Coolant leak

[Remyd]

Good afternoon,

I found a leak from the part circled on the picture, is that the heater valve?
I recently had the dash semi out, by that I mean that the oil pressure/ temp valve was still attached to it while the dash was disconnected from the car. I presume that I must have put some tension on the cable attached to the valve.
The leak seems to come from underneath the circled part on the picture.
What is the part and is it easy to fix. I am supposed to take part in the MGCC spring run on Sunday and only have tonight (Thursday) and a few hours on Saturday afternoon to fix it. Is there a quick fix or do I need the part?

[10coupe]

Hi Remy,

It is the heater valve. Unfortunately you will most likely need to replace it.

It might be worth checking if the leak stops with your heater control knob in different positions - hot, warm and cold to see if it stops but with the distributor below the valve you don't want that getting wet so it's not worth letting it drip too long. It might be worth checking the hose connection just in case it's that leaking.

The heater valves are prone to failing so it's probably best to just change it as they usually cost under £20.

Hope you get it sorted
best Neal

[Remyd]

On closer inspection, the leak seems to come from the inside of the valve. turning the knob doesn't move the cable but doing by hand increase the or decrease the leak.
I have got a new valve on order, I'm hoping that it'll arrive by Saturday otherwise I can forget about the Spring run on Sunday!
I also noticed a lot of pink dried deposit by the hose.

[10coupe]

ah, definatey time to change - hope you get it sorted in time for your run.

The pink deposit is probably antifreeze splashed from the leak

[Charles Farran]

Hi Renny,
Before fitting the new valve, with the valve in the open position ,blow through it & then close the valve until it stops your breath going through. Mark that point on the body slot where the lever rests. Then ,when fitted to the block ,the cable should be fixed to match that point with the control in the off position on the dash. This saves wear on the heater valve which is one reason why they fail.
Cheers,
Charles

[Michael Barclay]

Hi Remy
As others have mentioned, this is the heater valve and is prone to failure. There Is a rubber diaphragm inside that perishes over time, causing the valve to leak. The valve sits above the distributor so could cause ignition problems if water drips into the distributor. Don’t forget to order the gasket when you order the valve.
You mention you have pink deposits around the valve. This suggests you have the red OAT (Organic Acid Technology) type antifreeze. This can damage to the water pump, radiator etc in an MGB. As you will need to drain some of the fluid off to fit the valve I would recommend draining completely and filling with the blue ethylene glycol.
Mike

[Paul Scott]

https://www.ebay.co.uk/itm/295579049943 ... 88QAvD_BwE

This chap manufactures these in the UK

https://www.facebook.com/profile.php?id=100064893151889

[Paul Hollingworth]

Mine leaks quite badly in the off position but doesn't so much when its fully on.

[Remyd]

So the new valve is on, no leakage.
Charles, I only just saw your post so didn't have the chance to take your advice. I got the car running in the garage without signs of major leaks, only a little sipage from the gasket but nothing major.
I took the car for a test around the estate. I had to park to give way to an oncoming bus, when I stopped the engine died and the ignition light came on.
I managed to get it going again but only for a few meters then it died again. Couldn't get it to fire. I left it for about 5 to 10 minutes while I was getting the warning triangle set up, I broke down near the local school at pick up time, and trying to find the number for the AA.
I got back in the car and turned the ignition on, the car started again. \Got back home safely.
Now, when the leak happened there was quite a lot of coolant dripping. There's a black grommet on top of the distributor which is quite loose so I am thinking that some of the coolant could have leaked inside.
Would it be wise to order a new distributor and fit it? Which one should I get? Mine doesn't look like it has points. How hard are they to fit and how do you know which HT lead go where on it?
Picture of the distributor for reference.

[Vic Butler]

Is there no manufacturer's name on the distributor? It looks like one of these all electronic versions which are unserviceable and it seems that water has got inside.
Unfortunately pattern part distributors are rubbish. Your best bet would be to find a used correct distributor and send it to the Distributor Doctor for reconditioning. I did that with both my MGB and Land Rover distributor. The MG has Lumenition Optronic ignition but the Land Rover has Pertronix fitted by the Doctor.
The easy way when swapping plug leads to a new distributor is to fit the distributor first leaving the plug leads attached to the cap of the old one. Fit the new cap to the distributor then with the caps in the same orientation swap the leads one at a time or simply number the leads before removal.