Has anyone addressed the usefulness / cost effectiveness of the several ideas offered to forestall the Green Shower? In Stickies only two are addressed: the resistor method that drops the voltage to the hydraulic motor, and the pressure relief bypass device. There is no mention of the simple internal spring replacement that can be performed on the latch 'circuit' and, if desired, on the piston 'circuit'. It seems to me that if the pressure can be relieved by way of Dennis White's approach that a pressure reduction by this means would trump other, more expensive methods, and the resistor voltage dropper too because even that is more expensive than changing a spring, and it has the disadvantage of slowing down all aspects of the operation of the top. Any comments before I start down the internal spring path?

 

One of the very first things that I did was the manual latch conversion. I also put a resistor on the pump. I now have ZERO risk of green shower because the latch has no fluid running to it AND the resistor reduces the pressure to the rams so I hope that they will last longer as well

 

I am about to do the manual latch conversion as well. Just 2 days ago I noticed that my latch would not retract into the windshield frame after the top is down (but strangely enough the latch does pull the top closed and will release it again) ....then I looked at the little grille and noted it was slightly wet but not dripping. I'm afraid that if I keep using it the line is going to burst (is this a reasonable assumption?) so I ordered the parts for the manual conversion until I can repair it.

 

I just went to the local hydraulic shop and they had the fittings in stock. Cost me just over $3 cdn. ☺ Pretty much everybody carries metric fittings these days

 

I'm a bit puzzled regarding the resistor approach: If that resistor is placed in series with the motor wouldn't that affect everything operated by the pump, such that rams and latch will all get weakened? Doesn't that mean that the risk of a latch line causing the Green Shower is lessened, but not zero?
Also, could you please be more explicit about the exact modification you are referring to? I got the resistor volt dropping one, but there are several possibilities with the hydraulic / mechanical approach. Namely, the pressure can be reduced by means of a weaker spring in any particular 'circuit', and that can be done either by changing the internal pressure spring(s) or by piping a (weaker spring again) bypass and return system.

 

Yes the resistor does indeed reduce pressure to the entire system. I used the resistor because it is so simple to install and works very well. Because of the reduced pressure, the hood cycles a bit more slowly but still opens or closes in about 30 seconds.

 

My risk for green shower is reduced to zero because i also used the manual latch conversion which takes the hydraulics out of the latch entirely

 

Gents, descriptions of the internal-spring pressure reducer, the manual-latch mod, and the resistor mod are found through three links in my sig. line below. I wish these were all in the stickies. There is also a mod where an external relief valve is fitted (similar in function to the internal spring replacement) but I did not work on that.

Only the manual-latch mod completely eliminates the possibility of a green shower, but I think we have good reason to believe that the other mods improve the odds of avoiding one. The spring replacement is probably more effective than the resistor (but there is more to it than just comparing peak pressures; the "shape" of the pressure pulses matters too). The spring replacement is a more challenging installation than the resistor.

As noted above, the resistor does slow everything down a bit. When we worked on that (Reverend Sam and I) we did not know that it would be possible to replace the internal pressure-regulating spring.

 

Well done, Dennis. It would be great (but rare) at a time like this to know how many springs have been changed and how many, if any, showers occurred subsequently. Similarly the other methods. Many thanks for your effort.

 

Followup questions, if I may: Your description of the internal spring replacement doesn't mention the removal of hydraulic lines and connections. May I assume that no disconnections are needed, and that the drainage and housing removal can all be done in the trunk (poised on a box / support)? If not, there are O rings to be replaced on the hose lines, per the W/manual.
Second, does 'open the petcock' mean the top filler / drain plug as shown in the Jag W/manual?
Should the convertible top be up or down? The W/manual says to lower it, but I assume that is because, if one were changing out the pump, more fluid would be in the reservoir. For the spring change, it wouldn't seem to matter what the amount of fluid in the reservoir is
Thanks again!

 

This thread got me searching for all things "green shower" related on the forum. I was trying to decide which mod I was going to do; higher quality hydraulic hoses, manual release, relief valve or resistor. Then I stumbled across a post stating that the 97's had higher quality hoses than the 98 and following had and were not susceptible to green showers at all. Whew, now I can get back to worrying about my Nicasil cylinder linings, water pump impeller and plastic coolant pipes.......but even before that I've got to get my door locks to function again...

 

Soon after acquiring my 2004 XK8 I reduced the pressure using the relief valve method. I think that any method that reduces the pressure will give you longer life but not endless life, particularly if you live in areas where hot climates really cook the lines to the latch. I doubt the 1997 models are immune entirely. They just enjoy a longer life than later years.

After I replaced the latch lines with higher quality versions I don't expect to ever have a problem. Replacing those two lines was not difficult just slow and tedious.

If you have not replaced your latch lines and reduced your pressure somehow then you can eventually expect a fate similar to poor Johan .

 

Please note that the above video's audio is "Not Safe For Work". If you are in an open office area or if your kids are nearby, put your headphones on before you play the video....

 

They are now Dennis, I thought they were already.

 

AtLastaJag,

Something close to 70 springs have gone out to date. I have not received any feedback on subsequent hose failures or lack of same. But then again I did not ask for any, so I just don't know.

You may be overthinking the installation. No disassembly required beyond what is specified. Convertible top can be up or down.

 

I checked the hoses on my '97 today and it does have the 600BAR rated hoses so I *should* be OK.

 

Dropping the pressure anyway will help the seals in the latch and cylinders last longer.

 

Spring modification complete, but top not functioning; perhaps someone can shed light? Per Dennis White's instruction sheet, I changed the spring in the left hand pressure relief, and calibrated the valve. The top was fully down and the petcock opened, and the fluid (which was actually at the wrong level - being at the lower reservoir mark, rather than at the top - was duly drained. I replaced this with fresh Pentosin. Bottom line: the top will raise only about 6-10 inches and then comes to a halt, with the pump not sounding happy. I can lower as usual from this position but I can raise above it. I have asked Dennis - he has the earlier model pump unit with the three hex shaped valve bodies - whether there is any possibility that the valve functions are reversed in the later models. Doesn't seem likely, but then neither does Jag changing the perfectly serviceable hex bodies into smooth cylinders that require vise-grips to undo!). For full disclosure: pay attention to Dennis' warning about breaking electrical connectors! I didn't pay close enough attention and had to remove the solenoid valves for a surgical repair. I doubt this has anything to do with the problem, as I seem to have raise / lower functionality; just not enough apparent 'oomph' for the former. Suggestions would be very welcome!.

 

Wondering if it just got air in the system somehow.

I think if you open the pressure relief valve and work the top manually that will work out any trapped air back to the tank.

After a few manual up/downs see if it will unlatch and open from a completely closed/locked starting position.

 

Thanks for the response. As I understand things; from the WM the system is supposed to self-bleed. I don't know how it actually does that. But I can now post the solution, which was provided by Dennis White. I am certain that my setting of the zero-pressure point with the new weaker spring was correct, so Dennis' conclusion was that the spring must be at the weaker end of the specification, which he states as +/- 10%. Another 'flat' of rotation was added to the pressure relief screw, and the top raises perfectly again. Hopefully, with less power than it takes to blow the latch line and cause a Green Shower!
The project is straight forward enough, except that I wasn't properly alert at the time, and didn't see that there is a master connector that disconnects the two solenoid valve lines. It is located on the box that houses the CD player, approximately at the height of, and facing the back of the P Side rear lights. The main power connector is near the petcock and is pretty obvious. The connectors on the solenoid valves themselves are nigh-on impossible to get off, even with the pump out in the open, and certainly not with it installed.
The tubular pressure relief valves of the more recent MYs is a giant step backward, except that it allows for the easy addition of a hose for zero-pressure testing; I am guessing that the hex style is more problematic. Other than that: I hate using vise-grips on anything!
For the second 'go around' I opted for a MityVac as a means of draining the reservoir, rather than a syringe. The MV has to decanted twice; that's all.
Thanks for the input.