Clive Randall running a 1994 80 series VX 4.2TD

[Clive A Randall]

Gents, I,m have an issue with my cooling system pressuring . I have had a new radiator fitted, new thermostat & water pump. I have had an exhaust gas test with positive results indicating there is no exhaust gases entering the water system, there are no visible water leaks , any thoughts would be most appreciated.

Thanks

Clive R

 

[StarCruiser]

Hi Clive and welcome.

Can you elaborate, what symptoms do you have that make you think your cooling system is over pressurising?

 

[Clive A Randall]

Hi Clive and welcome.

Can you elaborate, what symptoms do you have that make you think your cooling system is over pressurising?

Thanks for you quick response, the radiator pressures up & over flows into the system over flow tank adjacent to the radiator, could I be drawing air in at some point?

Clive r

 

[StarCruiser]

Thanks for you quick response, the radiator pressures up & over flows into the system over flow tank adjacent to the radiator, could I be drawing air in at some point?

Clive r

Does it do this continuously, so you lose water, steam etc. or is it the case that all is brim full and its losing expansion water?

 

[clivehorridge]

Hi Clive, we have at least two things in common, name and an 80 series, welcome to the forum

The overflow as you called it, is an expansion tank (as Rich correctly described it) and as the system heats up the pre-set pressure of the radiator cap allows (expansion) water into the plastic tank.

As the system cools, after stopping the engine, that water should be drawn back into the circulation of the main system.

Having, replaced the things you've listed, did you replace the radiator cap? If that's allowing water to pass into the expansion tank too freely, then it may overflow.

Is your problem violent, i.e. a boil up with scolding hot water, or is it just an overflow problem?

The expansion tank should stay about 1/2 full when it's cold. There's a line indicator in the plastic.

 

[Clive A Randall]

Does it do this continuously, so you lose water, steam etc. or is it the case that all is brim full and its losing expansion water?

Good "StarCruiser, I checked the amount retuned to the expansion tank which was in the region of one litre. A new radiator cap was fitted, the water does not return to the radiator, the remaining water in the radiator just covers the top of the vanes.

Clive R

 

[Clive A Randall]

Hi Clive, we have at least two things in common, name and an 80 series, welcome to the forum

The overflow as you called it, is an expansion tank (as Rich correctly described it) and as the system heats up the pre-set pressure of the radiator cap allows (expansion) water into the plastic tank.

As the system cools, after stopping the engine, that water should be drawn back into the circulation of the main system.

Having, replaced the things you've listed, did you replace the radiator cap? If that's allowing water to pass into the expansion tank too freely, then it may overflow.

Is your problem violent, i.e. a boil up with scolding hot water, or is it just an overflow problem?

The expansion tank should stay about 1/2 full when it's cold. There's a line indicator in the plastic.

Clive Good morning, as you see my post to Star Cruiser, a new radiator cap was fitted. My problem is not violet, it just appears to be an overflow problem. Also the water does not return to the expansion tank after the engine has been switched off

Clive R

 

[chadr]

Also the water does not return to the expansion tank after the engine has been switched off

Are you saying that you're losing coolant?

i.e. when the radiator is cold, you start with coolant in the expansion tank at the "cold" level, then after a engine cycle and when the radiator has become cold again, the expansion tank's level has gone down/below cold?

 

[Shayne]

Unless this problem was the reason you changed the rad i would put the old cap back on if only to eliminate the most obvious likely cause completely .

If there's a crack in the tubing from cap to the bottom of expansion tank it might fill up under pressure but suck air under vacuum leaving the coolant where it is .

 

[StarCruiser]

I've never in 12 years of ownership been able to keep any coolant in my expansion bottle on my 81. It has never missed a beat (vibrations aside) and has always kept the same level of coolant in the rad. Either this is normal or I've had an undiagnosed problem for 12 years.

 

[chadr]

The coolant level in my 90's system stays fairly constant - that is in the rad and tank and the expansion tank level goes up/down as expected with engine temp too.

I might need to top it up with 200-300ml of coolant every 5-6k miles or so. The 80s system can't be that different?

 

[clivehorridge]

Since the rad blew a 2" split in the top tank and was replaced with an OEM Rad, new thermostat and new rad cap, the coolant level has stayed on the line in the expansion tank.

Yes, it goes up and back down with hot and cold but at cold start, much to my amazement, it's consistently on the line.

 

[Clive A Randall]

Are you saying that you're losing coolant?

i.e. when the radiator is cold, you start with coolant in the expansion tank at the "cold" level, then after a engine cycle and when the radiator has become cold again, the expansion tank's level has gone down/below cold?

Morning Chadr, the level of the coolant in the expansion tank has increased, & does not return back into the radiator.

Clive R

 

[Clive A Randall]

Unless this problem was the reason you changed the rad i would put the old cap back on if only to eliminate the most obvious likely cause completely .

If there's a crack in the tubing from cap to the bottom of expansion tank it might fill up under pressure but suck air under vacuum leaving the coolant where it is .

Morning Shayne, many thanks, will recheck the tubing for cracks etc.

Clive R

 

[StarCruiser]

Morning Chadr, the level of the coolant in the expansion tank has increased, & does not return back into the radiator.

Clive R

Has it stabilised, or does it continue to fill the expansion bottle without you adding or removing coolant or removing/refitting the rad cap?

 

[Clive A Randall]

Has it stabilised, or does it continue to fill the expansion bottle without you adding or removing coolant or removing/refitting the rad cap?

I have carried out further checks again today, there are no cracks etc in the expansion bottle or tube. I have topped up the radiator & expansion tank to the correct levels, I shall recheck tomorrow after 200mile round trip tomorrow, & let you know the outcome.
Once again many thanks for all the info.

Clive R

 

[Clive A Randall]

Morning Chadr, the level of the coolant in the expansion tank has increased, & does not return back into the radiator.

Clive R

Morning all, I replaced the original radiator cap and have been monitoring radiator & expansion tank over the past few days, both appear now to be remaining steady, please accept my thanks for all the info supplied doubtless I shall be in touch over the next weeks or so with some other little issue/challenge once again many thanks

Clive R

 

[Shayne]

Glad your sorted Clive

I am sure it would be helpful to others if you could tell us who supplied your new radiator which was obviously sent out untested ?

 

[Clive A Randall]

Glad your sorted Clive

I am sure it would be helpful to others if you could tell us who supplied your new radiator which was obviously sent out untested ?

Hi Shayne, Roughtrax 4x4 supplied the radiator, I don't think I can put all the issues with my cooling problems with the Roughtrax radiator, some possibly down to of my inexperience in not initially checking the thermostat which was exceedingly stiff & would not budge until boiling water was poured on it, I replaced this with a genuine Toyota one & the combination of new radiator new thermostat & old radiator cap appears to have done the trick.

Thanks again.

Clive R