: the water pump gasket you will get from EB Spares will be a paper type one, supplied with the pump. The Alfa part is a thin steel one at about GBP9
. The gasket that sits on the pump and underneath the "square" housing is also "paper" in the EB Spares water pump but as stated the Alfa part is steel with upturned "wings" projecting out the side. These steel gaskets are a revision to Alfa's original specification. FWIW, I've used the EB Spares gaskets and there's no problem.
Both the 24V Super and the 24V QV are both 12 litres (source: official supplement to the owner's manual, 1993/4 model year). You won't be able to drain it all unless you can get at the bottom radiator hose (mine was rusted solid), the front engine block drain (under the exhaust manifold - easy to reach from below, 22mm hex head) and the rear engine block drain (impossible to see, feel even for a double jointed midget so don't bother). The block doesn't actually retain that much - but I didn't actually measure it as it p155ed all over me when the plug came right out. You probably won't want to try to drain the whole heater either. There's no way a 24V is going to be under 10 litres on partial refill I'd say.
Heat it very slowly
(a big pan with loads of water helps and tie a string oir wire round it so you can turn/lift it if needed). Get a thermometer to look for the temp it starts to op-en and the fully open temperature. Starts to open at 87°C ±2°C and fully open at 99°C. Max opening is 7.5mm. Sounds like yours is opening but is it soon enough?
Same on the 24V 3lire QV and Super AFAIK. You are right about the intake runners/hoses.
Drop the water out again - as much as you can from the rad and the front block drain. I filled on level ground through the expansion tank filler - very slowly
to allow air not to become trapped. I had the thermostat off until the water was visible in the hole, then fitted the themostat and continued, very slowly again until coolant came out the vent hole on the stat. Fitted plug. Carried on until cooland was just into the expansion tank followed with plenty of squeezing of hoses looking for coolant to drop and replenishing as I went.
Added moderate amount of coolant to expansion tank and started engine with filler cap off. Didn't seem to have any prob even as engine got hot so turned off engine, topped up coolant and it's been OK. All this rather as Lexio has already advised.
If top of rad. and top hose isn't getting really hot but the stat works, you possibly don't have enough water in the system.
Like others here, I've not heard of the impeller failing but I suppose it could be spinning on its shaft.
Bigger bolts exactly where? This is probably not the cause of your problem but is a bit worrying. The three bolts down through the stat are the rather odd size of M7. They frequently corrode in and then break off when you try to remove them... If yours are M8 then that's likely to be what's happened.
Interested to know how all this turns out. Hope this helps but fear it may not...
When you finally get it sorted don't forget fill with 50% Paraflu (expensive but good), 50% distilled water.