Date of issue 08/99 Amended 04/03 Bulletin Number 501-33 Page 1 of 6
Slow Operation/Erratic Latching –
Convertible Top –
Some 1997-99 MY XK8 Convertibles may experience slow operation of the convertible top, or
slow or erratic operation of the latch. These conditions are caused by a tendency of the Univis
hydraulic fluid in the system to slowly evaporate, and in certain conditions to gel within the
hydraulic system pipes and hoses. From VIN 037189, vehicles in production have been filled
with an improved fluid, Pentosin CHF 11S.
The condition described above is more typical of a vehicle used in moderate to high ambient
temperatures and when the convertible top hydraulic system has not been actuated for some time.
On a verified customer complaint of slow operation or erratic latching of the convertible top,
check the hydraulic fluid level within the reservoir, and if low, top up using ‘Pentosin’ fluid (Part
No JLM21112). Cycle the top fully open and closed several times to see if the performance
returns to normal. If the concern is still evident, then carry out the workshop procedure outlined
If all other potential causes have been eliminated, it is necessary to flush the hydraulic system
and change the fluid to ‘Pentosin’ (JLM21112). This should be performed on a customer
complaint basis only, on vehicles within the above VIN range.
Caution: Only use Pentosin fluid, JLM21112, for topping-up or
refilling the hydraulic system on any XK series convertible. Do not use any
other type of hydraulic fluid.
1. Remove luggage compartment carpet.
2. Remove luggage compartment front liner. (See Workshop Manual, JTIS CD ROM, section:
501-05, SRO 76.19.31).
3. Remove luggage compartment right hand side liner. (See Workshop Manual, JTIS CD
ROM, section: 501-05, SRO 76.19.22).
Remove and destroy Bulletin 303-33, dated 08/99.
Replace with this Bulletin.
The procedure has been revised.