After replacing the carb and power steering pump I'm starting to drive this new to me '66 farther than just around the neighborhood. I took it for a 40 minute drive around town and towards the end I could hear the power steering pump whining/cavitating. Got back home and removed the cap and the fluid in the reservoir was full of tiny bubbles. Not foamy, but lots of bubbles. It's currently filled with Dexron VI since that's what the internet tells me is compatible with the Type A that it calls for. The pump is new, and according to the prior owner service records the steering box is also relatively new. I added a filter in the return line when replacing the pump, and just checked it to see if it might be plugged, but it looks fine. I checked the archives and see strongly held opinions on ATF vs. PS fluid... Thought I'd check in to see if anyone else has experienced this with modern ATF before I try switching to PS fluid.

cheers,
--steve

 

I've not had any issues using dexron in the power steering circuit. I"ve been running dexron for years.

I do believe you still have air in the system or you have a bad new pump. Your issue might be with the flow control valve in the pump. There are many different ones. A lot of remanufactured pumps aren't really" one size fits all" in the flow valve applications.

It might help if you tell us what bleeding procedure method did you use and perhaps pump supplier/rebuilder.

I changed steering boxes four years ago, and was quite surprised at how many rounds of bleeding I had to pursue before the foaming stopped.

 

Thanks for the reply. The pump is a new Lares unit, from Rock Auto. I ordered it according to year/make/model. For the steering box, I don't know, the receipt doesn't mention a brand. To bleed it I turned the wheel lock to lock a few times, then started the engine and did the same. It was fine idling and for the first 30 minutes or so of driving, it was just on the way home that I started hearing it. Glad to hear that it might just need more bleeding though, I can do that and give it time before trying something else.

--steve

 

With the front wheels hanging, the reservoir cap off and the reservoir full, slowly turn the steering wheel lock-to-lock until the air is removed.

 

There is still air in the system, which is why you are hearing groaning and seeing foam. Keep bleeding it. You may also need to top off after the bubbles pop. I use Dex III in mine. Dex IV is SUPPOSED to be backwards compatible but has friction modifiers that Dex III does not.