Jaguar Roof Hydraulic Upgrade Kit
This page has been set up to provide information and guidance for individuals who would like to purchase the Hydraulic Upgrade Kit for XK8/XKR vehicles Model Years 1996-2006. If you have questions about compatibility, compare your pump the one pictured below. Please note that this kit is designed to allow the roof system to operate fully without risking damage to the pump motor. Do not confuse this with cheap fixes that starve the motor by inserting resistors in the motor circuit. This causes the motor to run excessively slow, does not eliminate the dead head problem, and will ultimatelly damage the motor. The kit sold here allows the motor to run at its full design speed and only acts to reduce pressure at the critical point after the work has been done. The problem with the original system is caused by the pump being held on after all motion has stopped, resulting in dead head high pressure spikes and extreme stress on all the components. This kit eliminates those factors and as a result will increase the reliability of all components including the latch hoses and lift cylinders.
The President of LSI Controls (Walt Nuschke 00XKR Conv) is also the owner of a 2000 XKR and became interested in this problem through participation in various forums and his own difficulties with the roof system in his car. LSI Controls has tested the hydraulic system that operates the roof and configured a kit that will improve the reliability. This involved tearing apart a pump to discover how it works and installing a pressure sensor to measure the operational requirements of the system. From this it was discovered that the pump generates 30-40% more pressure than is necessary to operate the system. The upgrade kit is designed to regulate the pressure which will relieve stress on the components. Less stress equals longer life. Read on to learn more.
The kit is available for $279.00 plus shipping and tax directly from LSI Controls. The kit includes the parts shown above. Detailed instructions for Do-It-Yourself installation are available via the download link below. Installation takes about 30 minutes and requires no special tools. The contact information is available at the bottom of this page. Major Credit Cards and Paypal are accepted. Delivery is dependent on availability but always within four weeks and usually faster depending on factory stock.
Please take notice of the new price of $279.00. Due to high demand we have been able to increase order volume with the valve manufacturer and pass the savings along. Pennsylvania Law requires that we charge sales tax on domestic orders.
To Buy: If you want to use Paypal, you can click the "Buy It Now" Icon at the bottom of this page and follow the instructions on the Paypal site. Due to the cost of this item we will ship by FedEx or UPS in order to get full shipment tracking and insurance. We can ship USPS for lower cost, but this does not give the tracking and insurance features. To ship USPS, with tracking and insurance, costs more so we don’t use this. International shipments can be FedEx, UPS, or DHL by special arrangement. Credit Card purchases are done by contacting us directly (see info below) to make arrangements.
International Buyers: Shipment via FedEx, UPS, and DHL is expensive but does provide tracking and quick delivery. We can also ship through the postal service for about 1/3 the cost but there is no tracking and delivery can take a long time. These options are available on the Paypal account or if you come to us directly.
Background Information:
This upgrade kit is designed for the Jaguar XK8/XKR model years 1996-2005. The automatic convertible top in these model years is operated by a hydraulic system manufactured for Jaguar by the Power Packer company. Power Packer is the primary designer and manufacturer of convertible top systems that are also used by a long list of car manufacturers. This system has suffered from a variety of premature failures. The kit offered here is designed to overcome flaws in the design of the Power Packer roof system and improve reliability.
The failures, in approximate order of severity, have been the latch hoses, where they fasten to the latch cylinder, the latch cylinder seals, the lift cylinder seals (located behind the rear jump seat on both sides), and sporadically hoses in random locations.
The observed failures have been in majority related to high operating temperatures in the latch area. Hydraulic components are rated by maximum operating pressure and temperature. These two parameters interact such that a hose with higher temperature rating will have lower pressure rating at that temperature and visa versa. The operating temperature in the Jaguar is beyond our control (talk to the Sun about this) but this upgrade kit is able to reduce operating pressure by over 30% without affecting operation. This large pressure reduction therefore increases the safe operating temperature range of the system. The relative effect amounts to about 600 pounds of force that no longer must be contained by the hoses and seals.
Model years up to about 2001 used Nylaflow hose manufactured by Parker. This hose was particularly unreliable. Later models have Polyflex hose (also manufactured by Parker) installed. Polyflex hose has performed better but still has an unacceptable failure rate in this system. Both of these hoses are custom for Power Packer and not commercially available. The name of the hose and product number (363) is clearly printed on the hose. Also printed on the hose is a date code in the form “1-Q-03″ which in this case is the first quarter of 2003. This date can be matched to the model year and other hoses in the system to diagnose what has been done to the hydraulic system in the past. The installation of hoses of different type and/or date code is an indication of prior replacement and subsequent years of service.
The hose connection at the latch has the highest failure rate due to high temperatures from the sun in this area. Failures in this area are immediatelly recognized. The lift cylinders, located on both sides behind the rear seat, also fail but at a lower rate. These cylinders develop leaks in the shaft seals that gradually escalate. If the hydraulic fluid must be repeatedly topped off this is the likely cause. A leaking lift cylinder will leave a small spot of oil on the ground directly in front of the rear wheel.
The graph below shows a comparison of hydraulic pressure as the roof is raised. A pressure sensor was installed in the hydraulic lines and the data recorded by a computer. Data for Stock and Resistor were taken from the same car. Relief Valve data was taken from another car fitted with our Upgrade Kit. Resistor data is shown because some have been erroneously led to believe that this is a cheap solution. The graph below clearly show that this is not true as the pressure is only reduced by 3.5% while the lift time in increased by 25%. In this comparison the Relief Valve reduces pressure by 42% although exact values will vary due to mechanical tolerances. The primary area of concern occurs at the end of travel in the area labeled "Dead Head After Latch Closure". This is the point where the roof controller holds the pump on after all motion has ended which causes the pressure to spike. This pressure spike is what accelerates the degradation of the hoses and cylinder seals.
You will note in the graphs abovethat the peak pressure with a series resistor is about 500psi higher (1578 vs. 947) than the peak pressure with the relief valve in our kit. One way to appreciate this would be to load a barbell with 500 pounds. The round end of the bar is about 1 square inch so the pressure exerted will be about 500psi. Pick the bar up (with the help of several friends), holding the bar verrtical, and drop the end (to simulate the pressure pulse) on something you don’t care to see again. This will give a good approximation of the amount of force that is removed from the roof system by the kit offered here.
Shipping and Mailing Address:
LSI Controls Inc.
11664 Orchard Road,
Waynesboro, PA 17268
Phone: 717-762-2191
Fax: 717-762-0863