A while ago I had a question about plumbing a 4age silvertop. I am still confused. I now have:
* Side of engine to top of radiatior (32mm hose).
* Front of engine (on the side of thermostat) to bottom of radiator (32mm hose).
* Front of engine (top on thermostat) to top of expansion tank (16mm hose).
* Front of engine (on thermostat 2nd exit) is closed.
* Bottom of expansion tank to bottom of radiator (16mm hose).

Is this correct or have I done something wrong here?

Thanks...

Not sure of the 4age but most thermostats output water to the top of the radiator.
The expansion bottle should have the larger hose (usually at the bottom of the expansion bottle) to the bottom radiator hose and the smaller hose from the top of the expansion bottle to a high point in your water system. This is usually after the thermostat and before the radiator.

Except Toyota have mostly worked opposite to the majority and have the thermostat on the return from the radiator.

[Edited on 6/3/07 by bimbleuk]

Then it is the same as the K-series?
Because of my radiator being further away from my 1.4 K-series, I have removed my stat and replaced it with a thermostat housing on the output.
This prevents engine shock and has stabilised fluctuating temps.
Anyway, my original comments still apply with the toyota connections.
I should also have said that it is strange that your hoses from the expansion bottle are both the same size.
What you are looking for is a "trickle" of water through the bottle without reducing the flow through the main rad/engine.
I am using a 13-14mm pipe on the lower hose and a 6mm pipe from the top hose on the bottle. Because of these two connections, the system fills quickly and the air is removed.
As my bottle is clear, I can see the water flow out of the small hose in the top of the bottle.
Incidently, I have a spare thermostat housing for a K-series on ebay here< br /> It has a 30mm OD for hoses.

this might help a little....
Rescued attachment 4agwater.gif

No that piccie is of a 16v RWD AE86 engine, and is uncomparble to a 20V silvertops plumpbing.

anyway No piccies helas my website crashed. but here goes.

The Big tube on the back of the head is Bottom radiator.
The Big tube on the exhaust side of the head is Top Radiator.

The 2 Heater in/outlets on the back of the head need to be interconnected using a T piece, and on the 3rd side of the T the bottom of the expensiontank is connected.

The top outlet ,small tube, of the radiator (If there is one) is connected to the top of the expension tank, (Not the overflow tube on the expensiontank)

easy to do it this way. If you completly block the heatercore tubes you will get a hotspot around cyl 4 exhaust side, I don't know why, but a lot of headgaskets have gone for this reason. I know Raw mostly doesn't do this but mine has it, and it runs 4 to 5 degrees cooler than a friends silvertop that doesn't, also my temp is dead constant and his is not. toyota uses a bypass system around the core in the japanese toyota Levin, so it's supossed to be connected.

good luck

grtz Thomas

[Edited on 25/2/07 by thomas4age]

sorry didnt see that it was a silvertop. my bad

Thanks...

My radiator has a big (32mm) and a small outlet on the bottom (16mm), can I connect the bottom radiator outlet to the bottom of the expansion tank and the heater inlet/oulet to the top of the expansion tank?

Yes and No,

You can put the bottom tank to the 16mm bottom rad, but don't put the heater in/outlets to the top of the tank. you'll be then effectivly pumping water through the tank, and take away it's function.

the top out/in of the tank is to self-deair the water system from the highest point in it, or any point that might get an airlock, ie the top of the rad in my application because it;s tilted backwards.

if you do what you said, it can end up in the expensiontak being full of water and the air somewhere in the head or radiator
if there's no provision for the deair tube on the rad you can make one the top rad hose at it's higghest point or elsewhere.

grtz Thomas

[Edited on 26/2/07 by thomas4age]

This picture may help on the 20V 4AGE plumbing.

On my rad I just have a bleed nipple at the highest point. no return to the expansion tank. The water connection from the back of the water pump is plumbed straight back in the block as Toyota supplied it.


Silvertop 4AGE 20V, coolant plumbing