Supra Heating/Cooling System!!

I have seen a lot of threads about people with possible heater matrix problems and airlocks. Can someone a bit technical help me understand how the system works?? I have recently had a leak and had a couple of pipes replaced, the heaters weren't brilliant before but when the car came back from the garage the heaters were crap. They had filled the system through the radiator..!!

I work in the domestic/commercial heating industry and I am confused as to how the header/expansion sytsem works. It seems that the header/expansion tank is not at the highest point of the system. How can an airlock possibly be removed form the system if there is no positive pressure to force it out. Is it expected that the water pump will do this job?

I now have an airlock in the pipes at the highest point of the system near the bulk head. I broke the pipes recently and there was no coolant in there at all. I filled the pipes and re-attached them losing a small amount of coolant but this made the heaters inside the car inprove.....

I have tried to park the car on a slope and remove the rad cap but this didn't solve the problem until I actually filled the pipes manually! I am thinking about fitting a small valve/T piece into this pipe then I can manually purge the air from the highest point!

Surely when Toyota designed the system it worked well!

The pipe is where the green screw driver is resting!!

http://img301.imageshack.us/img301/20/pict1130wx8.jpg

Surely my street has a big enough slope!

http://img301.imageshack.us/img301/628/pict1131hh9.jpg

Any help would be appreciated but I am going to try this and see if it fixes my heater problem. I am satisfied that the matrix is not blocked due to the massive improvement by removing most of the airlock!

H.

Streets not slopey enough H. More slope more pressure. Damn good idea with the purge valve though. If you fit that, would you do a guide?????

Less slope leave longer. But if you have a pipe or whatever that' sat at a higher pressure it'll never clear anyway.

Your idea sounds ace.

So the more of a slope is trying to get the system level then and therefore forcing the air out. Sitting a t-piece would be easy. I just need to find a small valve/cap that where you can top up the system and then seal the system.

I am going to nip back to the plumbers merchants where I used to work and see if I can get some small bits and bobs!!

H.

Nice. Would a Schraeder valve do it as in the AC system.???

And if I haven't done so already... Merry Christmas to you, Mrs H and the littluns.

If you put a funnel in the radiator filler and fill it with water/coolant until it backs up the funnel. Then you can pinch and squeeze the rad hoses and hoses that go to the turbos and squeeze all the bubbles out. its amazing how much air is in there sometimes after you think its full. Also make sure the header tank is full. The theory behind that is that as the coolant chills and contracts it is sucked out of the tank and into the system.

If you put a funnel in the radiator filler and fill it with water/coolant until it backs up the funnel. Then you can pinch and squeeze the rad hoses and hoses that go to the turbos and squeeze all the bubbles out. its amazing how much air is in there sometimes after you think its full. Also make sure the header tank is full. The theory behind that is that as the coolant chills and contracts it is sucked out of the tank and into the system.

Nice. Copied, saved.

Nice. Would a Schraeder valve do it as in the AC system.???

 

And if I haven't done so already... Merry Christmas to you, Mrs H and the littluns.

Cheers AndyT and the same to you mate!!

A Schraeder valve would not be what I was looking at. Just a basic pipe and cap arrangement to fill the system from the back instead of the radiator!!

H.

H what is the thing with the bracket attached to the passenger side suspension top mount? the bit that has the big tube going across to the intake...........

the bleed valve is a very interesting idea mate if you go ahead with it i would love to see pics of the modifcation

i parked my motor on a hill just as steep when i did my coolant last week

i filled the rad, started the engine (with rad cap off) and squeezed the pipe with the green screwy on and had a few bubbles come out, have you gave that a try i was abit if`y about doing that coz every coolant system ive played with was pressureized and was always told not to do it, but all i did was play with the pipes squeezing them all and made sure i got as near to 9 ltrs in as possible

A bunch of guys do this with the mk3 supra as it has the same damn problem.

any links or extra info ?

Ive done this with no joy, made my own valve and fitted it here arrowed in green.

H what is the thing with the bracket attached to the passenger side suspension top mount? the bit that has the big tube going across to the intake...........

Thats the vapouriser to the LPG. The pipe is then linked to the air intake. I don't understand how it all works tbh!!

 

i filled the rad, started the engine (with rad cap off) and squeezed the pipe with the green screwy on and had a few bubbles come out, have you gave that a try i was abit if`y about doing that coz every coolant system ive played with was pressureized and was always told not to do it, but all i did was play with the pipes squeezing them all and made sure i got as near to 9 ltrs in as possible

I squeezed the pipes Steve but the level of coolant in the top of the rad just came up and flowed out of the top and down the radiator. It just seens like the bubble doesn't want to shift. I went on a decent run after that but I haven't checked the coolant level yesterday!

H.

get a POL injector and take some out then and then try and shift the bubble that way?

my blowers didnt blow hot till iwent down a hill so i think that must have shifted the bubble if there was one there

get a POL injector and take some out then and then try and shift the bubble that way?

my blowers didnt blow hot till iwent down a hill so i think that must have shifted the bubble if there was one there

What is a POL injector??

I am going to try a couple of things ie the bottle in the top of the radiator to create some false head on the system.

I think the filling valve on the rear of the engine will work but lets see. Nothing to be lost really, if it doesn't help I will just take it out and try something else!!

H.

a POL injector is just a big syringe to suck up some of the coolant it might help to take some out of the rad then try and fill it again

Having tried it, I think the JZA80 is a pain in the ass to bleed. I had to take the pipes off of the heater matrix, shove a funnel down each, pour coolant down the funnel whilst holding it at a raised position, then (quickly!) remove the funnel and reconnect the matrix pipes. I inherently dislike any procedure where you have to do something very quickly.

Some people advise parking on a slope and bleeding air out of the rad cap, but that's not practical if you don't have any slopes within 'coolant-getting-hot' distance of your home. I've tried the upturned Powerade bottle in the rad filler cap to provide a raised reservoir, but I couldn't get a decent seal between the rad and bottle. For this to work with the standard rad, you might need to fabricate a header reservoir incorporating with a rubber bung.

Is it more of a pain getting airlocks out the existing radiator/heater matrix or a new one? I'm planning on getting an after market rad and thought this thread helps - not sure if there might be some helpful tips that can help you??? http://www.mkivsupra.net/vbb/showthread.php?t=83646

Some people advise parking on a slope and bleeding air out of the rad cap, but that's not practical if you don't have any slopes within 'coolant-getting-hot' distance of your home. I've tried the upturned Powerade bottle in the rad filler cap to provide a raised reservoir, but I couldn't get a decent seal between the rad and bottle. For this to work with the standard rad, you might need to fabricate a header reservoir incorporating with a rubber bung.

I found that a plastic funnel with a tapered end worked perfectly.

I used a robinsons 1L Bottle and some electrical tape. Worked well althou I only filled it about 4 or 5 inchs up and my heating is still bobbins. Out of interest, how hight did you other guys fill?

I used a robinsons 1L Bottle and some electrical tape. Worked well althou I only filled it about 4 or 5 inchs up and my heating is still bobbins. Out of interest, how hight did you other guys fill?

I gave up with the bottle in the rad filler trick. I just filled it SLOWLY using the rad filler (with no home-brew header tank), and then filled the heater matrix pipes directly.

I think the problems come when the heater matrix is getting a little clogged up. My guess is that it makes the matrix more susceptible to trapping some air.

Mine has a new rad and a new heater matrix, flushed the coolant system through 3 times but still have a lame heater, if i have the fan on the slowest setting i get hot air which slowly reduces in temp as you raise the fan speed.

Mine has a new rad and a new heater matrix, flushed the coolant system through 3 times but still have a lame heater, if i have the fan on the slowest setting i get hot air which slowly reduces in temp as you raise the fan speed.

Mine does exactly that too! It's as if a moderate or faster fan speed is too fast for the trickle of warm air coming out of the vents. It all points to an inefficient matrix methinks.

Exactly how did you flush the matrix? With hose water? If so, how long did you push hose water through the matrix for? 5 mins? 10mins? And with what pressure?

Mine does exactly that too! It's as if a moderate or faster fan speed is too fast for the trickle of warm air coming out of the vents. It all points to an inefficient matrix methinks.

 

Exactly how did you flush the matrix? With hose water? If so, how long did you push hose water through the matrix for? 5 mins? 10mins? And with what pressure?

I just put a hose on the inlet to the matrix with the outlet disconnected and carefully opened the tap, didnt go mad though !

Got a good flow through with no signs of crud or anything other than clean water coming out.

I doubt it was five minutes but i'd already drained and flushed the system when fitting new rad and new matrix, i also fitted a new thermostat and heater ecu as well.

Thanks for the info chap. It should help others (including me) with the same problem.