I installed a low-mileage used power steering pump but have been having issues. I believe the lines are bled of air (I followed bleeding procedures and used a vacuum pump), I don't believe there are leaks that could allow air in, but I am getting intermittent performance as follows:

• power steering will work perfectly until I decelerate, and then it "drops out" and the steering becomes very heavy
• once heavy, it will stay that way for awhile, then bringing up revs again will "break" the steering free and it will work properly again until I decelerate, and it "drops out" again

I used Sea Foam trans tune on it and the lower viscosity cleaning fluid seem to temporarily help but the symptoms immediately returned as before once the flush was complete.

I suspect I just got unlucky and replaced an old, working pump with a newer, non-working pump. If anyone has any thoughts or has experienced similar results please let me know. Before the pump swap the steering worked perfectly.
- scooter

 

There's really not a bleeding procedure like you need with brakes. With power steering, simply raise the front end to get the wheels off the ground and with the engine running, steer to the limit each direction several times. The fluid constantly circulates in power steering, there's no "dead end" lines like you have with brakes. Make sure the fluid stays full in the pump reservoir, and that no bubbles keep coming out of that fluid. There will be bubbles initially, but they should disappear.

I don't know enough about the Jaguar system to know how much electronic control there is of the hydraulic boost, but I know it's variable. I had an incident one time where my cruise control wouldn't engage. When that happens, I simply shut off and restart and it's fine. I was on the highway, and instead of pulling to the shoulder and stopping, I simply shifted to neutral, shut the motor off and immediately cranked it back up. Cruise engaged, but steering was slightly heavy. Not unassisted heavy, but heavier than usual. Starting the car at 50+ miles per hour threw something off in the electronics for the boost. When I got a chance, I did pull off, stop, shut down the engine and restarted, and everything was normal again. My point is that there is some electronic control of steering pressure, but I don't know how that works, so you might not actually have a pump problem but an electronics problem. I can't really help you with T/S the symptoms you had, I just wanted to reassure you that bleeding the system is no big deal.

 

Thanks, I concluded that it had to be a pump issue versus a variable control issue based on the fact that when it drops out, it's completely gone, no assist whatsoever, at any speed. I have a new pump (remanufactured, I can't spend $800 on a new pump) so we'll see what happens with the swap. I should have left my 142k mile pump alone, it was fine. Oh well.

 

Can you check the car with SDD? The variable assist might have set a code that would help?
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Sadly I don't have SDD (I do miss all the open source tooling available in the Subaru world), but I finished swapping out the pump and it was definitely the pump... the new pump works great, no noise and no inconsistent performance. What made me suspect the pump most was when I had the low viscosity cleaner in the reservoir it felt better, and upon going back to Pentosin ATF 1 (much thicker than the cleaner) the pump performance returned to poor. I took notes and some pictures and will post a 'how to' writeup under a new thread.

 

I replaced the fluid in mine with Dextron II. ATF1 is different. I think thinner. How does the pump sound now? Mine growls a little on startup. Maybe ATF 1 will be quieter.

 

Am not sure re: viscosities, I haven't used anything other than the Pentosin.