Thought i would post the fix as its always frustrating when people don't

So to recap, intermittent heavy steering , especially at low speeds, turned out it was directly related to engine speed, so do not be fooled into thinking it has anything to do with road speed as engine is dropping to idle when turning and at junctions etc.

You can test this by sitting in the car with it in park , taking up the slack in the steering , giving it 3000 rpm with your finger on the wheel , if the wheel moves and then returns when you go back to idle you have the same issue as i had.

Pump i hear you all cry , pump was pressure tested and giving 1300 Lbs of pressure at 750 RMP , so it was not the pump, but to be on the safe side pump was removed and rebuilt, on rebuilding the pump rubber particles were noticed on the pressure valve piston must be a hose somewhere breaking down, now to be on the safe side you can argue if one hose in the system is breaking down then there is a chance they are all at the same level of about to be knackered, so a bit like changing a bulb in a multi bulb fitting i had them all changed to save chasing the issue, now steering is fine, so the issue was flow and not pressure due to a hose collapsing under vacuum and the extremely patient and value for money people who did this all for me. Steering Specialists in Wakefield 01924 26799 James Kenyon is the man to talk to , he especially likes changing serpentine belts !

Last edited by gavinn on 21st Feb 2019 9:52am. Edited 1 time in total

Well done !
I've still been too lazy to progress with mine.

You're findings are interesting I vaguely remember another LR model where it was often recommended to change or clean the PAS reservoir in order to get rid of accumulated rubber debris in the filter that impeded flow.. There was no explanation I remember about which part(s) the rubber came from.
Anyway, it's great we've got another route to check for this seemingly more frequent problem. Paul,
2001 Discovery 2 TD5, 211,000 miles & climbing
2006 FFRR TDV8 Vogue 151,000 miles & now sold
Member of Midland (Land) Rover Owners Club, www.mroc.co.uk

Brilliant- thank you for the update on the fix!

Gavin,
finally moved forwards with our TDv8 with similar symptoms.
Using your test of holding some steering lock on while raising the engine speed from idle generates interesting results & possibly identifies a similar cause of my problems.
With the engine cold, revving the engine has no impact on the steering angle, but with a warm engine / warmer power steering fluid , the steering wheel moves significantly. I think this leads to the same conclusion as you : I'm not getting full pressure / flow at idle when the engine /fluid is warm.
Unlike you I haven't yet confirmed the pump output is OK / changed the pump - so it's still a possible cause in addition to degraded hoses / pipes.
I'm now going to assess all the pipes to decide if there's anything obvious causing a restriction before deciding if I change the pipes & / or pump.

Previously, we'd discussed the possibility of applying the full battery voltage to the servotronic valve to see if it would help identify if the BCU output to the servotronic valve was low.
I've now tried it & with a cold engine / fluid, it did make the steering at idle lighter. However, it was so light, I don't believe it was as designed.
With a warm engine / fluid, it makes no difference to steering effort at idle - presumably because, the rack is not getting enough pressure to make any difference when the servotronic valve is opened further by the application of 12v rather than BCU output voltage.
Driving the car at any speed with 12v on the servotronic is unnerving, atabove 30mph, the steering is finger light & makes lane changes with really minor effort ! Definitely confirms the valve works - lol !

I've also tried a different second hand but allegedly good BCU. It made absolutely no difference to the steering & while measuring the output voltage to the servotronic valve, I found it had almost identical output to my existing BCU.
Conclusion : the BCU is NOT the cause of my problem.

For anyone who's had the patience to read this far :
I've finally found a JLR Diagnostic chart for heavy steering with ZF Servotronic steering , confirming the very large number of potential causes. It was in a Jag Workshop manual - but it all applies to an RR too. I'll post it on the forum shortly to help the many with variations on the same problem.
Going through many different forum posts, it also confirms that suggestions that it's always the Servotronic valve or BCU are only correct in some of cases Paul,
2001 Discovery 2 TD5, 211,000 miles & climbing
2006 FFRR TDV8 Vogue 151,000 miles & now sold
Member of Midland (Land) Rover Owners Club, www.mroc.co.uk

I also have sporadic heavy steering but always seems to be on lift off when slowing down like slowing and turning into a driveway etc. so revs are dropping when the issue presents itself.

95% of the time its fine.

Sounds like you could have the same cause or possibly sticking servotronic valve.Try Gavin's test.
Warm engine at idle in Neutral or Park apply some effort to the steering wheel, but don't turn it, then increase the revs.
If the wheel turns, you've not got the intended max PAS pump pressure / flow. Paul,
2001 Discovery 2 TD5, 211,000 miles & climbing
2006 FFRR TDV8 Vogue 151,000 miles & now sold
Member of Midland (Land) Rover Owners Club, www.mroc.co.uk

Just fixed the heavy steering on my Td6.
Initially changed the servotronic valve, and it made no difference.

Ended up buying a used BCU, connected the RSW all comms to reprogram, and now sorted.

Richcl, Well done. It's always satisfying to get the problem solved.

It's always worth doing some fault finding before going straight to the "its always this " options.
For completeness on this post, here's a link to another post with I think all possible causes & some JLR fault diagnosis info :
https://www.fullfatrr.com/forum/topic50551.html Paul,
2001 Discovery 2 TD5, 211,000 miles & climbing
2006 FFRR TDV8 Vogue 151,000 miles & now sold
Member of Midland (Land) Rover Owners Club, www.mroc.co.uk

Got an issue with mine this week, wont self centre after going round sharp corners or junctions, steering gets stiff/heavy at the 10 and 2 oclock positions noticeably.
Been looking on here and other forums, its nice to read a completed thread and what did fix the issues on op posts. If it dont work.......burn it!

If the IId tool cant fix it.......burn the FF.

If the FF cant be fixed......buy a Land Cruiser!

If the LC cant be fixed..............................................BUY a horse !!

Hmm yours sounds like a seized / seizing U joint on the steering column Welshdragon.

Try giving the U joints a good dosing of WD40 and turn the steering lock to lock to work it in.

If it temporarily relieves your symptoms it could be time for a new lower steering shaft.

Yes, lower uj was the cause and when FF went in for MOT I got the mechanic to sort it......mind they change the lower 4 arms too as it failed the MOT on them!!
Funny how you don't notice the failing part when its progressive but now the FF is a dream to drive yet again.  If it dont work.......burn it!

If the IId tool cant fix it.......burn the FF.

If the FF cant be fixed......buy a Land Cruiser!

If the LC cant be fixed..............................................BUY a horse !!

Great to hear you got it sorted welshdragon.

I had to change all 4 lower arms and ball joints on mine when I got it as they were all worn and knocking.

Going to fit a new servotronic valve to mine tomorrow and if that doesnt sort it try a known good used pump fingers crossed.

Sadly my servotronic valve didn't turn up Saturday so no progress on mine yet.

Really frustrated with it at the moment, losing the love really quickly.

Don't know what I'll do if the valve doesn't make the difference.

[ i had them all changed to save chasing the issue, now steering is fine, so the issue was flow and not pressure due to a hose collapsing under vacuum and the extremely patient and value for money people who did this all for me. Steering Specialists in Wakefield 01924 26799 James Kenyon is the man to talk to , he especially likes changing serpentine belts ![/quote]

This sounds like the problem I'm having.
How many pipes were replaced do you know?
Also, what did it cost as a matter of interest please?

Cheers
Pete

** UPDATE**: Had the hoses changed (3 I believe), as Gavinn did, now working again, touch wood!

Last edited by abs66 on 5th Jul 2022 3:53pm. Edited 1 time in total

I cant help directly with your question but defo +1 for recommending those guys. Have done many power steering pumps for me over the years excellent service and prices, what ever the actual cost is I am sure it will be good value for money.