Can't figure why WRV started using Valvoline Engine oil for the hydraulic pump?

[kraig]

Valvoline premium blue 15-40 is a great oil for the engine, but it is not the right oil for my hydraulic system. When I look in my 2006 WRV owners manual, it does say to use say to use Valvoline Premium Blue motor oil in the hydraulic resvoir. For over 40 years I have had constuction equipment and I never used a detergent motor oil in anything, nor did ever see it recommended in writing. I have used NON detergent motor oil ok and different hydraulic oils.

Here is what I learned a long time ago. You never want to use a detergent oil in a hydraulic system, it can cause foaming in the oil, which will cavitation in the hydraulic pump and result in premature pump failure. Secondly, it could deposit the contaminants as sludge throughout the hydraulic system.

Reading different posts on the forum, it appears there have been pump problems, hydaulic fan motors, and brake stopping problems. The reason I writing this is yesterday, I did talk to a Meritor Tech support person about using the Valvoline motor oil and he said it is not the right oil to be using for your brakes.

I know WRV did use Dextron on the earlier coaches and I never had a problem in 10 years on my 2000. When I got my 2007, it had cooler failure, and dealer replaced the Valvoline with Dextron and everything worked fine. I did change my fluid to the Chevron Rando HDZ ISO 46. What I read on the forum, some of you use Rando and some are using the 15-40. The problem with the Rando is getting it. None of the Chevron distributors stocked it, so they ordered it from the factory. In my opinion if you don't want to use or can't get the Chevron, you could use most any other hydraulic oil or dextron. You probably should flush out the 15-40 first. I would think for sure the brakes would work better.

I know oils have made a lot changes over the years, but the Premium is still a detergent oil. The pumps would still foam up the detergent oil. I wouldn't use it in my hydraulic system. Maybe somebody could tell me why WRV thought this was the right oil to use.

This just my opinion and I am sure there will be other comments!

[Papa_Jim]

I'm throwing my hat into this ring, because although I'm running a different brand of coach, I've been asking the same questions.

Monaco had a problem using the red Dexron oil. Some people experienced loss of steering when things got really hot. Then they switched to a heavier grade hydraulic oil, and some people had trouble with poor steering and blowing out seals and oil lines in cooler temperatures. Then they switched to a 15W40 motor oil, and haven't had any trouble ever since. I understand that to this day, Monaco coaches use 15W40 oil in the hydraulic systems.

My coach has the red Dexron oil in the hydraulic system. A couple of years ago, I drove down into the southern states, and on a really hot day in city traffic, I lost my power steering. I managed to pull over and let things cool down for a while, then the steering returned.

When I got home, I drained the hydraulic system, changed the filters, and talked to my oil supplier about a multi-grade hydraulic oil to replace the red Dexron oil. He couldn't find anything, and finally suggested that I consider using a multi-viscosity engine oil. His reasoning was that there is nothing more precise than a hydraulic valve lifter, and it is lubricated using the multi-viscosity engine oil.

I couldn't make up my mind,and I put in a fresh batch of the red Dexron oil. But the next time my steering fails in really hot weather, I may wonder if my decision was the right one.