GRM expertise needed: What is the true proper method to de-power a hydraulic steering rack?

Since I have come to to trust GRM as the world brain trust for, well, everything, here is the sitrep:

The Escort's power steering pump recently started whining faintly (actually sounds more like a centrifugal blower!). I presume that at some point it will fail entirely. Conveniently enough, de-powering the rack is on my list of race car mods anyway. So, the correct, as in having the least amount of resistance/sticktion left in the rack, way to do this is?

https://www.flyinmiata.com/tech/depower.php

Hope this helps!

Just draining the fluid and looping the lines works quite well, you'll only get a minor decrease in resistance by removing the internal seals. I'd recommend trying looped lines first to see if you want less resistance before you go through all the work of removing the seals.

The easiest way is to loop the lines. But then you are still pushing fluid back and forth, which can cause a lot of resistance.

The proper way is to take apart the rack, remove the seals, and plug up all the holes. Here's a good how-to about halfway down the page. SC300 de-power steering

I used the FM method on my race RX7s rack. Works great.

I'd loop the lines and test it that way first, mostly so you can confirm that no power steering is an acceptable solution. If it's good like that or only slightly too heavy, go ahead and remove the seals.

By doing the looped lines test first, that'll confirm that you're not in a situation where the steering ends up too heavy without PS and you can't move the wheel fast enough. Depending on steering ratio, amount of caster, size / stickiness of tires, etc. that can be a problem on some cars.

FWD cars in general often don't do well without power steering...you're moving powered wheels with resistance-adding axles attached to them on a front-heavy car.

Not sure about that one in particular, but the torsion spring that takes care of the valve actuation on some racks isn't quite up to the duty of extended unpowered driving, and if there are rag joints in the column, those may also need to be addressed. All that extra force you apply at the wheel also exists in the column, which may not have been designed for it.

I have a de-powered E30 that has been fantastic, and I've never seen owners report rack issues, but I've heard about some failures on various GM products that were de-powered and eventually failed either in the assist valving or at the rag joints.

In reply to gearheadE30:

2nd gen Escorts had a manual rack as factory option and the column hardware is the same as for the powered rack, and is the same column used in the 3rd gen Escort and ZX2. It seems that standard practice then, is drain the lines and loop them. And to not bother trying to turn the wheel at a dead stop with wide sticky tires.

Thanks guys!

WildScotsRacing wrote: It seems that standard practice then, is drain the lines and loop them.

Standard practice maybe...But for the "true proper" and "correct" method, click here.

Driven5 wrote:

WildScotsRacing wrote: It seems that standard practice then, is drain the lines and loop them.

Standard practice maybe...But for the "true proper" and "correct" method, click here.

Oooohhh, a GRM project. I see myself acquiring a salvage yard rack, soon Thanks for that link. Should drive quite nicely when it's finished, in addition the slight weight loss and power gain!

Alright guys, I need a final opinion on this project. The spool valve splines; does anyone here feel that packing the splines with JB Weld will have enough strength to hold up? Or is that asking for trouble eventually, and I should I just weld them properly?

Bump for my question above. Anyone?

JB Weld sounds like a good way to get foreign object debris in the moving bits of the rack to me.

Stupid question I know, but can someone offer a comparison between driving the car with the belt off but the system intact, and looping the lines? I've driven the RX-7 in the former condition, but it is a pain at low speeds. Is it much easier with the lines looped?

WildScotsRacing wrote: Alright guys, I need a final opinion on this project. The spool valve splines; does anyone here feel that packing the splines with JB Weld will have enough strength to hold up? Or is that asking for trouble eventually, and I should I just weld them properly?

I did a de-power on my miata in the last couple months and I don't thing JB weld will work in the long run. It was literally 5 minutes of tig welding including prep. I would just take it to a welding shop if you don't have the means at home.

Here is my finished product:

In reply to NordicSaab:

As I suspected. Thanks for not letting me ignore my instinct to weld it up properly

1988RedT2 wrote: Stupid question I know, but can someone offer a comparison between driving the car with the belt off but the system intact, and looping the lines? I've driven the RX-7 in the former condition, but it is a pain at low speeds. Is it much easier with the lines looped?

Think pushing a dead motorcycle in gear vs the same in neutral.

Properly applied (degrease thrice, pour some in the hole, push the shaft in until excess epoxy stops coming out) a good epoxy would probably work in the splines. Consider that the compression strength of west 105/205 is 11,400 psi. I have a feeling you aren't getting anywhere near enough force on the spline contact faces to move that, and that's before taking into account any bonding that will happen.

I've been wanting to depower the rack in the Fairmont for years. The power steering system is over boosted and finicky. I need to find a water pump pulley that will run the alternator and the water pump instead of the power steering pump and water pump.