Correct fluid for power steering conversion
 

I'm in the process of converting to electric power steering using the Volvo pump. Is there a right or wrong fluid to use? Mazda calls for ATF type F, but that's not necessarily what the Volvo pump needs. Does anyone have experience with this that they can share?

All Dexron ATFs are backwards compatible with Type F.

I would find the specified fluid for the Volvo that the pump came out of (V50, I think?) and if it specifies Dexron then just use that.

The volvo pump is a TRW pump like the opel astra pump I believe. That requires European cars synthetic fluid(LDAS , chF11s). Otherwise it overheats and takes out the pump using the dexron fluid. So take your pick...take out the pump with dexron or possibly the seals on the rack if they aren't compatible with the synthetic fluid. I'm doing the same thing but with an opel pump. I plan on using the synthetic since pumps are hard to come by in North america.

It's surprising how little information there is online about this, lol. From what I've deduced, it looks like I need CHF11S.

Now, question now becomes:
Will this mess with the seals on the rack?

Sorry...can't help you there. But yes had a hard time digging any info on the pump other then basically connect two of the three control wires together with 12volts and it works. The volvo pump like the later astra pumps has CAN wires so it has an input for vss unlike the earlier pumps. They all are known for slower reaction with very quick and large left to right wheel movement such as drifting or tight autocross turns. For the street it's fine and with a left hand rack the high pressure line is very short if you place the pump on the driver side. A slick place to mount it is under the driver fender where the headlight washer pump/tank sat on some turbo models and use the hole for the integrated fill tank(if you don't have front mount intercooler piping or full size battery that normally comes up/resides in that spot) .It's stealthy and pretty darn slick courtesy of our Australian friends that I seen mount them there.

Did a little bit more digging on the power steering fluid question. Whether the posts I can across on the net are BS that is another question. CHF 11s is an aviation based hydraulic fluid. It is made for extreme temp. variances and is a thinner oil but still has a high viscosity. So the issues of electric pump overheats/failures with atf fluids such as dexron may be to somewhat due to that. The CHF manufacturers / car companies say not to mix the two so you would need to flush out the rack completely. From what I gather all new ATF fluids are synthetic now anyways and not petroleum based as the past. Question stands whether the chf 11s based synthetic will attack the rack seals. What I think I will be using is Valvoline VPS prof. series power steering fluid. Looking at the specs. Valvoline says it's compatible with domestic /Asian and European cars. They also state in their literature is the fluid is compatible with chf 11s systems.
Valvoline literature
US_Val_VPSSyn_PSF_EN.pdf - DocuSign CLM (springcm.com)

you might think about ditching the Volvo pump and using the 2004-2009 Mazda 3 pump. same deal its an electrically operated hydraulic pump.
it uses Dexron 3, which is the same as the FC

Appreciate the feedback here.

I guess my follow up question is how bad ATF type F would be for the Volvo pump?

I get that Volvo reccommends the fluid based on how hot the pump will get. But, if i ran a power steering cooler in line with the return, with a dedicated fan, would this keep the fluid cool enough to extend the life of the pump?

In my eyes, it's a lot easier to replace the pump than the rack, so would like to avoid any risks when it comes to possible seal failure.

Does the mazda 3 pump require a separate controller or ecu control for speed and other inputs?

Try it and find out. Info is scarce on that searching the net. Personally that Valvoline universal synthetic oil looks like the best solution/compromise.

You're right. That does seem like a viable option. The best of both worlds it seems (or the best of a shitty situation. Glass half empty).

You mentioned draining the rack completely. Is there an easy way to do this without either getting fluid everywhere, or removing the rack from the car?

Just leave the return line off the electric pump and into a container(cycle the rack full left / right first ) which will expel most of it then run the pump with new fluid until all of the rack fluid looks gone with full left to right rack cycling .Should be pretty simple. I plan on doing this in the next couple days.

it does have a CAN thing, probably the same as the Volvo, the Mazda 3 and V40 are cousins. basically the advantage to the Mazda stuff is that we can get info about it
https://cimg0.ibsrv.net/gimg/www.rx7...b90ed22273.jpg

This seems like a good option as well. Granted the wiring seems a bit more than the Volvo pump, it looks like a lot of the stuff can be omitted (steering angle, CAN). Wonder how the size of the pump compares to the Volvo unit
And, since this takes Dexron 3, the aforementioned Valvoline fluid should be compatible as well, which is a plus.

it must be close to the same size

https://cimg4.ibsrv.net/gimg/www.rx7...a5958e0e62.jpg

Yes looks very similar to the volvo pump.The EHPAS controller is part of the pump I take it?

Got it, that makes sense.

May I ask what your reason is for flushing it? Switching to a different pump or fluid?

you happen to have any pictures of one installed in this location? Just got a V50 pump, and I'm scratching my head on where to mount it as it's quite a bit bigger than i was thinking it would be.

It's not the volvo pump but close.The reservoir may be slightly shorter then the volvo one. It's mounted in 3 spots and is very secure/rigid. I made the mounting bracket to use the unit's rubber mounting pads to dampan vibration but Ive seen them hard mounted by Australians in that spot .The thin stainless heat shield and blocked brake duct is there to deflect the oil cooler heat. I also plan on a cold air hose in addition. The return line comes off of a small universal cooler. The nice thing about this pump is the reservoir can be rotated to place the return pip where needed since it has a worm gear clamp.I did have to dome the sheet metal and headlight washer hole to fit it nicely.The fill is very accesible and best it's mainly hidden.
https://cimg5.ibsrv.net/gimg/www.rx7...3d3da3034f.jpg
https://cimg0.ibsrv.net/gimg/www.rx7...4106f983b4.jpg
https://cimg6.ibsrv.net/gimg/www.rx7...2e1e21cbd4.jpg

That's nice and clean. What's the pump off? Doesn't look like the mazda3 pump either.

It's an earlier opel/vauxhall/holden astra pump.These are hard to come by in north america since they where on right hand drive cars.It came out decent but it was a bit of work /time to fit and mount it and make brake duct work to use the fender liner.

I just picked this pump up from the junkyard. Going to see if it works without CAN communication. While I was there, I noticed the later year Mazda 3s seem to have an almost identical pump, but has the same number of wired connections as the Volvo pump and slightly revised bracketry. It's otherwise visually identical. Was there a reason for not suggesting this one? I.e. doesnt work without CAN communication or something? I'm going back eventually for alternators so if this is also a valid solution, I can pick one up. The pictures I included are from a 2012 car

https://cimg8.ibsrv.net/gimg/www.rx7...7a9b78787f.jpg
https://cimg0.ibsrv.net/gimg/www.rx7...7bf9ad04d8.jpg

https://cimg7.ibsrv.net/gimg/www.rx7...8167d0df0a.jpg

Also yes, the Mazda pump is very comparably sized to the Volvo unit

totally forgot! there are a a bunch of different ones actually now that i look. 2004-2013 Mazda 3, and 2006-2017 Mazda 5.

the 2010-2011 pump is one number and the 2012-2013 is another part number. after 2013 Ford is gone, and Mazda goes with fully electric PS

which reminds me i saw this for sale, if you type in the number on that box into teh internets, it works. i'm not sure what is bolt on and what is fabrication, but its neat
https://cimg4.ibsrv.net/gimg/www.rx7...e1563e36b4.jpg
https://cimg6.ibsrv.net/gimg/www.rx7...e56d315913.jpg
https://cimg8.ibsrv.net/gimg/www.rx7...fc641454d8.jpg

This is pretty neat. If fully electric, it would negate the dilemma of where to mount a pump. Wonder what car this is out of, and how much work it'd be to install and get working?

part number is Suzuki Alto/Mazda Carol

the Mazda number for that box is 1A0267880B