I replaced the high pressure steering line on my 99 RX300 in the last month. We had a slow leak for many years which got worse and worse, to the point it could not be avoided any longer. For the first several weeks after replacing the line the steering system has worked well. The level in the reservoir has not changed and I haven't witnessed any leaking both immediately after the replacement or to date. I did attempt to bleed the system by turning on the car and rotating the wheels back and forth several times. It's been about a month and now the steering wheel has some obvious play in it. My wife said it was fine one morning and had an issue the next.

I have since learned that I probably should have not turned the car on when rotating the wheels. I also don't believe I jacked the car up and it was facing slightly downhill. Can air in the line cause wander in the steering system suddenly, or is this most likely a steering rack issue?

Marc

 

Air in the P/S system is going to make the steering firm and difficult to steer usually wandering is an issue with the alignment. It’s kinda weird that it has just become worse? Unless someone clipped a curb and hasn’t fessed up or something like that

 

Thanks dwoods801 for your reply. When you say alignment are you referring to the suspension components, specifically the inner and outer tie rods? Do you believe that the issue could also be related to the steering rack itself? I'll be testing the wheels for movement left to right later this week.

 

I had the rack replaced several years ago on my 99RX because it kept slightly wandering when at highway speeds. It was a RockAuto reman. My otherwise excellent suspension shop could not solve the problem with alignments, and suggested the rack might be at fault. It was the culprit, and now the car no longer "wanders". I did not do the install, the shop did.

 

IN bleeding the air out, it helps to lift the front wheels off as the pump with air does not need to work hard. IN the strictest terms you could have shortened the pump life by fraction of an hour. It all depends on how long the pump whined with air in the system. Bleeding process is to turn the steering all the way to the right and then all the way to the left and back again. Once the air is removed the circuit has incompressible fluid and steering control then has no voids.

I woulds start by observing play in the mechanical components. You lift one front wheel and push/pull from 3oclock to 9oclock pretty aggressively. If there is play then some steering link is worn out [an assistant can be the spotter].

There are other suspension components, but imho with at home equipment and even with standard post lifts it is hard to diagnose. Special lift [typically at alignment shops] can transfer weight at different points and can tell you that which suspension component is worn. A good alignment shop will perform this test before confirming/fixing alignment.

After the above [air in the circuit, steering linkage, suspension, alignment], the issue can be in the tire(s), or the rack.

One can swap the wheels front to back to see if the problem is due to wheels [this can be non-conclusive too as the other tire may have issues].

It is strange that you only changed the pressure pipe and you encountered the problem as other components were not tampered with.

On a side note, Lexus at times puts a small valve [resembles ball of a bearing] inside the cavity where the high pressure hose goes into the pump. Hopefully you did not loose it when you swapped the hose.

Salim

 

Hello Salim,

May I ask if you can describe what this valve/ball bearing looks like and where it would be located. I did not see this when I replaced the line.

 

It's a long shot but worthwhile to check the steering wheel nut torque.

 

Best description is that it is like an inline vale, looks like a pallet and was in the pump side female thread hole. If you saw one and discarded it then it would be something to pursue, else ignore my post as I am going by memory and have worked various Lexus models.

Salim

 

I think you’re describing a banjo bolt? It’s a unique bolt that is used to bolt a pressure line onto a pump. The end of the pressure line will have a fitting for folios to flow through and also have a circular hole for a bolt to attach it to the pump and it will also have a special washer that seals both sides of the fitting. You need to replace this washer anytime it’s removed because when it’s installed, it will twist to seal up and can’t be reused.

 

It was a like a slug inside the hole of the pressure line fitting, and it fell out when I turned the pump upside down [when the hole faced down] It was like a check valve or pressure reducing thing. As stated in my post, I can not vouch that it applies to RX. I grew with a diesel and very familiar with banjo bolts.

Salim

 

hmm, I am not familiar with what your describing but it seems to be unrelated if he didn’t find it when removing the old P/S line. Has the OP determined if the problem is in the P/S system? Or if it’s a component in the steering or suspension?