B4V Power steering fluid is shooting everywhere.

[slam]

B4V with 330k miles.

I got a condition where the power steering fluid is foaming up and shooting out of the reservoir. In addition to making a mess and growling like mini-Chewbacca at the pump, it killed my battery by getting PS fluid in the battery overflow nipple.

Bleeding the PS system doesn't seem to help, as soon as the car starts the reservoir starts to foam, and in a minute is overflowing.

I did notice the reservoir filter is cracked at the base and won't stay in place, but that seems unlikely to be the main cause.

Is this a dying pump?

And can I buy the little filter solo or do I need to get whole new reservoir?

 

[Mongler98]

If properly flushing it does not fix it, check for leaks on the pump input side, possible that its sucking air. Otherwise the pump might be toast. I dont recall ever noting that a pump failure symptom is like what you describe though. Might be a issue with a clogged line building pressure and backing out the pump?

 

[Abacus]

Reservoir filter? It should just be a screen and not a filter. Can you post pictures?

 

[slam]

The reservoir filter is a little tower. It fits over the first two digits of my pinky pretty good, so maybe an inch wide by two inches tall. It fits over a nub at the bottom of the reservoir on the output side. This is an Autohauzer replacement reservoir if I recall correctly. I'll post pics later today.

Could I have sucked in an obstruction? Maybe a bit of foil seal from a fluid bottle? I'm wondering if an input blockage would foam like this.

 

[Abacus]

I am interested in pictures because it sounds like someone swapped something in that wasn't needed nor there originally. It sounds like your pump is cavitating, taking air out of the fluid and aerating it. Any restriction on the feed line will cause lots of problems downstream, and everything is downstream. Since it's a closed system there is no filter needed or warranted. The pump provides a TON of flow, and you can see the flow strength through the top of the reservoir when it's running.

And just to be clear, the 'screen' I referenced is not metal, but rather a fixed plastic lower piece that is part of the reservoir itself. In the below picture you can just see the black line about an inch up from the bottom. It is designed to keep debris like the foil you mentioned out of the fluid path. There should be the two hose barbs on the bottom that attach directly to the hoses and that's it.

 

[slam]

The filter (screen assembly, really) came with the replacement reservoir (I sheared a hose barb during a battery replacement a few years ago). I'm the only mechanic on my car, it definitely wasn't added later.

Here's the filter, showing the crack:

Here's the flange it mounts on inside the reservoir body:

I couldn't find a replacement reservoir available in time, so I ziptied the base of the filter screen assembly and jammed it on the flange. It now fits nice and tight.

In other news I inspected the hoses and found no leaks, then pulled the hoses and inspected them and found no obstructions. I swapped the pump for a new one, refilled the fluid, and now have a perfectly functioning PS systems. It seems like the original pump was cavitating on its own.

It seems that foaming power steering fluid can be added to the list of symptoms of a pump failure.

One strange symptom of the old pump was the strength of the flow. If I removed the reservoir cap the foaming flow was so strong it was almost jetting out of the reservoir. It was like a geyser. With the new pump and all new fluid I can't see any flow in the reservoir. But the power steering feels stronger than ever.

Thanks folks for your help folks, the comments here pointed me towards a bad pump.

 

[Abacus]

Wow, I have never seen a replacement reservoir like that. Glad you got it fixed.