Hi all once again,

Due to other commitments I haven't finished the PAS conversion yet. The box, idler, pump etc are all in place and the wiring is ready to connect. I'm going to try out the system (provided it works - lol !) before I consider the
fitment of the 'controller'. I read on the Wilkinson site that the Vauxhall/GM pump automatically reduces/increases assistance upon certain driving conditions - don't quite know how that happens but I'll give it a go. I'm hoping to complete the installation next week so will report back (fingers crossed).

 

UPDATE:

All wired up and all hoses now connected. Started engine and ignition light went out (replaced the 45 amp alternator with a larger version). Pump makes a slight 'buzzing' sound. Lowered car onto wheels and turned steering wheel lock to lock to bleed system. Seems to work OK - certainly less effort to turn steering wheel with wheels on the ground. Quite relieved really as I didn't want 'too' much assistance which would remove any feel. Unfortunately I couldn't road test the car today for various reasons and, of course, I need to get the tracking checked and adjusted at a local tyre depot. Will report back in due course.

 

Hi Everyone,

Took the car out for it's first half-decent run today. All seems Ok but I expected more assistance that I'm getting. The tracking needs adjusting obviously so I'm wondering whether that has had an effect (?). How have other forum members found the assistance given with using the Vauxhall/GM pump (steering box or rack) ? I used to have a Series 1 XJ6 and, as I recall, that steering was a lot lighter.

 

Hi Cap'n. Just out of interest how have you connected it up? Does it come on when ignition is turned on or when battery starts charging?
I have found that the steering in my S type is a smidgeon lighter than I would have liked but its within the acceptable range.
Does yours have even steering effort at all points in the lock to lock range?

 

Captain ~ Have you measured the pressure you have at the entry to the PS Box? Do you know the health of the Opel/Vauxhall pump?






These are values of pump pressure used by Jaguar with Hobourn Eaton roller pumps mounted to rear of generator and later stand alone Saginaw pump fitted to the 420 with Varamatic. These direct from Jaguar factory service bulletins.

S Types: 4 Steering types.

Manual
First Type Burman PAS Box with Hobourn Eaton roller pump ~ 800 - 850psi (only very early cars ~ mainly fitted to Mk2's)
Second Type Burman Box with torsion bar quill valve & Hobourn Eaton roller pump ~ 1000psi ~ fitted to most S Types (Mk2's similarly updated)
Marles Bendix Varamatic (Adwest) Box with Hobourn Eaton roller pump ~ 1000psi ~ fitted to late S Types.
Marles Bendix Varamatic (Adwest) Box fitted to 420 with Saginaw pump ~ 1200psi

Truth of the matter is all seem to work together.
Common complaint is that steering feels overboosted.
Varamatic gives best feel.
I would not fit a 1200 psi pump to a 1st type PAS Box. (apparently known for distorting their top & leaking)

 

Thanks for that information Glyn - it will probably prove invaluable. The Vauxhall/GM pump certainly seems to be spinning up and, when on full lock, I can also see the Ammeter swing to the 'discharge' side so seems to be doing
its job. As to it's condition - really don't know. I do have a spare one but the wires were cut short by the person I bought it from. My first plan is to get the tracking checked & adjusted as it may be way out (that's if the local tyre
depot can use their alignment gauges on the wire wheels - they think the spinners may get in the way !). Alternatively I'll buy one of the Gunson Trakrite gauges and set it up myself.

One thought I had this morning (thanks to 'wouldbeowner') was whether the way I've wired the motor in may be the cause. I've retained the original wiring loom, connected to the alternator with its normal Lucas Spade connectors. I've then used the stud take-off on the alternator to power the pump, via an 80amp fuse. I did wonder whether the voltage output would vary depending upon the cars requirements, thereby NOT supplying 12V to the pump. I've just checked the voltage and the fuse block and it's in excess of 12V - so presumably that's not the cause of my poor assistance ??

I do have a pressure gauge (used it to check/adjust my overdrive when it wouldn't kick-in) so, after the tracking I'll do as you suggest and check the pressure. Thanks again (and thank you 'wouldbeowner' )

 

It would seem your power supply is OK but worth checking that voltage is not sagging when you load the pump. Otherwise a pressure check is vital to proper operation. Trust the PS Box is in good fettle. They are tough old things when free of leaks.

As a belt & bracers approach you might need to bleed at Bleed Plug 6 to ensure no air in the system.

 

Pressure should be measured at full lock! (Sorry ~ I nearly forgot)

 

Thanks again Glyn. I think my first approach will be to check the voltage with the engine running at different speeds whilst turning the steering wheel, to see if the voltage does indeed drop. Failing that I'll do as you suggest and bleed the box via the bleed plug (engine running). I would like to do a pressure check but don't have the required adaptor at the moment to fit the gauge to (I think it will be 1/2" UNF with a 1/4" NPT take-off ?). Nobody said doing such a
conversion would be straightforward - lol !).

With regards 'wouldbeowners' comments about how I've wired the pump. As I have retained the original wiring loom (albeit a new one) I have connected the two original wires connected to the Lucar tags on the alternator. As I had
previously fitted the alternator and dispensed with the Control Box the Brown/Yellow and Brown/Green wires (to ignition lamp on dash) were joined together (where the original Control Box was situated), so I connected the Blue/White wire from the new pump to them. The pump only operates when the engine is running. I hope I've done it all correctly - I noted yesterday that the Wilkinson (steering rack) instructions show the pump feed coming from a junction box where the outlet from the alternator and from the solenoid join together. I've taken the pump feed directly from the alternator via an 80-amp fuse (using the stud outlet).

 

UPDATE:

Tested voltage at all speeds - steady in excess of 12V. Ran engine and released the bleed screw - turned steering wheel side to side a number of times. Some fluid came out so believe any air (if any) was released. Steering still doesn't seem to be as sensitive as thought it would be - I've certainly got some assistance but perhaps I'm expecting too much (I have got radial tyres instead of crossply AND a heavier 4.2 engine after all). I've still got to get the alignment checked/adjusted so I think my best course of action is to see how things are after that before delving further. The daft thing is I didn't want too much assistance so I don't know why I'm concerned - lol (It's just that I thought there would be more, that's all). As Glyn said, a pressure check is the ultimate answer.

 

How does it feel at speed going down the road ?

 

Hi.
Can’t really answer that just yet - I need to get the tracking set up ( I suspect it’s way out and I don’t want to wreck the tyres). Will update when done.

 

Hello again everyone,

Latest update: I've managed to rig-up a pressure gauge and the pressure seems fine (around 1000psi on either lock). However I've noticed something that MAY be the cause of the lack of full assistance - the pipe that connects the
front inlet port to the top of the box (feed pipe) has quite a severe dent in it. Having studied the workshop manual it appears that the fluid entering the top augments the pressure provided by the spring on the rocker shaft. The rocker shaft, in turn pushes down on the main nut. What I'm thinking (I may be wrong) is that it's feasible that the pressure in the feed pipe is increased due to the restriction (??) thereby applying more pressure onto the main nut. In turn that may cause more effort to be required when turning the steering wheel (??). Does anybody agree or disagree with that theory ??

 

The theory is probably debatable but the fact remains that the connector pipe should allow unrestricted flow of fluid (not that there is much flow in that pipe). How bad is this dent? Those pipes are generally available but are LHD & RHD ~ I'm pretty sure with proper bending gear one could configure one for the other. Barratts only have LHD stock at the moment.

 

Good Morning Glyn,

The dent is quite bad (box is obviously on the car now so not easy to photograph). I was aware of this before I fitted it but was of the opinion that although squashed the actual internal size would still be the same and therefore pressure wouldn't be affected (??). In light of the subsequent problems I now realise I should've replaced it anyway. My box is the earlier version of the Burman type which has a simpler 90 degree feed pipe rather than the looped one fitted to the second version (my original part number being C16103, whereas the 'looped' pipe is C23372). It looks like the banjo fittings on each end should fit OK so I've decided to go for SNG's left-hand drive version (C23373) and bend carefully where necessary - there must be a reason for a LH and RH version (presumably it will foul on something and probably 'loops' the opposite way). I've just placed the order so will post the outcome in due course (we're going into a 4 week lockdown over here as from Thursday so I'll have plenty of time to get my hands dirty - lol !). Thank you for your advice

 

So you have the Burman First Type like this.







And you are going to modify this to fit. Should be fine.






Damn Barratts have always had their "early" & "late" (First Type & Second Type) transposed on the S Type web diagrams.

 

There is no real flow through that pipe, all it's doing is allowing the fluid under pressure to hold down the drop shaft, it helps to keep the rocker shaft (refer to #1 in the diagram) in contact with the main recirculating ball unit.
I don't believe that replacing the pipe with one with out a dent will change anything.
If you think the steering resistance is still too great, I would check the idler shaft in the steering linkage itself, it should move freely with no play when tested with your bare hands.

 

Yes ~ that's why I commented "(not that there is much flow in that pipe)" Probably only some leak past. If this achieves nothing then the problem lies with the PAS box itself. It's possible I suppose that the pipe is blocked at the dent due to debris although the fluid is filtered.

I think CaptainQ needs to drive a similarly equipped car as a reference.

 

I think you have hit it on the head there Glyn. We do tend to compare the feel of our 50 plus year old Jaguars with our modern cars and there is no comparison. Even though Jaguar were a high end car when new in the 60s technology has moved on so far that although we call modern steering by the same name, ie Power assisted Steering the way the power is generated then applied to the steering, the joints and bushes, electrical sensors adjusting the power and feel a thousand times a second, tyres and suspension they are now so far advanced that the only comparison is really in the name. To judge how the steering is working you do have to compare like for like and go an drive another 50 plus year old Jaguar with power steering to see if it feels the same as yours.

 

Hi everyone,

Unfortunately I can't do a comparison with other cars (particularly as we're about to enter a 4 week lockdown). I used to have a S1 XJ6 and I seem to recall that the power steering on that car offered more assistance than my latest set-up (but then again memory does play tricks - lol). I won't lose anything by changing the feed pipe (apart from £50 !) so I'll do it anyway - should be arriving today. With regards the idler and other linkages, they've all been replaced and seem to move freely enough, so I don't think they're the problem. Before I did this conversion I was concerned that I would have TOO MUCH power assistance not too little, so I don't know why I'm concerned really - I just don't like things not working properly. I have dropped a heavy 4.2 engine into the car AND I've now got radials instead of crossplies so I suppose that's bound to offer resistance (I haven't checked/adjusted the tracking yet either so that may possibly add to the feel ???). Thank you to everyone for your input - it's really appreciated (I'll report back in due course - there will be a delay however as both my elderly parents have gone down with this terrible Coronavirus and my other is very ill in hospital). Stay safe everyone.