Radiator overflow

[Longgone]

I`ve noticed many times just as my thermostat opens the radiator will overflow coolant. This doesn`t happen every time nor does it matter whether the radiator is topped off or down to the cooling fins. I believe the thermostat is a 185*. Any ideas?

 

[7demon2]

could it be the thermostat is sticking? if it is starting to stick closed then i would imagine that when it did open it would be hot enough to overflow some till it cooled back down....just my 2 cents if you don't know the age of the thermostat then you might want to replace it. go with a 180...

 

[Mrmopartech]

Make sure that the level of the rad is just above the cores when the cap is off cold.This will allow the expansion of the coolant and not force its way out into the over flow tube or resovoir.If you do not have a catch can,it pours on to the ground,not cool.Buy leaving the coolant level above the cores this will give you the needed area for expansion,mrmopartech

 

[krabysniper]

You don't have a catch can, do you?

 

[cavemanmoron]

You don't have a catch can, do you?

Heck I am using a 16 oz gatorade bottle;
held by an extra long cable tie.

I cut a hole in the top of the cap, for the overflow hose to go in,
and the hose goes to the bottom of the bottle.

It passed NHRA inspection. ;)

 

[Longgone]

No catch can here! This car was made before the government protected people or the environment. I`ve tried different fluid levels and that doesn`t seem to make any difference, I think I`ll give the thermostat a go. It`s only maybe a year old but it may have been crap out of the box. We`ll see.

 

[THWrench]

Check your cap!

 

[340mopar]

Heck I am using a 16 oz gatorade bottle;
held by an extra long cable tie.

I cut a hole in the top of the cap, for the overflow hose to go in,
and the hose goes to the bottom of the bottle.

It passed NHRA inspection. ;)

If you switch to a Powerade bottle it is worth 5hp... LOL

 

[krabysniper]

I didn't think u had a catch can. If you put one in, you will find a lot of your problems with this particular issue will disappear. I didn't have one either and I had a simialar problem, put a catch can in and problem gone. I used a catch bottle from a 73 Satelite and used my hot rodding inginuity to make a spot for it where the old carbon cannister used to go. You can kinda see it in this pic, it allows your coolant to expand and contract and yet keep the cooling system as full as possible at all times for best cooling capabilities. It is a worthwhile investment in time and effort. Cost for me was $0

 

[Longgone]

I`m going to install an overflow bottle, for the birds and bees if nothing else , and see if that helps. The cap and thermostat both checked out OK.Thanks guys.

 

[redfastback]

what is the cap rating? 13, 16? I like 13 myself. for every pound of pressure, it raises the temp 3-5 deg and the boiling point. it sounds like you may need more lbs in the cap. a cooling system pressuretest will be the best thing to do. if you are changing it, put in a radcap. best money ever spent as well as controlling electrolysis.