Hello everyone,
So i have 92 SC400 and i absolutely love it, but i faced problem which i can't think out what is causing it.

My old radiator was leaking coolant, in my country it is nearly impossible to find brand new or used radiator for SC. So i bought Aluminium GS radiator which is thicker, and it has own cap, made custom mountings for it and hydraulic ventilator (will add pictures on sunday)

As GS radiator is thicker i couldn't fit in my old expansion reservoir so i tried to run it without reservoir. I blocked that small hose (which went to reservoir near top radiator hose) with bolt and metal strap (talked to guy who turboed his 1uz, he said he blocked that hose aswell).

So i drove it for couple of miles and i checked under the hood, coolant was spilling out trough radiator cap.

I bought aluminium reservoir(350ml) bolted it in, made everything so it could work.

Drove it for couple of miles and it seemed to work, but today after driving for 30min in city, after i parked the car, i poped the hood to check if everything is allright, i saw that it pouring coolant trough reservoir cap hose.

What could cause the problem? Because with stock radiator and reservoir it worked fine. Maybe head gasket is blown? I made sure there is no air in the system.

Maybe someone has ideas.

And if there is already a thread about it sorry

Thanks

(will add some pictures on sunday, atm i can't because i'm working)

 

I've never quite understood the early SC400's radiator/reservoir system, but it's pressurized in some atypical fashion that makes replacing components difficult. That sounds like what you're dealing with. I would start with reading up on how that aspect is supposed to work, and see if you can backtrack the changes you made to closer resemble it.

 

It's very possible your system is filled with tons of air and needs to be bleeded out.

 

Ill try to bleed it out one more time.

 

Just start the car and open up the radiator cap . Let it idle for 10-15 minutes.

 

On the SC300 there is a heater control valve; not sure if the same part is used on the SC400 but when it fails it can cause pressure build up........ Not a cheap part, either, as there are no after market alternatives. Some have bypassed it altogether but then no heat inside the vehicle.

Do a search to get some information......

 

But if heater control valve doesn't work I should not be able to control my interior heating temperature. It should always be hot or cold.
In my case i can control temperature.