Australian Jensen Forums

For owners of Jensen Cars from Australia and around the world.

Radiator coolant level

Get your motor running...

by stephenw » Tue Aug 23, 2016 3:27 am

When charging the radiator with coolant, the manual states, that the coolant should be charged to 32mm below the filler neck seat. On the added diagram which position is considered the filler neck seat. Position A or Position B.
Posts: 94
Joined: Wed Jul 25, 2012 9:40 am

by Paulio » Tue Aug 23, 2016 7:49 am

I would've said "A" for the possibility that the filler neck seat would be where the cap seal "seats" and seals on the top???
Happy to stand corrected...
User avatar
Posts: 121
Joined: Thu Feb 17, 2011 12:59 pm
Location: Melbourne

by stephenw » Tue Aug 23, 2016 10:20 am

Thanks Paulio
Well i was thinking position B, as the the seat of the neck would be the base of the neck but then if I'm filling 32mm below position B then there would be just a shallow line of water in the pipe feeding the radiator when at correct level. That would also be with a closed thermostat preventing back fill into the engine block. What is the situation if the thermostat is permanently open which i think is the case for me as there is water flow on start up, would this mean I'm filling too much as the level would include whatever flows back into the engine block past the usually closed position of the thermostat. I'm still scratching my head on that one. Any other offers on position A.
Posts: 94
Joined: Wed Jul 25, 2012 9:40 am

by dinofritz » Tue Aug 23, 2016 11:30 am


I wouldn't overthink things for this - just put in the extra amount of fluid, and it would overflow into the expansion tank if needed.

I fill up from the fuller neck location, warm up the car until the thermostat opens to bleed out any air from the system, and when it starts to overflow slightly from the filler neck, then I add the cap to seal the system.

Cheers, Dino
User avatar
Posts: 81
Joined: Wed Nov 16, 2011 2:08 pm

by stephenw » Wed Aug 24, 2016 6:26 am

Your quite right, i have a tendency to overthink the simple things. The expansion tank is quite big and will take whatever isn't able to sit in the system whilst hot.
Thanks Steve
Posts: 94
Joined: Wed Jul 25, 2012 9:40 am

Return to Mechanical


Who is online

Users browsing this forum: No registered users and 1 guest

View new posts