Hydraulic Fluid Used in System

[Kurtdeetz]

Hello
Was able to replace the leaky O rings pretty easy. Found out through the original paperwork that the hydraulic fluid to be used is a Mil Spec type they no longer make. Aero Shell 4 when I reserched was a compatible replacement. Any suggestion of what is best to use and where to get my hands on some? Loving this forum, some great info!

 

[Buckwheat]

I would think any hydraulic fluid would work

 

[Wandering Sagebrush]

Hello
Was able to replace the leaky O rings pretty easy. Found out through the original paperwork that the hydraulic fluid to be used is a Mil Spec type they no longer make. Aero Shell 4 when I reserched was a compatible replacement. Any suggestion of what is best to use and where to get my hands on some? Loving this forum, some great info!

Check with an aviation maintenance supply for a substitute. You should be able to find it on line.

Edit: there seems to be a lot of it... https://www.google.com/#q=shell+aeroshell+fluid+4

 

[Mike S.]

I was using power steering fluid but found it to thick in the cold weather so I switch to auto transmission fluid. It works fine, never gets hot enough to thin out also doesn't bypass the o-rings. Not my idea someone else told me about it but can't remember who. I have used it for 3-4 years everything seems OK.

 

[Toyman01]

I just bought a gallon of Phillips 66 X/C 5606A from here.

http://aviationoiloutlet.com/aviation-hydraulic-oil/Phillips-66-X-C-5606A-Aviation-Hydraulic-Fluid-1-gallon-bottle