My aging 1989 XJ40 still has the hydraulic leveling system installed. Two issues:
1) I am constantly adding fluid though I can find no leaks-no green oil pools or streaks any where (as opposed to brown oil leaks on garage floor). Since the hydraulic system also supports the brake booster I am concerned with this fluid loss. Any ideas where it disappears?
2) Front shocks require replacement and thus probably rears. I would like to convert to conventional system for rears as fixing the leveling system is a costly repair, I am informed. Is there a tutorial on this forum (searched, nothing showed - this may be due to incorrect words for search parameter) similar to the post showing front shock replacement procedure? or some where else? There is a conversion kit available, but sure would like to understand process as to whether this is DYI or pro-mechanic required.

Thanks for any advice/comments.

 

Hey Ed.
If you look in the TSB section at the top of this (xj40) section you'll see a link to a rather long list of tech service bulletins. I just looked- number 64-14 refers to removing adaptive rear suspension. I didnt look at it in favor of refering info. Mine both Had the system and what remains is the hydro pump on the front of the motor, a plugged port on the reservoir and a few odd connections around the rear suspension area. I would "Almost" suggest just removing it all, plugging affected lines and installing standard strut units, but I am not sure of availability of complete units. I have replaced the struts only, retaining the same springs and mount pieces, but that was after the system had already been removed. Keep us posted and good luck.

 

Jerry: Thanks for the Welcome response; the number of forum members who went out of their way to say 'Hi' was really appreciated. I looked at the TSB you mentioned. On the surface it doesn't appear too daunting a task. I have also been looking at strut replacements; my usual sources leave something to be desired regarding whether the unit is for leveler vs. non-leveler vehicles as well as no mention of the kit to non-level. Will just keep looking as the weather is quite 'grungy' and will be for several weeks, maybe months. Again, thanks.

 

The 1988/89 hydraulic pump cannot be removed like the 1990-1994MY cars without altering the Power Braking System. The pump is used as the 'power assist' booster.

The SLS components can be removed and the original rear springs can also be used if they are SHIMMED. I usually install 2 THICK and 1 THIN plastic shim in the conventional damper mounts.

Just make sure that there is enough of the spring mount protruding to keep the spring 'centered' when installing the added shims. You might try 1 thick on one end and 1 thick/1 thin on the other.

The other alternative is to get the correct rear springs for the non-SLS dampers.

You could always 'GO ALL THE WAY' and install X300 lower control arms with the related springs/dampers!!!!!!!!!!!

bob

 

Bob: Thanks. I understand the pump must stay to support the brake booster. What concerns me more is where does all the fluid disappear/collect? I can find no connections that involve the power fluid with any other system other than the brake booster. There is no physical connection between the power fluid and the brake fluid. With this type of system leak I would expect to see large pools of green oil under, in, or on the vehicle. No such sighting. Maybe just another subset of mysterious Jaguar oil leaks designed as rust prevention? (As an aside, a Jag mechanic in San Diego CA informed that 'Jaguar' translated to American from British as 'oil leak')

As to the rear suspension/shock situation, changing to the X300 setup may be worthwhile if the wishbone kit and spring/shock kit are available. I will research availability.

You also mention plastic shims if using the existing springs. Are these available off-the-shelf? This is probably cheaper than the X300 route and some what less labor as long as the existing springs are usable. But I do like the X300 route.

Thanks again
Ed

 

The HSMO is for the BRAKE BOOSTER ONLY!!!!!!!!!!!!!!!
The brake fluid is for the BRAKE Master/Calipers!!!!!!!!!
They are separate systems, no fluid sharing.

When the SLS is eliminated in the 3.6 liter cars, the bleed plug from the LEFT rear damper is used to cap-off the valve block. You disconnect the metal pipe to the rear suspension at the valve block and install the bleed capping plug.

You need to unplug the SLS rear level sensor or the system might attempt to raise the rear if the sensor arm is set to compensate for a lowered rear end situation.
The valve block will then 'pulse' as the system pressure reaches MAX and the pressure regulator unloads and then the pressure builds again..the pressure regulator unloads and then the pressure builds again..the pressure regulator unloads and then the pressure builds again..the pressure regulator unloads and then the pressure builds again..the pressure regulator unloads and then the pressure builds again..the pressure regulator unloads and then the pressure builds again..the pressure regulator unloads and then the pressure builds again..

This is the ANNOYING thump,thump,thump,thump,thump,thump, 'pulse' that people hear when the level sensor is still connected.

Jaguar Publication S73 will describe the systems and the differences.

bob

 

Just a suggestion: if the high pressure levelling accumulator has no more pressure (nitrogen) inside, then the oil might be taking the volume left free by the nitrogen. If true this would tell the accumulator's inner membrane is out of order; a replacement of the accumaulator by a renewed one (Citroen shops have cheap ones) has to be considered

 

Chelmi: That is probable. And I may just replace the strut and continue to use the SLS system. Thanks

 

@ED: from what I have read on the hydraulic suspension systems, the accumulator part is rarely faulty (the inner membranne technology is robust and keeps the nitogen on its top without loosing gas).

I am willing to keep the SLS equipment on my recently acquired Daimler XJ 40 (1990 MY). But I have to find out why the 2 amp fuse (right box) is fusing after some time running. I will change the relay put in place by the PO and then initiate some testings.
Have a good day.
Michel

 

Wish I could help on the electrics. Looked at the electric diagrams in Haynes and could not find mention of the SLS but this was a quick look.
The accumulator and pump are probably fine as the brakes work very well. Still researching the strut replacement issue as I have time.

 

For those who have a car equiped with the SLS, I attach 2 pictures of the sensor itself, a Delco product.



Jag part DBC3439

 

After some work (opening the sensor and cleaning the outside contacts, and then refitting,

the result is: the levelling is operational; without any other action (even not the change of the relay (located in the trunk))

 

My '92 Sovereign originally had the SLS rear, which was converted by the dealer to Springs/Shocks early on. The rear was sagging noticeably when I bought the car and I had my Jag Indy install a new set of Springs, Bushings, Insulators and Sachs dampers. He had a supply of shims and when I got the car I was a bit worried about the rear end, it was a tad bit higher than I wanted. He said give it a few days and see.

Just like he said, I drove it for a couple days and checked it after a drive. It was **dead on**. It seems like something that definitely comes from experience. (Just wished he'd greased the upper foam insulators as my Right Rear is starting to squeak over bumps now... :/)

-Nick

 

Hello Ed

The previous owner of my 88 xj40 had the Jaguar dealership switch over to covectional system. I have all his receipts. Well they charged him $5000 dollars. I couldn't believe it, actually I want to look at it again just to make sure. On top of this I'm sure that they kept and sold his parts. I believe that this is why he let the Jaguar go after the brakes were leaking, because it just seemed like they were gouging him every time. Best thing to try and do it yourself, maybe with someone holding your hand. Hopefully you find your parts. Good luck.

 

I have located most of the parts I require. Now I am trying to locate the time to do the work. Always waiting for something!

 

That's great Ed.

It took me a year to actually get started on the Jag.
It was so hard, that I would avoid this forum.
My birthday is coming up so maybe I will aim for that.
Whatever you do Ed make sure to take you time and double check.
Is there anything else that you can attend to while you are changing the parts.
Good luck to ya!

 

I can swap an SLS system to conventional springs/dampers in less than an hour. It is not hard......The first time will likely take 4 hours but after several dozen, the task become mundane.

If you have a complete set of dampers/springs and do not need to use any of the original components, you just assemble the units beforehand and swap them out. Remember to turn the spring/damper so the 'hats' (upper spring mount/retainer) are 180 degrees to get them clear of the frame/suspension and pull them out the top. You might need to pry down on the lower control arm a little.

I used to reuse the SLS springs and add shims to compensate for the shorter length.

The correct springs are more costly but are better if you can find/afford them.

bob

 

Bob: This means you have access to a lift, which I do not. Will be doing this one corner at a time using jacks and stands for support. The nearest Jag shop is 60mi south after a 2hr ferry ride and no 'rent-a-lift' here on the island. So, back to the old days for me.

I have not found replacement springs, at least any that specifically note XJ40 compatibility. Shims are readily available. Will expand my search for these as I am concerned that the existing springs are kaput.

Thanks for your advice and interest in this project.

 

Ed,

Regarding replacement road springs, check with our forum sponsors SNG Barratt, Coventry West and Jagbits. You can also check Welsh Enterprises (I think I recall seeing the rear springs on their website for an attractive price), Terry's Jags, Motorcars Ltd., etc.

Cheers,

Don