Disable Power Steering?

David,
I don’t think so. Power steering and power assisted brake systems are not designed to operate without the assistance and will behave like an oxwagon if the power assisting pumps are not operational.
Find a clear empty space, like a huge parking lot and drive the car at about 10 mph. When safe, shut the engine down and try the steering and the brakes. It will be possible, but very hard to steer the car without the power assist and again possible, but very difficult to stop without the vacuum assist.
Regards
Chris

I doubt you can do that! On my SIII"E" with PS, I disconnected the output connection on the pump and modified the spring on the check valve to lower the pressure.The PS had less assist and that has suited me well.I did this 10 years ago so my memory is short on details. I also recall ( most probably very vaguely ) that a our resident guru at Coventry West once mentioned a change involving a torsion bar!! ( nothing to do with the suspension of course )

Chris is right. When a system is designed for power assist, it’s most likely going to be very heavy to operate w/o power assist. His suggestion to find out is spot on, just don’t extract the key from the steering lock. That can end bad - don’t ask :astonished:

On my S3 I wasn’t happy about the over assisted steering and considered various options to reduce or eliminate power assist. I ended up reducing the oil pressure in the system, thus reducing the amount of assist. The steering is still light, but much better and with more “feel”.

I have an article provided by a fellow forum member, Lloyd, that I can share if you’re interested.

Cheers … Ole

Beere sells a kit for the XJS (http://www.rob-beere-racing.co.uk/xjs-performance.html).

Probably just a variable orifice in the high pressure line, you could experiment with fixed orifices. At the end of the day you just force the pump to be in bypass (which shouldn’t hurt it).

I’m looking to do this on my Mk2 with PAS. Anyone that has successfully reduced the assist please provide details of how it was done. I assume reducing the spring pressure in the bypass valve would be one option (is spring cut down?). Orifices in high pressure line maybe another? Having it adjustable as in the Rob Beere’s kit would be nice…but not sure that kit fits Mk2 (or whether I need to spend over $200 to achieve this).

Tom

You might manage to do it without even having to make a new hose:

http://ph.parker.com/us/en/orifice-fittings-orifice-fitting-1

If you can get one of those with the right threads, and the right size orifice it will be a doddle - just fit that on the pressure output of the pump.

I’m not sure I even remember that article, written by an, ummm, friend… In a few words, what did it say, ummm, I’m asking for a, errr, friend…
LLo… ummm, Schmedley, Joe Schmedley

I have the sII PS, and I would never think of disabling it. Why?? It is a very nice assist, doesn’t take much power to drive and does not deter from the handling. If you need to replace the front seal, be sure to get the high pressure seal, not the standard. Also, there is room there to put two seals into the pump, one in front of the other. I took the two pressure hoses to a hydraulic shop and had them duplicated for not so many bucks. The no-pressure reservoir hose is just a piece of cheap heater hose.
LLoyd

I’d love to see an article as mentioned above.

I did send an email to Rob Beere Racing to see if they have anything for the E-Type.

As for why, clearly everything is subjective. I am still waiting for delivery of my car, but the PS car I drive was very floaty. I’d like to tighten it up a bit. Obviously, I need to see how my car handles first but I am interested in knowing options.

Thanks all!

What do you mean by “floaty”? Like the tie rod ends are bad and the car wanders back and forth??
LLoyd

my 69 has power steering, and I have driven it without it connected, and its nowhere near the way old American cars were when you disconnected it. It was no harder to turn or steer than an E-type with no power steering. ( I have driven both) is it good for the rack? I dont know.probably not. that would be my concern. and the car shouldnt be floaty at all. something else is wrong.

if you want manual steering, buy a standard rack, they are easy to come by, but if you are going to ditch the power steering I will pay for shipping of the old parts to my house… ( they are hard to find and very expensive!!!)

I mean really light steering control ie it was too effortless to change lanes.

-dsd

Thanks, Andrew. That might just be a viable option. Need to look into thread sizes.

Many cars that go to PS change the ratio so steering is quicker and the PS makes up the increased effort, thus the reason most steer very hard when the PS is inoperable. I tried, but could not determine if Jaguar changed the ratio when the optioned PS. From what Bob said, it sounds as if the ratio was not changed. IMO, I would not use an orifice to restrict the flow, as that would probably make it run against bypass, increasing fuel usage and heating up the components. Also, IMO, to simply decrease the pressure would simply decrease the power assist when you would want it the most, when effort need is highest. I would think the best way to decrease power assist would be to change the spring/torsion that opens the hydraulic valve, and this may not be easy to re-engineer. But in the end, the best way to disable PS is as Bob said, change the rack to a manual rack. Of course, what ever works for you is fine.
Tom

I cant say if they did or not, but having access to a couple 69’s that were built a week apart, they sure seem similar, the PS is nice to be able to spin the wheel in a parking lot with one finger in the steering wheel. but once rolling they feel the same.

And if my VIN didnt begin with a P (to indicate power steering) I would switch to a manual rack.
Only because I like the simplicity, no pumps, potential leaky fluids etc. and I think it goes back to the basics of 60’s era sports cars. but as long as I have a working PS system I will keep it original !!

can you even buy modern cars with manual steering anymore?

You might take a look at this electric power steering conversion kit.http://www.ezpowersteering.nl/type/161/74/Jaguar_E-Type_Series_1.html

Yes, I believe that is correct.
Check the archives and search for Dick Maury’s posts on the subject.

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I’ll send it to you … Ole

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found it.

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Thanks all. Really gave me a lot to read up on.