Technical Facelift thermostat replacement ‘66 Pop drain questions

[Derbyfella]

Right back on the car with a view to selling now as Mrs has new Rockstar

Noticed that there is orange crusty fluid round base of thermostat so obviously starting to leak. Looks like battery tray has been out before…. There is no liner - retaining nut that you reach through the tray isn’t there, two little threaded bolts on the side of the ‘ECU’ are missing all of which I don’t really give a chuff about.

The big question is do I have to drain the whole system down for this?
It looks like the leak is the small pipe from the thermostat ie plastic connector.
Can I just remove top pipe from radiator. (Thermostat or radiator end)
I hated removing bottom connection from radiator before. Although bumper is off at the moment
Lastly how much fluid is in the system? More than 2 litres?
I have a basin but I’ve just used it for gearbox oil catcher -albeit cleaned afterwards

I have done this before but I had bottom hose off

Also the single use hose clips - are these easier to remove with a hose clip tool? Halfords hose clips are just jubilee clips

 

[John202020]

No need to fully drain
System holds about 7L
Just remove the small pipe from thermostat to drain enough, then the large

 

[Derbyfella]

No need to fully drain
System holds about 7L
Just remove the small pipe from thermostat to drain enough, then the large

Brilliant thank you!

 

[The Panda Nut]

Right back on the car with a view to selling now as Mrs has new Rockstar

Noticed that there is orange crusty fluid round base of thermostat so obviously starting to leak. Looks like battery tray has been out before…. There is no liner - retaining nut that you reach through the tray isn’t there, two little threaded bolts on the side of the ‘ECU’ are missing all of which I don’t really give a chuff about.

The big question is do I have to drain the whole system down for this?
It looks like the leak is the small pipe from the thermostat ie plastic connector.
Can I just remove top pipe from radiator. (Thermostat or radiator end)
I hated removing bottom connection from radiator before. Although bumper is off at the moment
Lastly how much fluid is in the system? More than 2 litres?
I have a basin but I’ve just used it for gearbox oil catcher -albeit cleaned afterwards

I have done this before but I had bottom hose off

Also the single use hose clips - are these easier to remove with a hose clip tool? Halfords hose clips are just jubilee clips

I would replace the ECU bolts any vibration won't do it much good. Easy to drop. ClickR pliers remove the hose clips but access to all of them is poor. The quick release couplings on the the lower hose never seal again in my experience, so best left alone anyway as they are only supplied with a new hose.

 

[Derbyfella]

Plastic connector in thermostat/small hose was damaged and broke off completely. I’ve bought Jubilee clips. The real pig to get off was the electrical connector, just didn’t want to move and I was trying very hard not to break it - eventually got some grips on it and it came off quite easily.

 

[steveras57]

Its one of the most common problems listed in my guide! thankfully aftermarket replacements with a metal pipe are readerly available ,I found one of the most difficult things was getting the remains of the broken pipe out of the hose!

 

[jrkitching]

The big question is do I have to drain the whole system down for this?

No.

You only need to lower it below the level of the thermostat housing.

The easiest way is to syphon it out using a piece of tubing. No need to disturb any hose connections (apart from the one on the thermostat) and no risk of breaking any of them or introducing new leaks. Plus you can put the coolant back once the job is done, so no need to buy any coolant either.

 

[steveras57]

if you have a road near you with a steep angle! say a hill at about 45 degrees you can park with the front of the car at the high point so the coolant runs to the back away from the thermostat housing that will help also aids re-filling and bleeding the system if needed when replacing coolant!.

 

[Derbyfella]

So currently all fitted…..I’ve got about 500ml of coolant to return into system but car still currently on one axle stand.
The missing tiny ECU bolts, any ideas what size or where I can get just a couple?

 

[John202020]

So currently all fitted…..I’ve got about 500ml of coolant to return into system but car still currently on one axle stand.
The missing tiny ECU bolts, any ideas what size or where I can get just a couple?

Ebay for bolts or Toolstation at a total guess 4 or 5mm metric fine you can buy 10 stainless ones cheaply not sure how many steel ones are the minimum at Toolstation

 

[Derbyfella]

Next worry.
Car front end is still off although wheels back on and now down off axle stands. I’ve run car up to temperature had heating on, but I know there is less coolant in car than before however still showing max in tank. Coolant level in tank doesn’t change….largely due to a small spillage there is another 4-500ml in a bottle, Large hose to radiator gets hot car doesn’t overheat but coolant level isn’t dropping….haven’t moved car yet…..

 

[The Panda Nut]

My experience has been that it needs using and topping up several / many times. Mine ran for a week then dropped the level a lot, needing another litre. Some say they self bleed I find they are difficult. Persevere. Good luck.