Tr4 expansion tank

[Richmac]

Could I also ask please is the TR4 radiator suitable for adding a normal expansion bottle too?

[Trumpy3]

Yes. The problem here in Australia is getting a 4PSI recovery radiator cap. Most use a 7PSI cap.

A good recovery system overcomes the need to remove the radiator cap to check the coolant, thus removing the stress on the top tank extension when removing the cap.

While not that important here, it does greatly reduce the dilution of the anti freeze by continually topping up the coolant.

Brian

[Don H.]

Should be no problem at all.  It was an original fitment back in the day.  My very late sidescreen TR3B had a TR4-style overflow bottle when I got it in 1981, and I fitted (and continue to use) a new one when I restored the car.

[Richmac]

Thanks guys I'll get one and put it on 

[Z320]

You can fit one, but it is not needed.

Just don’t overfill the rad, than you will not loose coolant.

On my TR4A (original with overlow bottle) it is always empty

Ciao, Marco

Edited June 1 by Z320

[stuart]

Early TR4 with the neck extension same as the earlier sidescreen cars already have an expansion tank, its the neck thats what its for, if you fill the rad so you can only just see water at the bottom of the neck when looking in the cap hole then thats correct.

Stuart.

[TR Rob]

And if you overfill, it just spits excess water out when hot, usually when parking and the coolant finds its own level….ask me how I know !!

[Z320]

I'm convinced they fittet the overflow bottle

to get rid of annoying complaints from annoying customers,

 who have fun with topping up the level and "loose" coolant.

[Richmac]

Thanks for all your replies guys really appreciate it 

[stuart]

1 hour ago, Z320 said:

I'm convinced they fittet the overflow bottle

to get rid of annoying complaints from annoying customers,

 who have fun with topping up the level and "loose" coolant.

Well not quite that, with the later cars from 4a on the rad doesnt have any room for expansion if filled to the neck which was always the thing people were advised to do back then , therefore water has no where to go other than out the overflow hence the introduction of the overflow bottle to allow for expansion and recovery.

Stuart.

[Z320]

44 minutes ago, stuart said:

Well not quite that, with the later cars from 4a on the rad doesnt have any room for expansion if filled to the neck which was always the thing people were advised to do back then , therefore water has no where to go other than out the overflow hence the introduction of the overflow bottle to allow for expansion and recovery.

Stuart.

It works well on my TR4A with the rad core only a few millimeter covered with coolant. 

[stuart]

3 minutes ago, Z320 said:

It works well on my TR4A with the rad core only a few millimeter covered with coolant. 

Yes because theres room enough for expansion then. People always fill to the neck though.

Stuart.

[BlueTR3A-5EKT]

No flexibility in the top hose between the moving engine and the rigid radiator?

Factory top hose drawing calls for more than 10° of available flex in the convoluted top hose.  
 

[RogerH]

22 hours ago, Richmac said:

Could I also ask please is the TR4 radiator suitable for adding a normal expansion bottle too?

Top hose should be more like this    HOSE

 

You are also missing the righthand rad steady

 

Roger

Edited June 1 by RogerH

[iain]

21 hours ago, stuart said:

Early TR4 with the neck extension same as the earlier sidescreen cars already have an expansion tank, its the neck thats what its for, if you fill the rad so you can only just see water at the bottom of the neck when looking in the cap hole then thats correct.

Stuart.

+1. You don’t need an expansion tank for the existing expansion tank…….

[Z320]

I consequently use the therm "overflow bottle" for this bottle on TRs, not "expansion bottle".

Because the coolant flows OUT of the locked cooling system, mixes with stored coolant that gets fresh oxygen and is sucked back in the old cast iron boiler.

This makes the rather original locked system to an opened system. Sadly Triumph made this a goodness on TR4A-TR6. IMO this is wrong.

"Expanion bottle" to me suggests a locked cooling system, which is the issue on modern cars. 

Just my opinion.

Ciao, Marco

Edited June 2 by Z320