I Just changed the coolant in my New 98 XK8. But I can not find the purging screw, or how do I purge the coolant system?
Thanks

 

I am not sure what you are looking for if it is the drains, you have two lower right corner of radiator facing out, also another on the block rear left side of cylinder block. If it is the coolant tank it is on the top left near the firewall.

 

If you mean getting the air out of the system it should take care of it by itself. That is assuming it has an OEM thermostat with the 'jiggle' valve. Just check the overflow tank in a few days and refill as required.

 

We pour coolant in to the coolant system, in order to start the engine I kept the engine running for 4 to 5 minutes , I saw that in the dash board the temperature needle did not move at all. this may be related to the purge. Also I need to be sure that coolant fans will run, when the vehicle need it. So I maybe thinking that there maybe be air locked inside the coolant system. So I would like to bleed the system. There should be a bleed screw or valve in order to purge the air out of the coolant system. That what I am looking for. If there isn't, is there a proper procedure in purging the coolant system.

 

The bleed valve, not really a screw is located on the thermostat tower. It is the large screw cap and the highest point in the cooling system. It would be loosended, not removed, to bleed any air, then closed back to a prescribed torque setting. These a common leakers so it is seldom used for its intended purpose. If you want to ensure it doesn't leak, and before you pressurize the system, remove the cap and wrap the threads with teflon tape, then the cap will seal properly at the proper torque.

 

Also be very careful not to crack the plastic top with an Allen wrench. That is why it is seldom used.

Just drive it and top off the overflow tank.

 

I agree with Tom (TestPoint).

 

Driving it usually works and eventually purges the system of air. Every once in awhile there is a stubborn one that will continue to circulate air through the system and stay trapped behind the thermostat which can be heard in the cabin. The bleed was provided for commercial repairs as it will release air in the system immediately after a cooling system repair because a shop cannot deliver a car to a customer that way, or end up with a return simply for air in the system. But for DIYers, quick or slow becomes a choice.

Wise words on tightening the cap - Every time I've run across a cracked cap it is because someone cranked down on it with dry threads, usually trying to stop a leak, and far beyond the torque spec. It is going to crack if overtightened and very lucky if it doesn't.

 

Thank you for your responses.

By the way,

Any recommended sources to find the torque Specs for the Cap?

Or even a repair manual.

 

Complete JTIS manual is available as a free download on this forum. Such service!

https://www.jaguarforums.com/forum/s...ead.php?t=9933

 

Can someone help me with my problem, you do not know what I mean talking about/thanks

 

OK, thanks

 

A mechanic told me a good way to get all the coolant around the system.

keep squeezing the big lower hose on the xk8 that goes from the thermostat to the radiator and it will pull all the fluid through and keep topping it up till it stays at a constant level in the expansion tank

 

This excellent tutorial from MrTexasDan describes the coolant plug on the later XKR's in step 8 (mine is just like this - I followed Dan's advice when changing my thermostat)

http://matt.zenfolio.com/xk-coolant-...tat---v1-1.pdf

Marc

 

I HAVE A 98 JAG XJ8L. I need to find out how to bleed the cooling sys.HELP