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Michael Paceskoski
Experienced User
Username: forever_elegant

Post Number: 36
Registered: 7-2005
Posted on Saturday, 24 September, 2016 - 07:07 pm:   Edit PostDelete PostView Post/Check IP

Just wanted to update everyone on my progress and maybe someone might have some valuable thoughts to share.

after starting the vehicle for the first time in many years i noticed that the water temp gauge was working. i embarked on cleaning up the cooling system and these are the things i have done so far.

-cleaned up water sensor terminals and threads, tested in boiling water and change in resistance, which passed the test. Does anyone know the resistance range for the sensor.

-removed thermostat with tool, cleaned from scale, tested in boiling water and opens fully to about 7mm just before water is boiling. thermostat is 76'C opening.

-back flushed radiator 10min, from bottom hose. clear water

-back flushed from both engine block taps out through lower water pump and thermostat for about 10min. clear water

-Ran car for about 10 15 min without thermostat, temp increased only slightly, but this was a test if the water pump was working. water circulating through top rad hose only at a higher rpm. Is this normal?

-Drained water, was very dirty at this point. Im thinking that the heat is breaking up scale and grime/crud. Has anyone ran a cleaning agent through the system to aid breakdown of scale successfully?

-Re-fitted thermostat and ran car for 10-15mins. car came close to normal temp and thermostat seemed to open. What is the normal time that thermostat will open in stationary position with light throttle?

-will drain and repeat above process until i get mostly clear running water.

-Im planning on running green Nulon coolant at 50:50 ration with water. any other coolant brand or type suggestions?

any suggestions guys will be greatly appreciated?
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David Hughes
Frequent User
Username: wedcar

Post Number: 61
Registered: 7-2004
Posted on Sunday, 25 September, 2016 - 08:34 pm:   Edit PostDelete PostView Post/Check IP

This link was posted on the American RR website regarding cooling water system cleaning.
It suggests fill the system using 1lb (.5KG) of citric acid per 1 gallon (5 litres)water then run the car for half an hour, then flush the system with water.
I have not had to use this myself however there are quite a few comments about the success of this treatment.
Trust that helps.
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Michael Paceskoski
Experienced User
Username: forever_elegant

Post Number: 37
Registered: 7-2005
Posted on Sunday, 25 September, 2016 - 09:26 pm:   Edit PostDelete PostView Post/Check IP

Thanks David,

Iv just applied to register for the US RROC forum and ill have a look at the link when Its activated
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David Balfour
Experienced User
Username: sidchrome

Post Number: 27
Registered: 2-2009
Posted on Monday, 26 September, 2016 - 10:06 am:   Edit PostDelete PostView Post/Check IP

Hi Michael I have two thoughts on this. The first is any corrosion on the outside of the wet liners, and the second is corrosion of the aluminium alloy. A product like Evap-O-Rust will dissolve the wet liner rust completely into solution without introducing acids/alkalis to the cooling circuit which are not so kind to the rubber components particularly. They also produce a product for aluminium oxide, but I don't know anything about it.

The brilliant thing about the wet liners is that they transfer enormous amounts of thermal energy to the water jacket, and thus keeping them rust/scale free is critical. I've also heard when they do rust that corrosion can build up between the liner and the block in places where the clearance is in the mm region, putting lateral pressure on the liner and leading to liner distortion and possible mechanical engine damage.

On the maintenance side, an older club member told me he knew a guy that used to drain his cooling system annually and add dish washing liquid, run the engine until hot and then drain, flush and refill with coolant. He says his was the cleanest cooling system he ever saw on a car.

I gave the Evap-O-Rust advice to a former club member who had a chronic overheating problem with his Spirit. He bought and filled his cooling system with the ordinary stuff, they make one just for cooling systems too. After a drop in operating temperature progressively over 4 days, he drained and flushed the cooling system. I expected him to tell me the drained solution had turned black (was yellow when added), because as the iron ions bond to ions in solution, the carbon from the rust is liberated sending the mixture black. He said it looked like brown mud, which possibly suggests that as the rust formed, dirt and contaminants in solution was captured and held by the rust. In any case he was deliriously happy with the result, as no amount of chemical flushing/cleaning to that point had helped.

The manufacturer claims Evap-O-Rust is non toxic, neutral pH, and harmless to rubber base metals etc., which is important for our cars. I believe there may be at least one other similar brand of chelating solution on the market - start googling.

As for the alloy, I'm sure the citric acid will help clean that as does phosphoric acid. In any case, it would be wise to clean all prior to adding your inhibitor. Don't forget to make sure your heater taps are open, if they work, so you clean out the heater core(s) at the same time.
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christopher carnley
Unregistered guest
Posted From:
Posted on Tuesday, 27 September, 2016 - 02:48 am:   Edit PostDelete PostView Post/Check IP

Evap-O-Rust conains EDTA a chelating agent with a very long name. It has a ph of 6.1 and as an organic acetate, is mildly acidic.
It is used as a chelating agent by injection to precipitate lead and other heavy metals principally from the blood of workers employed in such trades.
It is also used to "rejuvenate" lead acid batteries.

(Message approved by david_gore)

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