Super Dexta overheating

[Steph-a-knee]

I recently aquired a Fordson Dexta which had been standing in a barn for about 25 years. Amongst other things the water pump needed replacing and I also changed the thermostat at the same time. When I ran it the other day the temperature guage soon went up into the red and it started to overheat. When I felt the hoses, the top one was cold and the bottom one was hot. Coolant started to come out of the overflow from the radiator and when I took off the cap the coolant was cold. The only reason I can think of for this is that the thermostat has failed, (and yes I did put it in the right way up) but before I go and take it all apart again does anyone have any suggestions as to what the problem could be? Thanks in advance.

 

[agrimax]

I'd think the radiator is probably blocked internally.

 

[tomlad]

Or summin blocked some were

 

[agrimax]

summin?

 

[br jones]

Remove the stat ,hose out engine and rad ,run plenty of water thru it all ,check pipes for being squeashed etc ,run without stat for a while ,see what happens,probaly sludge in the bottom of radiator

 

[tomlad]

If its been laid up , mouse nest in core or block ?? Were all hoses intact

 

[Steph-a-knee]

I'd think the radiator is probably blocked internally.

I don't think it can be blocked. Before we put it back together we ran a hose pipe through it for what seemed like half an hour or so and ran water through the engine block as well. Water was flowing through them quite freely.

 

[Steph-a-knee]

If its been laid up , mouse nest in core or block ?? Were all hoses intact

It's been washed through and all hoses were ok.

 

[Steph-a-knee]

Remove the stat ,hose out engine and rad ,run plenty of water thru it all ,check pipes for being squeashed etc ,run without stat for a while ,see what happens,probaly sludge in the bottom of radiator

Hoses are all new and not squashed and it was all washed through before new pump was fitted. When you say run without stat, do I take it out and put hose back on and fill with water? I suppose if the stat is coming out I should test it in boiling water just in case it's faulty before running engine without it?

 

[davidroberts30]

Head gasket gone

 

[Steph-a-knee]

Head gasket gone

How do I tell if it is?

 

[davidroberts30]

Know anyone with a MOT exhaust tester?put the probe in the rad cap and test for hydrocarbons

But pushing cold water out sounds like theres combustion gasses getting into the water

 

[Rusty_Relics]

I've just done the hoses and a coolant change on our super dexta.
it sounds to me like it's air locked.
check rad is full and run it with the rad cap off until the thermostat opens and you get full circulation. Squeeze the hoses to get the air out as it's running. Mind your fingers in the fan when squeezing the bottom hose !
When doing a coolant change I always flush block and rad as already mentioned here in prior posts.
while you are running the engine with rad cap off look for bubbles to indicate a blown head gasket,
(i.e, compression blowing into coolant)or a film of oil (rainbow effect) floating on the coolant. Also to check if head gasket has gone, check engine oil hasn't turned milky.

Hope this helps and you get sorted
Thanks,
Carl Hargreaves

here is my super dexta to give you some inspiration ?

 

[startinghandle]

When I fitted new thermostat to my
Dexta some time ago I drilled small hole as there was no jiggleing pin
Also I fitted the new stat in a certain way to avoid blocking bypass hose
I don't know about the super dexta but the cooling system in the ordinary
Dexta is non pressureised

 

[FonterraFarmer]

As startinghandle said, but also be aware that new thermostats can be faulty too.?

 

[Mursal]

Pull the stat out, run? After that with such a simple system, head gasket or a tight spot? A sniff test from your local motor factor will help identify, combustion gases in the coolant. Unless you have a giddy temp gauge?

 

[tomlad]

Id be supprised if My new cap from agriline held much pressure
All ok with system
Mate had megga problems with over heating on a home built screen, i thought it was engine tbh , huge rad off whatever, blowing/ pumping coolant out , i thought head .
New rad of agriline for major, 4 cylander engine , ford . Mended, crap rad must have bin restricted.

 

[Rusty_Relics]

Id be supprised if My new cap from agriline held much pressure

4Lbs or 7Lbs pressure there are 2 options that fit.
I have seen the scalding someone got from opening one of these on a MF 35.
if you think about it your rear tyre on a dexta operates at 12-14 Lbs.

 

[tomlad]

The cap they supplied was crap was my point

Cap i took off said oil on it , oil filling cap i think

 

[MrNoo]

As startinghandle said, but also be aware that new thermostats can be faulty too.?

This is common, my main ploughing tractor ploughed all season with a faulty stat, bottom hose never even got warm. Ended up (once I realized) taking it out and put in some boiling water, it would open a very small amount so just cut the centre of the stat out and been fine ever since. You'd think in this day and age they could make a decent working stat but i guess produced cheap and cheerful in some exotic far away place for peanuts.