Curious if any of you Jag experts can explain to me why there is a Plastic section of hose in-between two sections of larger rubber hose on each end of the bleed hose running from T-stat housing to the Expansion tank??
I was re-installing the engine covers and the dang plastic pipe just snapped. Of course the part has to be ordered so I took a piece of 3/8 ID radiator hose and made the mend. Seems to me this is all that is needed. Why the plastic that easily becomes brittle and breaks?? Anyone?? Trying to decide if I should order the OEM part.

 

Probably because it’s thinner and looks better than having a rubber hose running on top of the engine. The accountants are probably the ones who chose plastic instead of a metal line.

 

As I understand the workings of our system: The coolant expands as it heats up and is relieved thru the overflow tube. When the system cools a vacuum is created and the previous overflow is sucked back into the system.
Plastic isn't used because it costs less or looks good, it is a material that can withstand a vacuum, where as a rubber hose collapses under vacuum and blocks flow back to the system.
Check out www.SNGBarratt.com and download a free parts catalog and replace it with the correct part.

 

I've previously used 1/4 inch copper tube as an emergency fix ........

........... and that's why.

Graham

 

I have replaced this stupid hose/pipe 2 times on my car in 10 years. Basically, if I have to remove it, I buy another and just expect it to break.

 

Good to know its not just me.