You shouldn't leave the Auto-Rx in so long!

[ALS]

I added an ounce of auto-Rx in my PS reservoir and figured on flushing it a few months later. Well I forgot about the PS system and drove another 5,000 miles with no problems. Well it got cold here in Pittsburgh over the last few days and the PS pump started making a growling noise. Well today I removed the cap on the reservoir and was surprised by the POP sound from the air pressure build up. Looking inside the reservoir I saw lots of foam. I pulled out a baster and removed all the PS fluid in the reservoir and replaced the fluid with new. Growling is now gone and I will note that there was some pretty nasty stuff floating in the reservoir. I'm going to get my mechanic to flush the system tonight. My advice is not to leave your Auto-Rx in more than the recommended time/distance.

 

[bmwtechguy]

I would add that in a neglected P/S system, that if you use any type of cleaner such as Auto-Rx or LC it would not be a bad idea to install an inline Magnefine type filter in the p/s reservoir return hose. This is the low pressure hose that returns the fluid to the reservoir. Otherwise, what happens to all that crud that gets loosened up by the cleaner? I'd rather not have it floating around, waiting to get stuck in a valve in the steering gear.

 

[ALS]

Well I figured out why what was happening was happening. From what I can tell the Auto-Rx was thickening up in the PS fluid as the temperature was getting colder. Once I exchanged the PS fluid out the problem was corrected. I guess it would be prudent if you live in a colder climate not to Auto-Rx your PS system in the winter.