Collapsed vacuum canister... what happened?

OEM vacuum pump?

 

It's the vacuum reservoir for the AC system flap motion system (so that there's a high vacuum always available to move the ACflow direction flaps around regardless of what the engine is doing) -- item 44 here:

https://www.ricambiamerica.com/car-diagrams/ferrari/v12/testarossa-group/testarossa-1990/air-conditioning-system.html

As long as it is not punctured, you probably wouldn't notice any AC operational problem (even though its internal volume is reduced some in that collapsed state). My guess would be there is some corrosion going on inside that weakened its structure. If it did/does have a hole in it, it wouldn't have any effect at all on the engine performance, but your AC flap system wouldn't work.

 

It almost is . The circular ribbing features (and the end caps) are designed so that even if the pressure inside goes to a complete vacuum, it still shouldn't implode. Another possibility might be that it inadvertently got "dented" during a previous service. Its ability to resist collapsing under vacuum is very dependent on its symmetric shape so even a small local dent can greatly reduce it resistance to collapsing -- just a thought...

 

Fascinating. I notice than in today's cars, when you ask the HVAC to change mode (say from DEF to dash vents), the system slows down the blower motor while the stepper motors (as opposed to vacuum motors) affect the requested change, so that the stepper motors, their gears and the vents' pivot points don't have to fight the pressure/higher airflow of the blower. The mode change is completed and the control unit restores the fan speed to where it was before you asked for a change. All this progress was iterative from your vacuum canister, which was probably pretty slick in the 1960's. Sorry for the ramble. John

 

you may try to put some airpressure into this canister, may be it will blow up right again? but be carefull. try first only with 0,1 bar and raise to max. 1 bar. put the canister into water when you try this. so if it will explode not much will happen. when you do this it is on your own risk and I´m not responsible

 

Here is one for sale on Ebay.

https://www.ebay.com/itm/Ferrari-Mondial-Testarossa-Air-Tank-61642700-65942900/122016877862?epid=1773917190&hash=item1c68c5cd26:g:1vMAAOSw3YNXYcxj

 

These coffee cans were on almost all US production cars in the 70s and universal replacements are readily available. Since that one is hidden , you could source one with two vacuum ports from any parts house and it should do the job. In fact this one has a striking resemblance to the one on my 78 Ford F 150. Seriously.

 

Thats cheap

 

Worst case I'll hide a modern unit in my oem. I don't feel comfortable buying a used vacuum canister just to stay original.[/QUOTE]

That might be a statement you will regret in a few years. Stay original at any "manageable risk" is my advise. In a few years you could be digging holes in the ground searching for the correct canister. Your own unit is definitely toast and will never be operational again in my opinion.

Best regards

Peter