KRC power steering with hydroboost - how much fluid needed to fill?

[dbo_texas]

Did a quick search but didn't see any threads describing this. I've got a Coyote setup with KRC power steering pump/reservoir married to a Forte hydroboost setup. Can anyone who has used this combination tell me how much fluid is needed to fill the system for the first time? I'm planning to buy 2 quarts but wasn't sure if that was enough, and I'm going to use the KRC PS fluid so it isn't something you can just pick up at the auto parts store. I might add an oil cooler to the lower opening ( below the radiator) and run the PS fluid through that....maybe not required but I like the look of the cooler down there so might as well use it.

Also, for those with a similar setup, I was wondering about your hose lengths and connections. Do you have any measurements of how long your PS hoses need to be from the PS pump over to the hydroboost, and from the hydroboost to the steering rack? Bonus points if you also have pictures showing how you routed your lines.

[Lidodrip]

Hello Darryl,

I have a Coyote with a KRC power steering pump and Forte Hydroboost. I also have a power steering cooler (Mishimoto 10 row oil cooler) mounted in the lower cowl opening. While I don't remember exactly how much PS fluid I used, I am pretty sure that 2 quarts would be more than enough. The reservoir is quite small on the KRC pump. I used stainless steel braided PTFE tubing with AN fittings to make all the connections. After 2000 miles, no leaks or issues. I made all the lines myself, but I never bothered to measure their length - just cut to fit. For the high pressure lines I used 6AN fittings and ordered 16' of hose. For the low pressure returns, I had a 6AN hose from the hydroboost and a 6AN hose from the power steering rack come together with a dual 6AN Y-connector with a single 10AN outlet. I then used a 10AN line (ordered 10') to the power steering cooler and a 10AN line back to the KRC pump. I had more than enough hose to make all the connections for both the high and low pressure circuits.

Here is the plumbing from the hydroboost (the Y connector is the black fitting next to the "Return to Cooler"):


The return from the cooler to the KRC pump:


Power steering cooler plumbed into the lower cowl space:


Power steering cooler from the inside:


Hope this helps,
James

[dbo_texas]

Thanks James - this is a huge help.

[Lidodrip]

I did find a post where someone said they used about 3/4 of a quart to fully fill their power steering system.

James

[dbo_texas]

I did find a post where someone said they used about 3/4 of a quart to fully fill their power steering system.

James

Thanks - yeah I knew the KRC power steering setup didn't use a whole lot, I just wasn't sure with adding the hydroboost if it adds any significant amount of volume (extra hose lengths, plus the chamber in the hydroboost, etc). I'll go ahead and get 2 quarts.

Were there any special steps to bleed/burp the system after setting it up? There aren't really any instructions that I've found, other than a couple of YouTube videos.....turn on engine, turn steering wheel lock-to-lock a few times, shut down, check reservoir level, add fluid, repeat, etc.

[Lidodrip]

Were there any special steps to bleed/burp the system after setting it up? There aren't really any instructions that I've found, other than a couple of YouTube videos.....turn on engine, turn steering wheel lock-to-lock a few times, shut down, check reservoir level, add fluid, repeat, etc.

That is pretty much what I did. First few times, I only ran the engine for less than 30 seconds without doing any turns. After that, a few lock to lock turns and I was done. I don't know if this makes a difference, but I did my lock to lock turns with the wheels on the ground so there was the normal resistance. Overall, pretty easy process.

James

[dbo_texas]

hey James - I'm getting ready to start buying the high pressure PTFE braided lines and AN fittings, but have thoroughly confused myself in terms of which AN sizes I need for both hoses & fittings and wanted to confirm a couple of things.

1. Does your setup pretty much follow this diagram but with the oil cooler in-line before the combined returns go back to the PS reservoir?
2. Do you happen to know the AN fitting size of the return line from the FFR power steering rack? My kit is from 2019 and ordered FFR p/n 16473 Coyote PS Kit so not sure what size fittings come on that rack. You mentioned using 6AN lines to your Y-adapter, but this diagram indicates 8AN lines on the rack low pressure side. Just wondering which size is correct as it will impact which Y-adapter I get.
3. I see the Mishimoto oil cooler has 10AN connections so that aligns w/ your 10AN line going from the Y-adapter to the oil cooler inlet. From the oil cooler to KRC PS reservoir, do you happen to know the size of the adapter needed on KRC reservoir? Is that also 10AN or did you have to convert from 10AN to something else?