BigSqueeze

Additional fluid update: My last set of fluids was a standard 46w Hydraulic fluid and then Lube Guard Synthetic Power Steering Fluid which probably had some common additives like anti-wear and anti-foam. The steering feel was great. It felt responsive and light. I wasn't too keen about was the engine drag. At a standstill when turning the wheels left or right, the idle would surge as the power steering pump increased drag and the ecu would slightly overcompensate a reduction in idle speed. Otherwise the steering pump drag was unnoticeable. I switched from 46w hyd fluid to LubeGuard Universal Power Steering Fluid. It was close to what I expected. It didn't behave much differently than the 46w hydraulic. I've been wanting to try Pentosin CHF 202 or 11s. I've read Audi/Volvo forums complain about the fluid because it's a very thin fluid and rather expensive. I was curious about it because the viscosity index is incredible and is purely a hydraulic fluid. I found a place that had the 202 at a more reasonable price than I normally see and I bought a liter. I did the flush earlier today and things seem good. The CHF 202 is a thinner weight fluid so the power in the steering doesn't feel as aggressive. This also means the viscosity drag is less. When I turn the steering wheel at a standstill the engine speed doesn't dip then pop up to compensate for the pump drag. We'll see how it behaves the next couple of weeks. If the fluid behaves well in the system then I'd recommend it for more challenging climates. If I still lived in Iowa, this fluid would help out with winter weather cold starts.

Would the Megan Racing Radiator Subaru WRX & STi [2 Row] (2008-2014) MR-RT-SI08 radiator work for a 2012 Legacy 2.5i premium CVT? I think I need to add a CVT cooler which isn't a problem. I replaced the hoses and did a flush. Went to replace the thermostat and housing before refilling with coolant and I think the radiator is seeping. https://shop.redline360.com/products/megan-racing-radiator-subaru-wrx-sti-2-row-2008-2014-mr-rt-si08?variant=28753299669072&currency=USD&gclid=EAIaIQobChMI4MCZvfqJ6QIVIx-tBh1EvQ_UEAQYByABEgJ4jvD_BwE

Hey guys, I work in hydraulics making hose assemblies and such. I've been a little concerned about the sealing method on the metric to JIC (AN) adapter. Adding gasket compound to the metric side might work but I wouldn't rely on it alone. In my industry we use adapters often to lower the cost of replacing hose assemblies. The metric adapter going into the engine block is being used as a port adapter. A metric adapter and a BSPP (British Special Pipe Parallel) to JIC (Joint Industry Council) are similar in that the threads are on a parallel pipe, it will have a concave tip to seal on a pipe connection, and a recessed space between the threads and the hex base to seal on an o-ring or bonded washer. I would suggest adding a bonded washer to the metric side and doing or not doing the gasket material to the threads. Some adapters might have a bonded washer or flat o-ring built into the base of the adapter. An ideal adapter would be constructed of Aluminum and include a bonded washer. In my work, we carry adapter constructed of steel. I don't like the galvanic potential in a coolant system with an aluminum engine block and a high carbon steel adapter. I bet corrosion wouldn't take long to form. Metric port, British port, and O-ring Boss area all very similar in design. In fact a JIC male can be used as an O-ring Boss fitting if there's enough shoulder to support an o-ring or bonded washer because they share the same thread sizes. A JIC connection doesn't require a sealant as the cup and cones smash to seal. NPT or pipe thread fittings seal by deforming the threads, so does a BSPT (British Special Pipe Taper) connection. Thread tape is a lubricant allowing the tapered threads to mash easier. Instead of using a 45 degree hose fitting I would suggest trying a 45 degree female JIC to male JIC adapter and a straight fitting hose adapter or hose assembly. I would also like to see a hose tee with a JIC middle connection so either end could be capped if there is a leak. Hopefully that's also available constructed of aluminum. Looks like a difficult area to work. Crows feet help but they area pain themselves.

Swapping from one fluid to the next is fairly simple. I remove the return line going to the reservoir and put the end into a clear container like a gallon milk jug. I unmount the reservoir and support it so I can see it from the driver's seat and so it is the highest point in the system. Without turning on the car I raise the front of the car so the wheels are off the ground. I turn the steering wheel lock to lock. I watch the reservoir level and refill as needed. I stop doing this when the fluid exiting the return line into the clear container is consistently new fluid. Next step is to refill the reservoir and run the engine for about four seconds because the fluid from the reservoir is getting sucked in by the pump and exiting the return line. This is when I notice if the fluids are miscible. Sometimes the return line spits out froth. I refill the reservoir and repeat this about four or five times. When the fluid exiting looks consistently new fluid, I remount the reservoir and reattach the return line. Last step is to let the engine idle and let the fluid circulate. It helps to turn the steering lock to lock. After about five minutes, most of the air bubbles should have circulated. Then the front can be lowered to the ground. Check the fluid level before driving and add as needed. Drive around for a bit. Check the level again and add as needed. It's best to check the system when it is warm/hot and the car is level. The basic interaction between ATF and hydraulic fluid is the fluids foam. When switching between ATF fluids it takes about two quarts to adequately flush the system. When I switched to Hyd 46, I used about a gallon of fluid. What I've noticed is that each fluid has a different steering feel. The effort required to change direction and input to maintain a straight line are different with each fluid. Thus far I'd suggest Eneos Eco ATF Plus with the Lube Guard power steering protectant. This combination to me has improved the steering feel, reduced effort, and not adversely impacted miles per gallon.

I have replaced the fluid again. After using Eneos eco ATF in my girlfriends 2011 2.5i Legacy I would say that has been the easiest option. I work for a company that replaces hydraulic lines on construction equipment. I routinely have left over 46 weight hydraulic fluid from jobs and decided to try it out. At work we fill fluids like for like and the main considerations are if the tank lists zinc free, if the fluid is ATF (red), universal tractor fluid, or very rarely it might be motor oil. I haven't seen any equipment use brake fluid systems. I also have access to Aeroshell 46 which is a mineral base and highest quality fluid for aeronautical applications. It's similar to Pentosin CHF 202. Pentosin CHF 11s is lighter weight and fully synthetic so similar to Aeroshell 32, which I don't have on hand. I drained the Dex IV and flushed with 46w hydraulic fluid. I put about a gallon through the system before the fluid was clear. After driving a couple months with this fluid I wouldn't recommend the swap unless steering effort is major consideration. Compared to the Eneos Eco Atf, I'd say there isn't much difference in steering behavior and feel. Between the Dex IV and Hyd 46 I'd say the Hyd 46 reduces steering resistance and makes the feel much lighter. The Hyd 46 is probably a higher viscosity than Dex IV. The Hyd 46 will have the same anti-wear additives but none of the friction modifiers for clutch pacs to engage. Friction modifiers are an undesirable component for a hydraulic fluid but overall isn't going to make a big difference in fluid characteristics for the small power steering system. If it means having a fluid specifically for the small power steering system, it's not worth the space to keep a separate fluid. ATF is a fine fluid and most people might not notice and change from ATF to straight hydraulic fluid. I haven't noticed a difference in fuel economy between the Hyd 46 and Dex IV. It's been relatively cool in the bay area so I can't comment on hot weather performance. If you're inclined to try different fluids in the power steering system I'd recommend the Eneos Eco ATF plus. Next on my list is to try Pentosin CHF 202 when I go to replace the power steering lines. I haven't decided if I want to fabricate my own or just order replacements.

I’m really glad to see this thread. I’ve wanted to do this because I scrape the front or rear on my parking space curb, driveways, gutters, and regular roads in the San Francisco Bay Area. I’m a stock 2.5 with 215/60r16 tires so regular sedan. I’m only 5’10” and don’t enjoy entering or exiting the sedan height. I’d like to go full Outback suspension but OB springs and ‘13 regular struts might be my needs for increased ride height with better dampening and not have to completely change the suspension.

I replaced the Valvoline CVT fluid in the power steering system with Valvoline Dex VI synthetic. I noticed about a 2-5 mpg gain going to the Dex VI. Unfortunately there are too many things that could have influenced the specifics of the result but there was an undeniable increase in MPG after removing the CVT fluid from the power steering system. The product spec sheets do indicate viscosity at 100 C to be 7.2 for the CVT and 6.0 for the DexVI. Besides mpg, the fluid change did change the pump operating sound and steering feel to be slightly less responsive but with less drag. I recently changed my girlfriend's 2011 Subaru Legacy PS fluid with Eneos Eco ATF which is DexIII compatible and fully synthetic. Similar results with the steering feeling smoother and less drag but slightly less responsive. At this age with the vehicles the steering linkages could also have some slack so I don't think it's all to do solely with the fluid. I liked the CVT fluid characteristics the best. I couldn't hear the PS pump spooling and the steering felt more responsive, but it did negatively impact MPG. The DEX-VI fluid did flow much better while I was in Iowa when it hit zero degrees. Maybe there's a perfect fluid with the attributes of improving MPG and having a connected steering feeling. Someday I'll find it.

The groans have mostly disappeared except a little whine with initial startup of the day. The notched feeling going back and forth about 30 degrees from center is better but not gone. I'll give the dex iv fluid a shot if this cvt fluid has poor cold temp response. Thanks for the responses.

Great Legacy info in this forum and I might have a prose problem. I have a 2012 2.5i premium Legacy. I tried the Valvoline Maxlife synthetic in a red container but it might have damaged my pump. Has anyone else had this experience? Read on the a narrative of power steering flushes gone wrong. I recently did the cvt fluid drain and refill method twice with Valvoline cvt fluid. Going downhill I feel there is less resistance so I'm happy with the fluid. I had an extra quart of the fluid and flushed the power steering system. I read that several people use the valvoline maxlife atf red bottle as well as Mobil 1 synthetic atf. The reservoir cap and owner's manual suggest a dex fluid or idemitsu fluid. I figured the valvoline cvt is an idemitsu equivalent and gave it a shot. I pulled the return line to empty into a milk jug. I used a bottle pump to suck out the reservoir fluid. I removed the serpentine belt and jacked up the car. After the reservoir was filled with new valvoline cvt fluid, I spun the power steering pulley by hand. I kept the reservoir filled and it eventually changed color on the return end. Then I turned the steering wheel lock to lock while keeping the reservior full until I was almost out of fluid. Put the return line back on and everything was great. I drove the car about 200 miles and noticed the engine seemed quieter and the steering felt smooth. The steering before the flush always felt tough like well done steak. But I did wonder if I had done something wrong by using the cvt fluid. The old fluid was a reddish brown like old dex/mercon fluid. I thought I better use a dex fluid. I did the same procedure with the valvoline max life atf red bottle. I hand spun the power steering pulley, went lock to lock, and the fluid changed from amber to pink. I started the car and the power steering pump instantly started groaning. I let the fluid warm up while checking the reservoir level. The fluid seemed to be foamy like the groans were aspirating the dex fluid. This sound caused me to panic and the panic continued through six hundred feet of driving. I back out of my driveway and basically did a U turn back to the drive way. The steering was jittery and notched. The pump whinned and groaned even if it was just at idle. I drove to the nearest source of Valvoline CVT fluid and did a 1qt flush in the parking lot. Drove home and did another 1 qt flush. Returning to this fluid made major improvements in reducing the pump noises and notched feeling. It didn't eliminate them. After more thought I decided either the viscosity of the Maxlife atf dex/merc fluid was never good for the power steering fluid or the cvt fluid when mixed with maxlife had a chemical reaction and at this point I've damaged my pump. I thought about flushing with another quart of cvt but the system fluid had been amber after 30mi of driving. I was still getting a little groan at startup and whine when it was warm. I thought I'd use an atf supplament and see if there's a chemical fix. I initially wanted to try LubeGuard atf supplament platinum, frictiin modifier, or basic but the 12 ounce volume seemed excessive for a .8 quart system. I used the handpump to drain the reservoir and I added LubeGuard's power steering protectant. At first the pump groaned again like it was MaxLife in it again and I thought this was heading toward a breakdown. The noises went away and the notched feeling smoothed. The system seems better but not as good as the initial flush with cvt fluid.