So some context.
My 1988 Ford Escort's coolant expansion tank cracked not long ago, genuine Ford tanks are rare and expensive.
( It's a pressurised tank, with the inlet hose coming from the thermostat housing, and the outlet on the bottom going straight into the lower rad hose and water pump.
So i ordered an aftermarket one, installed it, everything seems ok, let the engine bleed the air out on its own with the cap off ( no bleed screws ), coolant right on the max line as it should be.
Then i decide to take it on a long ~60 mile drive each way to the beach, about half of the way into the trip ( driving on the highway at a normal 60-70mph the temp gauge starts creeping up, i pull over at a gas station and the engine is definetly hot but i open the cap on the tank and there is no pressure at all ( there should be ).
I let the engine idle until the temp gauge goes back down to about the middle, where it should be.
The rest of the trip i decided on getting off the highway and making my way there on a normal country road, the engine did not overheat and stayed at a normal temp.
On the way back home about 6 hours later i did the same thing and again hot home fine.
Then i noticed the cap doesn't seem to fit quite right, if you tighten it too much, it goes loose.
( plastic tank and cap )
So i returned the tank and they sent me another one.
This time the cap seems to fit better and close right, but still after driving for about an hour the engine starts getting too hot.
I don't understand where the pressure is going, if the cap fits right.
With the engine hot if you open the cap you should hear a clear "pssshhhhh" of the pressure escaping, it doesn't have even a little pressure.
Hope you can give me some new ideas because i don't know what to do, other than scour ebay for a genuine new old stock one that costs 150 bucks, or buy a nasty old used one.
By the way, the coolant is very clean and the water pump was replaced 2 years ago, it has never had any overheating problems before...
My 1988 Ford Escort's coolant expansion tank cracked not long ago, genuine Ford tanks are rare and expensive.
( It's a pressurised tank, with the inlet hose coming from the thermostat housing, and the outlet on the bottom going straight into the lower rad hose and water pump.
So i ordered an aftermarket one, installed it, everything seems ok, let the engine bleed the air out on its own with the cap off ( no bleed screws ), coolant right on the max line as it should be.
Then i decide to take it on a long ~60 mile drive each way to the beach, about half of the way into the trip ( driving on the highway at a normal 60-70mph the temp gauge starts creeping up, i pull over at a gas station and the engine is definetly hot but i open the cap on the tank and there is no pressure at all ( there should be ).
I let the engine idle until the temp gauge goes back down to about the middle, where it should be.
The rest of the trip i decided on getting off the highway and making my way there on a normal country road, the engine did not overheat and stayed at a normal temp.
On the way back home about 6 hours later i did the same thing and again hot home fine.
Then i noticed the cap doesn't seem to fit quite right, if you tighten it too much, it goes loose.
( plastic tank and cap )
So i returned the tank and they sent me another one.
This time the cap seems to fit better and close right, but still after driving for about an hour the engine starts getting too hot.
I don't understand where the pressure is going, if the cap fits right.
With the engine hot if you open the cap you should hear a clear "pssshhhhh" of the pressure escaping, it doesn't have even a little pressure.
Hope you can give me some new ideas because i don't know what to do, other than scour ebay for a genuine new old stock one that costs 150 bucks, or buy a nasty old used one.
By the way, the coolant is very clean and the water pump was replaced 2 years ago, it has never had any overheating problems before...