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Steering Reservoir Tech (and Demo)

My recommendation with hose size is to always use the size that provides the appropriate flow velocity for the given flow rate. On a suction (feed) hose, the ideal number is 4 ft/sec so while I would not hesitate to use a -16 hose with -12 ends if the situation required, a CBR pump is likely no more than 3.5 to 4.5 GPM flow rate (unless you have one of the unregulated ones) and therefore a -12 feed hose is perfectly suitable, being 3.8 ft/sec at 4.5 GPM.
 
RadialDynamics said:
My recommendation with hose size is to always use the size that provides the appropriate flow velocity for the given flow rate. On a suction (feed) hose, the ideal number is 4 ft/sec so while I would not hesitate to use a -16 hose with -12 ends if the situation required, a CBR pump is likely no more than 3.5 to 4.5 GPM flow rate (unless you have one of the unregulated ones) and therefore a -12 feed hose is perfectly suitable, being 3.8 ft/sec at 4.5 GPM.
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I very much apreciate the info, thank you! I have no idea if my pump is unregulated or not, I just ordered through Loren, the SP33352 number off their website. But I am curious because I don't think I've run into issues on the stuff I've worked on before.

I helped John put your pump on Loren's Red Dot buggy, and I knew we went to -16 on it, so I wasnt sure if it would be helpful here. But I think we also had the 8gpm "cartridge" in it if I remember right.

Also got to see your reservoirs on the race trucks, nice stuff!

I under estimated the system on my buggy I guess. Working on Loren's stuff, I never ran into any issues that I was aware of, so I never put any real thought into it. Just hooked up lines and went. But of course when it gets personal and I'm working on my own stuff, things have to get a little more complicated 😂

Edit: I just searched it, and it looks like I should have the 1800 psi version, but I didn't see a flow rate on it. So now I'm wondering if mine IS the unregulated version? As I mentioned, I am pretty ignorant on this stuff, I just assumed that's what I needed.
 
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sp33352 is an internally flow regulated and pressure relieved pump, typically around 4 to 4.5 GPM max for the ones I have tested. No need to go bigger than -12. That pump you helped put on Loren's Red Dot is a significantly larger pump and yes, goes up to 8 GPM output, hence the need for the larger -16 feed hose.
 
RadialDynamics said:
sp33352 is an internally flow regulated and pressure relieved pump, typically around 4 to 4.5 GPM max for the ones I have tested. No need to go bigger than -12. That pump you helped put on Loren's Red Dot is a significantly larger pump and yes, goes up to 8 GPM output, hence the need for the larger -16 feed hose.
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Thanks again!

Just watched your video on flow vs. pressure. I'm trying to understand what's happening in my pump, based on your video, it's got me imagining my cavitation issue is actually related to the volume of fluid that's being bypassed internally in my pump, is that right? Theoretically, I probably have full flow long before I have a cavitation problem, and the problem results from the increased volume attempting to make it through the bypass to keep flow constant at higher RPM?

So do different fluids have any effect? I am running AC Delco(10-5073). It really seems like the problem is from pushing the limits of the internals of the pump, that a more effective way to bypass volume would be greatly beneficial.

 
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Bray D said:
I did exactly this a couple years ago. I still have cavitation issues with my setup at frigid temps, but that's a discussion for another thread (which already exists).
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Do you by chance have a link on the cold temperature and P/S fluid cavitation issues? I couldnt find it, have been wondering about that..
Thanks
 
not sure where else to put this so … share with the class whats going on

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The EV Tech thread would be the place for this one.

The basic rundown: this is a high voltage (200-800VDC) electrohydraulic pump system that I have been working on. I operate the pump on-demand by detecting steering inputs using a torque sensor pictured above. Otherwise, the pump runs constantly at a relatively low "standby" flow rate until steering demand is detected to conserve energy. I have two pump sizes available being a 2.5kW (3.3HP) that puts out 4 GPM and a 10kW (13HP) that puts out 8 GPM max.

It's still pre-production at the moment hence why I haven't shared much more than a few teasers on social but I have been working with a couple EV crawler builders over the last year as well as the Ultra4 EV spec and unlimited teams to get the first few vehicles in operation. If all goes according to plan, I will have two 2.5kW systems at KOH, one on the evolve racing s10 and another on the Hypercraft spec car.

The pump:
Radial Dynamics EV Steering Pump-1.JPG
 
Sorry to leave you all hanging while those on social media got the first peeks today. I just launched the next generation of the vortex reservoirs in which the vortex flow path design has remained unchanged, but the rest of the assembly has been redesigned for manufacturability and for fluid containment. The 3.5" size is available now and 4" size is about to start machining next week, due to be available in August.

Simple things first; the body is now fully machined including the ports. Even internally, there is not a single weld on or in this assembly. There is an auxiliary return port for plumbing hydroboost directly back to the res, the bottom cover is threaded into the body so that can be disassembled for easier cleaning (including access to the integrated magnet), and there is a 3.5" OD mounting clamp groove to help prevent slipping.

The biggest change, however, was the cap. I always liked radiator caps for their pressure relief and anti-vacuum functionality, plus they were cheap. The problem I ran into occasionally though was that if they relieved pressure while off-camber, they would puke oil and if the overflow hose was at all restricted, the next easiest exit path was under the upper cap gasket. I had a few customers that would end up with low oil levels and/or an oil coating on their reservoir exterior because of this and anything that releases oil from the system uncontrolled, I want to address.

I was inspired by the FATS system used for plumbing a fuel cell vent hose. Make the hose wrap around all sides of the cell so that the plumbing is always at a high point and you minimize the chance for liquid to escape the system. Steering reservoirs are easier in a way because they are generally tall, narrow cylinders. Anywhere between vertically upright to horizontal (90-degrees off-camber), the highest point in the reservoir will be somewhere along the perimeter of the reservoir top. The design I came up with was a larger diameter cap with internal flow channel around the perimeter which allows air to breath freely but traps liquid oil when off-camber. A check ball then takes care of tipping past 90-degrees, blocking off the vent port as a rollover valve.

With the cap being a larger diameter to cover more of the reservoir diameter, it made sense to match up the thread size of the PSC reservoirs and offer this cap by itself as a retrofit upgrade. The biggest complaint I have received about the PSC reservoirs and remote pressure valves is that when oil gets into the vent line, the remote pressure valve creates an oil mist when it relieves. This new cap will greatly reduce the mist and I am also working on my own compact remote pressure valve with further improvements but am not ready to release that just yet.

Link to the reservoir: Vortex Steering Reservoir, 3.5
Link to the reservoir cap: Gen II Vortex Reservoir Fluid Containment Cap (Also Fits PSC)

Any questions, ask away!
Radial Dynamics Gen II 3.5 Vortex Reservoir 10479 - 1.jpg
Radial Dynamics Gen II 3.5 Vortex Reservoir 10479 - 2.jpg

Radial Dynamics Fluid Containment Cap 10497-1.JPG
Radial Dynamics Fluid Containment Cap 10497-2.JPG

Radial Dynamics Fluid Containment Cap 10497-3.JPG
Radial Dynamics Fluid Containment Cap 10497-4.JPG
 
Theoretically, a remote radiator cap would do the trick. Any pressure relief valve (preferably with integrated anti-vacuum) on the end of the vent line will provide the necessary function. The design I am working to wrap up now is a remote, compact valve that performs the same pressure function as the radiator cap while, independently, the new reservoir cap serves the function of keeping oil in the reservoir. Regardless of whatever valve controls pressure, improving oil retention was something I felt was necessary to address.
 
RadialDynamics said:
The standard PSC cap vent port is drilled straight through the center so when off-camber (angle dependent on exact fill height), you submerge the vent port below fill level.
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I didn't see the pics inside yours when I had posted that. Totally makes sense now.

Will this help the little bit my vent is always weeping? It never really burps anymore but it's always wet around and just below it even though the remote vent valve is almost 3' away.
 
If you mean it is weeping at your cap, it sounds like either the o-ring is not sealing the top of the reservoir to the underside of the cap or the NPT push lock fitting is not sealed at the vent port. If it weeps at the remote vent valve, then that is what I intend for this new cap to address.
 
RadialDynamics said:
If you mean it is weeping at your cap, it sounds like either the o-ring is not sealing the top of the reservoir to the underside of the cap or the NPT push lock fitting is not sealed at the vent port. If it weeps at the remote vent valve, then that is what I intend for this new cap to address.
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No, not the reservoir. It weeps at the remote vent valve and is always a little wet under it. I'll let you know how it works out for me once I get a few days on it.
 
94toytruck said:
No, not the reservoir. It weeps at the remote vent valve and is always a little wet under it. I'll let you know how it works out for me once I get a few days on it.
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Thank you for the order!

mobil1syn said:
i am slightly disappointed in the npt on the cap.
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While normally I would share your sentiment and try to avoid NPT if at all possible for hydraulic plumbing, in the case of the vent port, it was the only logical option. We are talking a 10 PSI pneumatic vent port so using ORB/JIC fittings and braided plumbing is completely overkill. Plus, the fitting needs to swivel so that the cap can easily be removed without disconnecting the plumbing. Push lock tubing ends up being the most effective option, for which NPT push lock adapters are by far the most readily available fitting types. Therefore, I ultimately decided on 1/8" NPT for the vent port.
 
I like the design of the reservoir cap, but I’m not sure on the need for the push lock to remote vent? I replaced the push lock before ever running it and I’ve had 0 leaks or problems with this roll over valve/vent I made. Granted, it hasn’t been on it’s lid yet…
 

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DesertCJ said:
I like the design of the reservoir cap, but I’m not sure on the need for the push lock to remote vent? I replaced the push lock before ever running it and I’ve had 0 leaks or problems with this roll over valve/vent I made. Granted, it hasn’t been on it’s lid yet…
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As long as it has been working for you, there's no real harm in what you have setup there but assuming that the valve you have on that pipe nipple is strictly a check valve with a few PSI cracking pressure, then it will vent air as thermal expansion causes the oil fill level to rise. Once you shut the engine off and the oil cools back down to its original fill level, the reservoir will be under vacuum unless you have a way to let atmospheric air back in, which that valve alone will not do. It's not the end of the world but not ideal as the next time you start up, the pump will be more likely to cavitate until the oil warms up and reaches positive pressure again. This will affect larger displacement and higher flow pumps more noticeably than lower flow ones.

The other thing I notice about the valve setup you have done is that you have the sintered bronze filter facing up so in the desert, this is not a big deal but in wet environments with mud and rain, water can collect in the body of that filter/check valve. Venting action of that valve should only be in one direction so it shouldn't allow water to drip down into the reservoir but it's simply a risk.

My new remote breather/pressure valve that I will be sharing this week performs a more similar function to a radiator cap. It builds pressure in one direction, acting as a pressure relief, but as oil cools down it allows atmospheric air to flow back in so that the reservoir can only ever be between 0 and 10 PSI. With push lock fittings in and out, you can run the vent hose outlet to a safer location where, in the rare event of an oil discharge, it can be contained or at least discharged away from heat sources, and it will be less likely for water/dust ingress to occur.

Again, there isn't a definitive right or wrong answer and what has worked for you may not work ideally in every case. When I was redesigning this reservoir with a blank slate for cap/pressure control hardware, this new setup is what I concluded to be the simplest and most reliable solution to achieve my main objectives of: positive seal, oil trap, rollover valve, pressure relief, and anti-vacuum.
 
RadialDynamics said:
As long as it has been working for you, there's no real harm in what you have setup there but assuming that the valve you have on that pipe nipple is strictly a check valve with a few PSI cracking pressure, then it will vent air as thermal expansion causes the oil fill level to rise. Once you shut the engine off and the oil cools back down to its original fill level, the reservoir will be under vacuum unless you have a way to let atmospheric air back in, which that valve alone will not do. It's not the end of the world but not ideal as the next time you start up, the pump will be more likely to cavitate until the oil warms up and reaches positive pressure again. This will affect larger displacement and higher flow pumps more noticeably than lower flow ones.

The other thing I notice about the valve setup you have done is that you have the sintered bronze filter facing up so in the desert, this is not a big deal but in wet environments with mud and rain, water can collect in the body of that filter/check valve. Venting action of that valve should only be in one direction so it shouldn't allow water to drip down into the reservoir but it's simply a risk.

My new remote breather/pressure valve that I will be sharing this week performs a more similar function to a radiator cap. It builds pressure in one direction, acting as a pressure relief, but as oil cools down it allows atmospheric air to flow back in so that the reservoir can only ever be between 0 and 10 PSI. With push lock fittings in and out, you can run the vent hose outlet to a safer location where, in the rare event of an oil discharge, it can be contained or at least discharged away from heat sources, and it will be less likely for water/dust ingress to occur.

Again, there isn't a definitive right or wrong answer and what has worked for you may not work ideally in every case. When I was redesigning this reservoir with a blank slate for cap/pressure control hardware, this new setup is what I concluded to be the simplest and most reliable solution to achieve my main objectives of: positive seal, oil trap, rollover valve, pressure relief, and anti-vacuum.
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It’s not a psi check valve. Reservoir is always at atmospheric pressure. Just a male/male npt fitting with slots milled in one end and a coupler joining it with the sintered breather and a stainless ball inside the coupler to form a roll over valve. I have a hood and don’t drive into 4ft deep water but your deductive skills are on point! Keep coming up with cool stuff man…
 
Thanks! And yeah, since that is just a rollover valve, there is no positive pressure retention which really makes a difference in the higher flow pumps. If you ever do find that your pump whines at higher rpm, adding a pressure valve will help but otherwise, sounds like you have it under control.
 
I've got some catching up to do here. I'll start with a demo video of the fluid containment cap that I put together for Tech Tuesday two weeks ago:



I have been getting great feedback from customers about this cap. One said that after wheeling, his passenger floorboard was always coated in steering fluid but after installing this cap on his PSC reservoir and going out for another trip last weekend, his floor was completely dry afterwards. Another customer said that the new cap on his PSC reservoir "worked very well, still burped a little fluid on long steep climbs but nowhere near what it was with the PSC cap. The amount of fluid loss over a weekend seemed to be 1/8 of what it used to be".

Moving on to reservoir pressure valves, I recently launched my new 10 PSI Reservoir Breather Valve which uses thermal expansion of steering fluid to trap and pressurize air at the top of the reservoir to a maximum 10 PSI with an actual holding pressure of 6-7 PSI. A reverse flow check valve then allows atmospheric air to re-enter the reservoir as steering fluid cools and returns to a lower fill level in the reservoir, preventing a vacuum condition next time you start your engine. This compact valve is just a 1" OD x 1.5" long and includes 1/4" push lock tubing to connect to the Gen II Vortex Reservoir or PSC reservoir vent port.

Radial Dynamics 10 PSI Reservoir Beather Valve 10486-1.JPG
Radial Dynamics 10 PSI Reservoir Beather Valve 10486-3.JPG

Radial Dynamics 10 PSI Reservoir Beather Valve 10486-2.JPG


For last week's Tech Tuesday I did another demo video comparing this valve to other reservoir pressure valve hardware options. Whenever we talk about reservoir pressure valves or radiator caps to build pressure in a reservoir as a result of steering fluid thermal expansion, it is far too easy to grossly oversimplify what the pressure retaining/limiting capability of a valve really means. I admitedly realized through testing during the development phase of this valve that I, myself, have been just as guilty of blindly assuming a valve pressure rating means that the tank will end up containing such pressure.

Whether a reservoir uses a radiator cap or a remote pressure valve assembly to build pressure, the advertised pressure limit is not typically the actual continuous holding pressure you can expect to see in your reservoir. It is more commonly the max pressure you might see during the highest rate of air (or oil) flowing out of the tank during relief venting. Actual holding pressure is generally a good bit lower than the rated "max pressure" and some hardware options simply don't do close to what they advertise.

Valves are available now on the website at: Reservoir Breather Valve - 10 PSI

 
Following your product development has been super educational and helpful, thanks for sharing.

I’ve seen you compare against PSC and Howe, I’m curious have you ever looked at Lee? Any shortcomings or issues you’ve seen with their setups? Looks like just a radiator cap style, but I don’t know what’s inside the res

From what I’ve gathered from your stuff, if a guy was on a budget and could only splurge a little on one thing, I’m assuming you’d go with your reservoir?
Meaning, if you could only choose one, with all other components being good condition stock, would you go with your reservoir over even a single end ram for a trail rig?

Your comparison to heavy equipment with hydraulic circuits and the size of the reservoir on those that allows enough fluid time to get air out sells me on the importance of the reservoir in our applications. There’s just a brief second before the fluid returns to work, and I assume even a stock system that’s fed proper air free fluid will function surprisingly well without further modifications.
 
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