Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Please help me understand my cooling system

I have a 1962 Plus 4 that was restored maybe 15-20 years ago as far as I can tell.
It's sat in a barn for last 5 years or so, and I've been working on getting it back on the road.

It runs very hot, and there appears to be a minor leak of coolant into the passenger footwell from the heater core.

Among other things, I've been trying to understand what was done to the cooling system, which is very much not original. The under bonnet area is warren of unkempt water hoses with T connections that I am struggling to understand.

The car has what I am assuming is a header/expansion tank mounted on the firewall that has a 7 lb cap. The radiator itself has no connection to this tank, and the radiator has what I assume is a blanking cap.

Here is a diagram of what I have seen under the bonnet:


My questions are:

1. Does this look reasonable at all? Would it be worth attempting to simplify it (if nothing else to make it a little less unsightly)? The T connections around the heater core don't make sense to me - it looks like there are multiple, parallel paths the coolant can take.

2. Where could I place a shutoff valve(s) to shut off the heater core? From what I have read online the 7 lb cap may be more than the heater core can take. Since this is a Sunday driver summer-only car I can afford to be without heat.

Any input or guidance you could provide me would be greatly appreciated! I am reasonably mechanically inclined but I grew up in the era of plugging my laptop into my car to diagnose it and make changes, so much of the grease-under-the-fingernails parts of this are new to me. I sense that I will have more than just cooling changes to make to get it to run cool, but I at least want to understand what I've got before I start chasing my tail.

If it is a TR derived engine the heater valve should be on the water outlet at the back of the head. The other heater pipe is the one from the pump.

Don't understand the rest of the plumbing, my expansion tank is fed from the small overflow pipe on the radiator neck, (which is open with a banking cap?) What has happened to your radiator overflow?

This video is stylised and fairly simple but the process is the same.
https://www.youtube.com/watch?v=V7inC4lOpGs

This should help - Morgan Parts Book Diagram

Heater valve can now be sourced here.

I added the expansion tank to my system (to make it more "modern") and it works well. Have photos of mine if you need them.

On a standard 62 +4 with a TR motor the cooling system is really pretty straight forward and didn't normally have any major overheating issues.
Basically the thermostat housing has the top hose for the rad and a bypass hose to the water pump where the bottom hose also comes in from the bottom of the rad. On the back of the water pump housing is the return from the heater.
The heater is fed from a screw in valve on the top of the cylinder head (available at Melvyn Rutters).
That is the simple standard system . It should be fine with the 7lb cap on the rad and an overflow pipe from just below the cap. The heater obviously needs a repair.
The mod to have the expansion tank requires you to lead the overflow pipe from the rad to the body of the Exp tank and also have an overflow from that tank to waste. The pressure cap then goes on the expansion tank and the sealing cap on the radiator.
If there is still major overheating after that then either the rad is blocked, thermostat stuck closed or water pump knackered.
Sorry I don't have any pictures but there are pictures of engine compartments on the web in for sale ads.
Cheers

The front end of the cooling system will be quite standard , as outlined by Broljo above.

It is the back end of your system that is non standard and needs a total rethink.

I think you should separate the 2 problems, if you have water inside the car then you have a leak , either from the heater matrix (most likely) or hoses. Sort this first.

Once that is done I would run the inlet to the heater from the back of the head (as above. and the return is a single pipe on the opposite side of the head back to the pump.

Those both being done , now run a small bore pipe from the radiator filler overflow pipe to a catch tank and mount this either on the scuttle or the vertical face of the bulkhead. This can have a simple low pressure cap, and put a simple sealing cap on the radiator (as above).

That system worked well on my +4 race car and you don't need any more than that.

As above if overheating is still present, then look at the common causes of this, head gasket, liners crudded up inside the block, stuck thermostat, blocked or damaged radiator , slipping fan belt , ineffective water pump etc

Thank you all for the replies. It turns out that I accidentally omitted a line from my diagram. My car DOES have a line running from the radiator directly to the expansion tank.

I am still puzzled by the T junctions that are set into the lines to and from the heater core that also go to the expansion tank. It sounds like those are not needed. I wonder what the intention was in running them...

I have added two additional photos that show more or less the complete system.

Not shown are the fact that the radiator inlet and outlet fittings are at the top and bottom on the same side of the radiator, I guess that means this is an aftermarket cross-flow radiator? also not shown is the electric fan mounted in front of the radiator. Ideally this would be behind as it blocks a substantial amount of airflow through the radiator.

Is this a lowline (4/4 body)car?

Erm were are the return lines from pump to engine?

From that I get the impression the coolant goes to the pump and never returns to the block therefore no cooled water returning to cool down the engine.

I confess I do not know how to tell the difference. Here it is: