Hi Everyone,

I've been attempting to determine if the pressure reduction kit created by an Online member here is still available for purchase. It was from jag repair. I e-mailed, but haven't heard a response. I also called a number found through another site, but they stopped stocking them. Any advice/suggestions? I'm really eager to get this installed.

Thanks!

 

Sorry! I responded to your PM.

 

there is a voltage and pressure reduction mod

 

Here is a link to the mods: http://www.scorekeeper.com/jaguar/jaguar01.htm
The installation video shows the kit but you don't really need a kit just the resistor , bit of wire and some spade connectors. You can order the resistor here: Chassis Mounted Aluminum Shell 100W Watt 0.2 Ohm Wirewound Resistor | eBay

Steve

 

Right you are. The kit shown in the video was offered by a one-time regular here named Reverend Sam. I don't think he's making these at the moment, but his email address is shown in the first of the two links Steve noted if you want to reach out to him and see.

 

Adding the resistor is as simple as that . . . you just add the resistor in the wiring connection to the pump. Sam's 'kit' added male/female connectors that permitted installation without cutting any Jaguar wires. It doesn't matter which wire the resistor is installed in as the B+/ground is swapped during pump operation.

https://www.jaguarforums.com/forum/x...ressure-53086/

I initially used Radio Shack spade connectors but the proper connectors are available here: https://www.jaguarforums.com/forum/x...e9/#post329037

I added 1" diameter heat shrink tubing around the resistor more as a heat alarm than insulation. It shrinks at 170 degrees (F) and has not. That would seem to indicate that mounting the resistor to the frame as a heat sink is not required.

 

Completed my install this evening and all working perfectly.
As suggested I tested with engine off and all was fine first time. Really slows down the opening and closing time so you can appreciate how it must take the pressure off the hoses. Had a little moment when the latch didn't go down but just needed a few more seconds.

I only did a single cycle to check operation - the resistor certainly got warm.

Really simple as said before - 100 Watt 0.2 ohm resistor with heat sink £3 from ebay. I had some heat resistant to 90 degrees centigrade earth wire left over from a HiFi project (needs to be a heavy cable to take the load) and found 4 spade connectors in the shed. Heat shrink the connections and tape up the spades where they go into the black connector block to prevent them touching as there is not much room in there. I also used some thermal conductive paste on the underside of the resistor and then self tap screw onto the top of the CD/Nav cradle to get a firm interface to help with the heat transfer.
My setup isn't as neat as those with the bespoke connectors but all the wiring is tidy and out of sight. However, now I have it all up and running I will probably shorten the cable lengths and get some better quality insulated spade connectors and do away with the insulation tape to tidy it up.

EDIT - Now tidied up the wiring - looks better. A small point to watch out for - with the shorter wires and with the resistor mounted on the rack need to be careful the wires don't get bent back/break when the boot liner is refitted as it can snag.

While the soldering iron was out I took the opportunity to run extra earth wires from the rear light earth rails to the mounting bolts as described elsewhere. I'd never had an issue with lights or melted wires but better safe than sorry.

Steve

 

I'm still wondering if there are far fewer green shower failures in the UK vs. the US due to a more moderate summer climate and therefore not nearly as much sun-baked damage to the hydraulic hoses and seals....

And yes, I know that there are considerably fewer ragtops in the UK vs. the US....

 

I'm convinced it's exactly as you say. Exhibit #1 of evidence: both ends of a latch hose see exactly the same pressure pulses. Yet the failures occur almost always at the latch end, not at the pump end.

What's different? The environment: heat and maybe mechanical stress occurring at installation. If it were primarily the latter one, they would see as much of it in the UK as we do here. I think heat is the biggest enemy.

 

Yall need to look at this. The top lines are flawed from the factory.

Convertible Top Hydraulic Hose Assembly Jaguar XK8 XKR 1997 2006 HJB8256AB | eBay

 

I don't think there is any doubt about that, but the majority of failures are at the latch end so it seems fair to assume that heat could play a part.

 

Looking at my paint on the outside of the car in that area, there is no doubt,heat plays a factor

 

Heat and pressure are both factors in the hose failures and failures have been identified in the trunk area but not as frequent. The one main contributing factor in the failures is that the hose installed for this application by Jaguar were under rated with the exception of a few earlier 97xk8 that were fitted with a higher rated hose.

As for replacement hoses I only know of two that I can say meet the needs and they are both on my page Top Hydraulics and the other is from Colliflower. FYI - I make no money on any of them! I know nothing about the other hoses except that they are using my name and were using my photos.

When attempting to lower the roof make sure not to force it open by hand. Now when replacing the hoses you will need to refill the fluid up to the top line then operate the roof and check the level again. This system is self purging!

 

Fortunately I have not experienced a hose failure and hopefully having fitted the voltage reducing mod (and being in the temperate UK) I will be OK but it struck me that if it's the connectors/joint that fails as opposed to the hose is it not possible to splice in a new uprated connector to the existing hose with a joining section rather than replace the entire hose?

 

Jaguar tried that to reduce warranty repair costs and experienced very poor results.

 

Probably used the same poor quality connectors as the originals

 

Their repair kit involved making a splice within the windshield pillar, if I remember right. The MTTF on these was about 3 days. (OK, probably more like a year or so, but not good.)

I think you've got a good shot at your hoses surviving now. This is only one data point, but I just parted company with an '01, 95k miles, still running its original hoses.

People here have started to think about heat but if you go back, say, a year or more, the posts concerning the hoses seldom mentioned it. I think if someone were to come up with a way to cool things down around the latch, it could be as important in reducing failure rates as what's been done about hydraulic pressure.

 

So is an air-conditioned latch on someone's drawing board now?!

 

Do we know if there are similar problems in Saudi ?

 

This is the repair connector that was a failure from the onset.

Link http://www.jagrepair.com/images/Auto...Connectors.pdf
Link http://www.jagrepair.com/images/Auto...structions.jpg

As for the locations of failures no one has taken the time to do an inventory. A thread was started to identify MY on this forum but not sure it is accurate.