Hello, the previous owner of my RHD had removed AST and the coolant overflow bottle while leaving the stock radiator filler neck. I got a new OEM AST and want to connect it back as stock along with the overflow bottle. I would appreciate if I could get few closeup pictures of all the hoses and how they should be all connected. many thanks

 

 

Great picture, explains everything. thanks, could you please share an engine photo showing the mounting positions of AST and the overflow bottle? I think the AST must be mounted above the overflow tank and below the filler neck AST hose inlet, correct? A better question is a recommendation for mounting AST and overflow tank in a single turbo modded car?

 

Not my picture, just one from the net...assuming you still have the stock intercooler. Might be some other pictures/drawings in the Service Manual, and you’ll need a 10mm bolt and three (?) OEM spring clamps.
Also, IIRC, below the intercooler duct there’s a support bar which has one or two ‘U’ shaped plastic clips to route and retain the overflow hose. The hose is thin-walled so take care not to kink or pinch it when routing. Being soft and thin-walled is also why you want to use OEM clamps

 

I decided to stick with the removed AST setup. I will add a new 1.1 bar pressure cap with a built in thermostat and leave it the way it is. The top hose from the filler neck is connected to the overflow tank and this is connected to the bottom of the radiator. The lower filler neck inlet that goes to AST top nipple on a stock car is plugged. I attached a picture of my setup.

 

The silicone hose you are using with the bolt as a plug will likely fail. I would recommend looking that back to the nipple on the radiator with their an oem or reinforced hose or removing and welding the nipples shut. Samco also makes reinforced silicone caps if you want to go that route.

 

Thanks for the advise. Is it ok to use a piece of 5/8" fuel line again with the bolt and two clamps?

 

Plus 1 on changing out that unreinforced (vacuum) hose with the stuff recommended in the correct size that will take the heat.
And maybe it’s me but I’m not following you on the hose routing. Is the connection at the bottom of the radiator plugged? And a cap with an integrated t-stat? And I understand higher pressure-higher boiling point but that also adds (potentially) a bit more stress to the coolant seals doesn’t it? Unless it’s a single turbo thing .9 bar has always been fine for me.

 

The bottom drain on the radiator is plugged I checked it out. The blue silicon hose goes to the overflow bottle you see on the left. The cap is pressured at 1.1 bar. The stock cap is flat which requires AST installed. The car is a single HKS turbo with APEX'I ECU and a hand commander.

 

Hose size should be 3/8 for that but yes reinforced fuel line will work.

 

Where does the lower filler neck inlet (the one blocked off on my car) go to on a stock car? The ^^^ diagram doesn't show it.

 

Yes it is. To the upper (inlet) nipple of the AST.
What isn’t shown is the line going to the overflow tank...probably because that’s closed-loop.