and remove the under-engine cover and see if you notice any leaks from there.
Another member, (PureDrifter) suggested using an UV dye type of substance inside the PS fluid and then using a blacklight to try and find it. I don't know of any dyes that can be used, but it is worth investigation.
If you find that you are constantly filling up power steering fluid, (atleast once a week), and you can't find and visible evidence of the fluid leaking, the culprit is most probably the idle-up valve on your pump. When this valve malfunctions, power steering fluid is sucked into the intake manifold and burned in the engine. If a considerable amount of fluid is leaking, you will notice white smoke when you start the engine.
When I had this problem, I had to fill half of my PS resevoir almost every 3 days, and when I started the car in the morning, it produced enough thick white smoke to fill up the entire garage. See the section below.
2. Power steering is leaking, white smoke on startup
As mentioned above, a common problem on the first generation LS400 is a power steering leak in the Idle Control Valve. This valve is on the pump in one of the hoses that runs from the pump to the intake manifold. When this valve malfunctions, PS fluid is leaked into the engine and burned.
Often high mileage LS400s have rebuilt, remanufactured, or brand new power steering pumps. This valve is not included with a new pump, so even if you have a rebuilt one, you may still encounter this problem.
This valve is used to regulate the steering feel. Essentially, when the car is driving faster, the steering feel is tightened, and when the car is slower, there is more steering boost to aid effort-less turning. The part costs about $140 from the Lexus dealer. It is often referred to as the idle-up valve, the idle-control valve, and I've even heard it being called the air-control valve.
If you find yourself having this problem, you are faced with two options. You can replace the valve which may take about 3 hrs of labor (my mechanic had to take quite a bit out to get to the pump). You can also simply plug the valve with something. I had mine plugged for a few days, and the difference in having this part plugged is unnoticeable. Other members have attested to this. More info about the valve, courtesy of lorenzo816
Picture of the valve:
Lorenzo also writes about how he plugged his PS pump instead of buying a new valve:
Originally Posted by lorenzo816
....."Oh! And While I was in there... I yanked that Damn ICV valve out of the Power steering pump. You can
reach it from the bottom with a 17mm opened ended wrench. Moving it ever so slowly, it will come out and drop fluid so be ready for it.
Replaced it with a 14 x 1.5 plug and slim gasket from Pep Boys. Yeah, it idles down when steering is tilt, but who cares? I don't have to spend another $100 on another friggin part. Don't forget to cap the vacuum lines too boys and girls."
reach it from the bottom with a 17mm opened ended wrench. Moving it ever so slowly, it will come out and drop fluid so be ready for it.
Replaced it with a 14 x 1.5 plug and slim gasket from Pep Boys. Yeah, it idles down when steering is tilt, but who cares? I don't have to spend another $100 on another friggin part. Don't forget to cap the vacuum lines too boys and girls."
pito had different experiences when attempting the same repair, and his mechanic suggested an alternate method to plugging it:
Originally Posted by pito
I purchased the recommended bolt from autozone and found that it didnt work for me. Well, my crafty mechanic takes the old valve and rips out the metal threaded parts from the rest of the valve. He then welds in some metal with the metal pin at the bottom and made a sealed off valve so to speak. Well after this and capping the two vacuum lines, I have no smoke issues and the idle is as smooth as ever. Me and my LS are now on good terms.
3. Strange intermittent PS problems
Many users have posted some strange intermittent problems. Their power steering will often seem to stop working. At times it will work well, and at times it will seem to completely shut off. In many of these cases, the culprit has been the screen that protects the steering solenoid. There are two screens in the LS power steering system. There is one screen at the bottom of the resevoir on the power steering pump. There is also a screen protecting the solenoid in the steering rack as mentioned above. If you have strange problems where your PS boost seems to give out at times, have a mechanic diagnose your system and start by cleaning the solenoid. If the mechanic suggests you get a new pump, do not listen. Start by getting this screen cleaned and see if it fixes the problem. Along with cleaning this screen, a power steering system flush with Dexron III fluid will also help.
If your solenoid needs replacement... there is no easy way around this. 914LPS has a great post on this. His experiences in 2004 were that the solenoid could only be purchased as part of the valve on the rack for about $500, or in a completely new rack with the valvle and the Solenoid for about $400. In the same post, 914lps talks about how when his PS pump was replaced, the solenoid was cleaned, but the screens in the pump were not, and so they deteriorated.
This is a link to a great post about the steering solenoid:
4. Solenoid Cleaning Procedure
This info has been taken directly from from the post linked above by 914Lps. He details the procedure he used to check the solenoid electrically as well as how to clean it. That info has been duplicated here to be comprehensive. Thanks a lot 914lps! Link to original post and other comments.
How to service Solenoid:
Disconnect the wires
Take a sharpie and mark a registration line across the nut & on the steering rack for positioning.
The Solenoid is connected by a thin nut, use either very thin channel lock pliers or just take a flat screwdriver or small chisel and "tap" the nut to loosen - then remove by hand.
Behind the solenoid or attached to it, will be the screen and a gasket, just be careful with it and remove. You'll loose 1/4 quart+ of PS fluid....a little messy, so be ready!
Clean the screen, replace, and tighten solenoid back to registration mark. Tap it back tight with the screwdriver or chisel you used.
Good cleaner to use:
Suggest 3-M Adhesive Cleaner instead of Brake Cleaner. The brake stuff is fairly 'mean' with toluene in it !!!! And it evaporates too fast for an overall cleaner. The 3-M product # is 08984 in a qt. or 08987 in a spray can
Reconnect electrical.
Then flush system.
Directions on flushing system:
http://us.lexusownersclub.com/forums...ower++steering
Or:
http://www.lexls.com/psflush.html
It takes about 7 to 8 quarts to flush most systems clean one time. Use Dextron III Transmission fluid. Valvoline makes a good one for High Mileage cars.
After flushing system it is best to re-clean the screen again.
Checking the Solenoid electrically:
Measure the resistance on the solenoid. It should be between 6 and 11 ohm. After this check the operation. Connect battery terminals to the solenoid. when you look at the connector the left one is - and right one is +. Check that the solenoid makes clicks sound.. don’t apply voltage for more then 30 sec otherwise you will burn it.. if you have to repeat the procedure wait till it cools down so you can touch it with your hand. If there is no click sound replace the pressure control valve with the solenoid valve.
Checking the power steering ECU. There is a PPS ECU specifically put there for the purpose of switching the solenoid on and off. Its located under the steering wheel right next to tilt & telescopic ECU. Check the voltage between the ECU - and ground connectors. - connector is in the upper left corner and ground is in lower left corner if you look at the connector while its plugged in into the ecu. voltage should be between 0.15 and 0.2 V with the engine idling. lift the car and put it in Drive. check the voltage while car running at 60 mph. it should be between 0.04 and 0.16 V. If its no you have to get yourself a new ECU. Don’t forget to check the wire from the ECU to the solenoid and make sure its ok might be just a wire problem
Picture of solenoid and nut (in this photo here he asks is this the Solenoid and do you pound here, the answer is yes) :
http://us.lexusownersclub.com/forums...cmd=si&img=217
If needed rebuild of Power steering pump:
http://us.lexusownersclub.com/forums...showtopic=9851
If needed information on the Air Control Valve (located on the side of the Power Steering Pump).:
http://us.lexusownersclub.com/forums...6&hl=air+valve
and:
http://us.lexusownersclub.com/forums...opic=10364&hl=
and this guy states he can get parts… I have no idea if he is good or bad…….
https://www.clublexus.com/forums/show...hreadid=125839
5. Power Steering Pump Replacement
If you've found that your power steering pump is giving out, leaking, or have been told by a mechanic/dealer that it needs to be replaced, you're not alone. Many people with first gens have gone through this problem. First, make sure that you don't have any of the problems mentioned above before getting this expensive repair done.
You have several options. You can purchase a new pump from the dealer (most expensive), buy a remanufactured pump (cheaper), or attempt to rebuild the pump yourself (even cheaper, but will require a lot of labor on your part).
Great link from LexLS on rebuilding a pump yourself.
Last edited by Suneet; 01-26-07 at 08:46 PM.
The following 3 users liked this post by Suneet:
01-26-07, 07:02 PM
#2
Very insightful and I think will be very helpful to all first gen LS owners. Thanks for taking the time to organize the "Holy Grail" of power steering, now all we need is one of out helpful mods to post it as a sticky for reference.
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ls400newbs (07-12-21)
03-13-07, 06:33 PM
#7
Driver School Candidate
Very Helpful
I am new to this forum and I want to say that the info in this thread really helped me out a lot. I actually just bought a 93 LS just recently and it had the problem of smoking at start up and using power steering fluid. The guy I bought the car from had told me that the power steering pump was going bad and that it was going to cost me about a grand to fix, and after reading this thread and about 140 dollars later the smoke is gone and the car idles a lot smoother. The valve is also called the "air control valve" as per the lexus dealer. I will also try to locate the part number for the valve so maybe someone can locate it without having to go to the dealership to purchase it. I also found it easier to remove the valve from underneath the car by also disconnecting the power steering line thats connected to the pump it will give you more room to move the wrench to remove and install the the valve.
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SloRolller (12-12-20)
Trending Topics
03-14-07, 11:34 AM
#8
You are very helpful as well
I am new to this forum and I want to say that the info in this thread really helped me out a lot. I actually just bought a 93 LS just recently and it had the problem of smoking at start up and using power steering fluid. The guy I bought the car from had told me that the power steering pump was going bad and that it was going to cost me about a grand to fix, and after reading this thread and about 140 dollars later the smoke is gone and the car idles a lot smoother. The valve is also called the "air control valve" as per the lexus dealer. I will also try to locate the part number for the valve so maybe someone can locate it without having to go to the dealership to purchase it. I also found it easier to remove the valve from underneath the car by also disconnecting the power steering line thats connected to the pump it will give you more room to move the wrench to remove and install the the valve.
Thanks for your input.
03-15-07, 03:44 PM
#9
Driver School Candidate
air control valve
Yes I did put the part in myself, when I went to the lexus dealership I seen a sign that said that they charge $99.50 an hour for misc. maintenance and that is way to much to pay when it can be done yourself. The $140 I said was including the part and the powersteering fluid, because the part costed me $132.23 from Lexus. The part # for the Air Control Valve is 17630-16040. I am not sure if the valve will work with the 90-91 LS, but give Lexus a call and I am sure they will be able to let you know if it is the same part. When I went to Toyota to find the part I didn't have the part # so they weren't able to look it up, and when I called Lexus they wouldn't give me the part # over the phone. So I am not sure if you can get it from Toyota. I hope this part # serves to be useful to anyone in the future.
Last edited by Mr. LS400; 03-15-07 at 04:04 PM.
03-19-07, 01:05 PM
#10
Yes I did put the part in myself, when I went to the lexus dealership I seen a sign that said that they charge $99.50 an hour for misc. maintenance and that is way to much to pay when it can be done yourself. The $140 I said was including the part and the powersteering fluid, because the part costed me $132.23 from Lexus. The part # for the Air Control Valve is 17630-16040. I am not sure if the valve will work with the 90-91 LS, but give Lexus a call and I am sure they will be able to let you know if it is the same part. When I went to Toyota to find the part I didn't have the part # so they weren't able to look it up, and when I called Lexus they wouldn't give me the part # over the phone. So I am not sure if you can get it from Toyota. I hope this part # serves to be useful to anyone in the future.
I am getting the p/s pump replaced next week. If that doesn't fix my leakage problem, I will have to get the air control valve. I just told my mechanic the solenoid should be cleaned as well. Not sure how much extra work that is. I guess Lexus dealership always cleans the solenoid every time they replace a power steering pump.
It's amazing how common this problem is on the LS400. A lot of people I talk to are amazed that the p/s pump ever goes out. On a Lexus, it's almost automatic around the 150K point.
I guess, if you want the smoothest ride ever, it's gonna hit your wallet every once in awhile. I'm not complaining.
03-19-07, 11:42 PM
#11
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Cruisin101 (06-30-18)
04-01-07, 03:41 PM
#13
Driver School Candidate
Join Date: Apr 2007
Location: wa
Posts: 4
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Leaking fluid and smoke upon start-up
Thanks so much for the steering string. Had same problem. Tried stop leak goop, not much success. Two mechanics said I needed a new rack and pinion as the boots were fluid filled. ('91 LS400 140,000 miles) $1400 later for a rebuilt rack, still same problem. Showed this suggested repair to mechanic (replace/remove valve) Seems to have done the trick. No problem. Steering is like new. Mechanic thanked me and didn't charge for the fix. Question?? How does steering fluid get into the engine? Japanese conspiracy?
