Coolant tank replacement query

[Steve Tinker]

Potty......
Changed mine last year and depending how supple or what tools you have makes a difference.
The removal is not difficult (I used 101 Projects for your Boxster manual) as you can loosen the old tank and pull it forward to loosen the connection hoses.
The installation is somewhat more difficult. Lots of people in the US buy the special tool that can remotely open / close the steel springs that retains the coolant pipes. Nowhere in Australia had anyone even heard of these tools, so I had to use pliars to remove the original clamps & then reinstall with screw type S/S clamps.
The only way I could push on the hoses and hold the clamps to tighten was from the bottom which means you have to remove the 2 x diagonal cross members and alloy plate under the gearbox. This was the knuckle grazing, sweat inducing part which took over an hour in 35 deg C temps just to connect the pipework.
Some people can get the clamps / pipes on from the boot (trunk), but I couldn't get enough play on the pipes to accomplish this.
Notes:
1) Be carefull with the oil filler and dipstick pipes - they become brittle with age & break easily.
2) You have to drill out the new coolant tank where the dipstick goes through - 20mm hole I think.
3) It may be a good time to check all the other coolant componants (pump, T.stat, coolant, drive belt etc) while the system is empty.
4) A helper is advantageous when replacing the pipework.
5) It took me over 5 hours to install & fill with coolant, but if I were to do it again with the right tool, maybe half that time.

[pothole]

Originally Posted by Steve Tinker

The only way I could push on the hoses and hold the clamps to tighten was from the bottom which means you have to remove the 2 x diagonal cross members and alloy plate under the gearbox. This was the knuckle grazing, sweat inducing part which took over an hour in 35 deg C temps just to connect the pipework.
Some people can get the clamps / pipes on from the boot (trunk), but I couldn't get enough play on the pipes to accomplish this.

This is what is confusing me.

From another thread here, one guy removed three pipes from inside the trunk/boot connecting the the tank to the feed-through plate, attaching them to the new tank as he went along:





I'm struggling to understand why you would disconnect them from inside the engine compartment. From what I can see, there's only one that you must deal with from inside the engine compartment. But obviously I haven't done the job yet. But am just confused by apparently contradicting advice that variously says you need to get underneath, you can do it all from the top, you need to drain all the coolant, you just drain the tank, you disconnect all the pipes in the engine compartment, you only disconnect one pipe inside the engine compartment.