Coolant Reservoir Overflowing

[interested!]

Originally Posted by Wileyk24

Hi guys,

Just did a major tune up on my 87 supra turbo. Plugs, wires, air filter, fuel filter, valve cover gaskets, etc. I even replaced all the air and coolant hoses in the car. I went with the ebay silicone hose kit which has 26 hoses in it. Overall I am happy with the quality of the hoses, leapyears ahead of my 25 plus year old factory hoses(so please don't flame over the ebay purchase). My car is bone stock.

So, with everything finished, my car keeps spitting coolant out of the overflow bottle. I have no signs of overheating(temperature guage is steady, stays in the middle, and never goes high or bounces around). I got a block test kit and tested my engine twice, both times no signs of a BHG.

So I assume I have to burp the system. I have heard all about it. Problem is when I try to burp the system I am not getting any air bubbles, just coolant pulsing slowly up and down and coming out of the radiator cap(when the cap is off). First I tried burping the car on my car ramps. Then I tried jacking the car even higher with my floor jack. Neither way seems to produce any difference in effect. Even did all of the above with the heater on full blast just in case.

What should I do? Car drives great, no smoke from my tailpipe, I am stumped.

Kris

Hi! Had the same problem! found the solution by COLD pressure testing the radiator cap , found to be releasing pressure too early and continuing to zero . This can be done by making a 4 way adapter to :COLD pressurise system / check pressure / release pressure and removes bubbles , this can be put into top heater hose , please see pictures . cured by adding shim to rad cap at sealing ring to increase length . set to release at around 13 PSI ,should shut off at around 10 PSI .Check by putting the OVERFLOW PIPE into a container of water and pressurise system with a foot pump attached to the shrader valve and check for bubbles ( releasing pressure ) leave to settle and watch gauge for bubble stop ( containing pressure) .By COLD testing the cap can be removed and refitted quickly after releasing pressure .This can be left in place to generally check the system for leaks .

[interested!]

Originally Posted by interested!

Hi! Had the same problem! found the solution by COLD pressure testing the radiator cap , found to be releasing pressure too early and continuing to zero . This can be done by making a 4 way adapter to :COLD pressurise system / check pressure / release pressure and removes bubbles , this can be put into top heater hose , please see pictures . cured by adding shim to rad cap at sealing ring to increase length . set to release at around 13 PSI ,should shut off at around 10 PSI .Check by putting the OVERFLOW PIPE into a container of water and pressurise system with a foot pump attached to the shrader valve and check for bubbles ( releasing pressure ) leave to settle and watch gauge for bubble stop ( containing pressure) .By COLD testing the cap can be removed and refitted quickly after releasing pressure .This can be left in place to generally check the system for leaks .

Please see photo of shim position for message above. The small valve in the centre should be firm enough to contain pressure , BUT , weak enough to allow vacuum refilling of the system after shutdown - ensure all rubber seals are in good condition ( no nicks or wear grooves )

[Green7mgte]

rather spend 5 bucks and get a new cap. lol Nice mod tho.. +1

[interested!]

Originally Posted by Green7mgte

rather spend 5 bucks and get a new cap. lol Nice mod tho.. +1

Hi! Thanks for your reply , I had bought and tried 5 new caps over many years to try and cure this problem -losing fluid without overheating - before I took this course to eventually cure it , now I am confident that I have the problem " sorted " - no fluid loss and no overheating problems when driving for hours in hot weather either! , -my answer to , it seems , a common problem.

[Green7mgte]

Yea I had that problem once.. a new cap just solved it.. good mod if its recurring.

[Wileyk24]

Hey,

Thanks for the reply's. I have had a new development. I didn't have time to drain the radiator down a little to remove the hose and test the thermostat. So I just went ahead and purchased a new radiator cap instead. I installed it last night, drove the car to work for the first time this morning and just as I was pulling in to work my car started OVERHEATING!! It went up and came back down in less than a minute or so.

Again, the system is full of fresh fluid, no leaks, and even no reservoir overflow since I put on the new radiator cap. No oil in fluid, no smoke from the exhaust...

I am seriously hoping that the overheating issue is my thermostat otherwise I am in for some serious repair work in my future.

Thoughts?

Kris

[Green7mgte]

replace your thermostat.. perhaps look into a fail safe one.. were if it fails it just sticks open.. no overheat