Run power steering pump dry?

[megatron]

Hi...

I'm attempting to change the power steering fluid on my 2007 Pilot and the service manual and a couple of other threads have both mentioned that you disconnect the return hose to the reservoir and put it in a bucket and then start your engine and turn steering lock to lock until no more fluid runs out.

My question is this... once I begin doing that, the PS pump sequels like you wouldn't believe! And I wasn't close to getting all the fluid out yet. I turned off the engine right away fearing I am wearing away my pump's internals by running it dry.

Is this normal to do and safe??? Or am I missing something here? I must be doing something wrong. I can't imagine it's ok to run a pump even for a short time without any fluid in it.

Can someone enlighten me? Thanks!

[ltp646]

I don't know the about the specific procedures that you followed, but they don't sound too good. How about keep filling the PS reservior with fresh fuild until the clean fluid comes out of the return hose into the bucket, reconnect the return hose, and fill the reservior to the proper level? This suggestion is just based on how I change the brake fluid. As for PS, I just remove as much fluid from the reservior as I can and then fill it with new fluid.

[N_Jay]

Ouch,

I would NEVER recommend doing that.

IF you are really interested in changing "ALL" the fluid, I would disconnect the return hose, and start the engine just till the reservoir is empty.
Then clean it out the reservoir and fill with new fluid and start it up having someone keep topping up the fluid as you turn the wheel from one side to the other.

[theirishscion]

Certainly sounds horrible, but if the factory service manual states it, who am I to argue? I guess?

I like N-Jay's idea (I've been saying that a lot recently), if you have the manpower available. With that said;

If this is representative of the Honda PS pump, then I imagine the squealing is just what the pump sounds like when running on air, rather than some nasty metal to metal abrasion going on. The vanes in this type of pump aren't made of metal. Assuming you can get the system drained in less than a minute, I imagine the pump is never actually running unlubricated either. Probably nothing at all to worry about.

If you want to reduce the stress on the pump during the procedure, I'd suggest lifting the front wheels off the ground so there is no weight on them and hence no real work for the power steering pump to do. There is a central jacking point under the 2009+ Pilots, I imagine there's something under the 1st gen as well.

[N_Jay]

Wow, just checked and factory manual does say to do that.

Why are you changing the fluid?
Maybe the squealing is the fact he pump is already on its way out.

[theirishscion]

Originally Posted by N_Jay

Wow, just checked and factory manual does say to do that.

Why are you changing the fluid?
Maybe the squealing is the fact he pump is already on its way out.

I wouldn't bet on it, I've heard vane-compressors howl before under the right circumstances, without having anything wrong with them. Think about the sound of an air impact wrench, which is the same thing, except running in reverse, air in one end, torque out the other.

[megatron]

Originally Posted by N_Jay

Wow, just checked and factory manual does say to do that.

Why are you changing the fluid?
Maybe the squealing is the fact he pump is already on its way out.

I'm changing the fluid because it looks really dark and kinda gunky. I originally started by just doing the turkey baster in the reservoir and refill x 3 like you do with the tranny fluid, but even after 4 times of doing that, the fluid was still dark brown and didn't lighten up much. That's when I looked into actually trying to get all the fluid out and came across the directions in the service manual.

I don't think the noise is telling me that the pump is on its way out already because it is perfectly fine with fluid (no noise at all) and it only squeals when I start emptying it of fluid. I'm just wondering if I should just ignore the noise and continue on until all the fluid is out or whether the noise is indicative of something going wrong. It just sounds very bad... that's why I am afarid to continue. Perhaps the noise goes away after all the fluid is out??? I don't know... just wondering if anyone else has done this before so they can tell me what is supposed to happen when so I don't get all freaked out.

[rocky]

Yikes what a horrible method. However what if you were introducing fresh fluid at the same time, I might be happier.

What happened when you simply removed the return with the engine off, and topped up into that line, reinstalled it, checked the reservoir? Then started the engine momentarily to circulate the fluid

[belundy]

You have to run a rigid vane pump quite a while without fluid to cause significant vane wear--the only force on the vanes is centrifugal when it is cavitating without fluid. There is a pool of fluid the vanes pick up and sling around maintaining a lubricating film. In other words, the Honda engineer knew exactly what he was recommending.

Of course, you can just run the engine until the pump just starts to spit (use clear hose and locate it so you can peek through the cowl/hood gap.). Add fluid to reservoir and repeat.

Be sure to back wash the reservoir (removed from vehicle) to clean the pickup screen.

[haileyian]

Hi Folks,
I actually used a turkey baster to siphon the fluid from the reservoir then filled it with new fluid and then ran the engine, going end to end, to move the fluid. I repeated this process a few times until I had only clean fluid left.

[94eg!]

The sound is air being moved through the pump and steering gearbox. It's totally normal and you won't damage anything. I've done this on several Hondas to replace the fluid. Your good to go.

Don't waste your time siphoning or basting out the fluid. Your supposed to empty it all out and check to see if the screen built into the bottom is clogged. Do it as said in the manual and everything will be fine.

BTW: The last instruction says if your fluid is still dirty after doing this once, do it a second time.

[megatron]

Originally Posted by 94eg!

The sound is air being moved through the pump and steering gearbox. It's totally normal and you won't damage anything. I've done this on several Hondas to replace the fluid. Your good to go.

Don't waste your time siphoning or basting out the fluid. Your supposed to empty it all out and check to see if the screen built into the bottom is clogged. Do it as said in the manual and everything will be fine.

BTW: The last instruction says if your fluid is still dirty after doing this once, do it a second time.

Thanks for the verification that it is safe to do! Glad someone has done it before. Can I ask you one other question, since you have gone through this... does the noise go away once all the fluid is out??? Or does it always make the noise until fluid is put back in?

[94eg!]

I don't remember if the sound goes away when the fluid is out, but I do remember you can no longer turn the steering wheel.

I also remember that it's a huge amount of fluid that comes out. And since the pump is sucking air, it's all foamy. So use something like a 1 liter bottle or a large juice bottle to catch it. It also comes out with considerable force so be sure the bottle and tube your using are secured enough to stay standing while your inside rowing the wheel.

It also takes some time to get the new fluid back into the system and filled. You top of the reservoir and start the car. It immediately sucks the thing dry. You will need to shut the car off and fill it one more time. Then you can go inside the car, start it, and row the steering wheel back & forth. Just keep in mind the pump will be making lots of noise the entire time. It will go quiet once all the air is worked out.

BTW: It's normal to have a quick squeal the first time you start the car after replacing the fluid. It's just a small bit of air stuck in the lines. It shouldn't come back after that.

One more tip: Since you already have the system drained, it's a good time to replace the suction hose o-ring at the pump. You only need to remove one 10mm bolt and the hose pops right off the pump. The original o-ring will be black, and the new replacment part will be orange. The black o-ring eventually shrinks in the cold winter weather, and the PS pump will start sucking air past the seal one morning when you first start it up. This causes the reservroir to slightly overlflow (because of bubbles), which seems like a leak but it's not. This problem is SUPER common in Honda/Acuras. I personally had to replace 3 of these o-rings (my 05 TL, wife's 04 Pilot, and sisters 03 RSX). You can always tell by looking into the reservoir with the engine running. If you see bubbles, your o-ring is bad.

Here is a great DIY for this on a V6 accord (the same as Pilot): DIY Power Steering Pump O-Ring TSB - Drive Accord Honda Forums

The o-ring is part number 91345-RDA-A01 and cost less ~$1 at even the most expensive dealership. All Honda & Acura dealers will stock this part cause this is so common:

91345-RDA-A01 - Honda O-RING (13.0X1.9)

It's #17 in the picture:

[megatron]

Thanks for the detailed info! It's really helpful! Final question, did you jack the front end of the car up to do this? In other words, are you turning the wheel with the tires on the ground, or in the air?

[94eg!]

No. I just turned it in the garage on the floor per the manual.