Coolant flowing out of cap

amf201091

Member
Joined
Apr 23, 2020
Messages
103
Reaction score
46
Location
Omaha, Nebraska
So i have a 98' gt thats a dedicated track car. I put a mishimoto radiator along with a new t-stat not to long ago. It has a moroso expansion tank. Everytime when the car is hot and i spin out off track or come to a stop... coolant shoots out of my cap! Ive replaced the cap with a new one (16psi/1bar) from autozone but still does it. Any ideas on what i should do? 19psi cap? Am i overfilling expansion tank? Theres no level with moroso's so i only fill it about half way when cold... help! Lol
 

OpalFrostGT

Active Member
Joined
Oct 30, 2021
Messages
276
Reaction score
198
Location
Whitney,TX
I believe this is a simple thermal expansion problem. If Hot coolant is leaking past the 16 psi rated cap, get a new Ford 16 psi cap and a higher rated psi cap. That should stop the leak of Hot coolant at that specific point. BUT, be prepared to discover that the Hot coolant has found another place to leak! In my driving experience, most mechanics use 100% coolant...not the 50/50 blend coolant. This may solve the issue for you...but creates another potential issue of chemical damage from the coolant to exposed metals. Hope these thoughts help you.
 

OpalFrostGT

Active Member
Joined
Oct 30, 2021
Messages
276
Reaction score
198
Location
Whitney,TX
I just discovered a much higher pressure radiator cap...appears to be a quality product. $28.95. Multiple seals. Thermometer included in top of the cap appears to be functional. Rated for Max pressure of 1.8 BAR = 27.557 psi.
Brand: Outlaw
Hope this helps. Are your hoses a rubber blend material?
 

OpalFrostGT

Active Member
Joined
Oct 30, 2021
Messages
276
Reaction score
198
Location
Whitney,TX
Caution!!! I do NOT RECOMMEND using the Outlaw Racing website!
My security program detected a serious threat from their website!!!
 

OpalFrostGT

Active Member
Joined
Oct 30, 2021
Messages
276
Reaction score
198
Location
Whitney,TX
STANT also has a high pressure racing radiator cap...

Stant 10393 High Pressure Racing Radiator Cap, 28-32 Lbs​

Hope this helps you solve this issue!
 

OpalFrostGT

Active Member
Joined
Oct 30, 2021
Messages
276
Reaction score
198
Location
Whitney,TX
Moving beyond the Radiator Cap question, we should consider the Type of coolant you would benefit with...
A. You said this is a racinf application. Does the track allow EthYlene glycol based coolants? If NOT...consider a waterless coolant such as EVANS coolants. Www.evans oolant.com
They have a product: Npg for racing! $34.95 for 1/2 gallon! But, it might help solve your issues.
Also, are your hoses rubber or silicone? What about the clamps. IMO you just cannot go cheap in regards to the entire cooling system! It is the heart of your engine.
May I assume that you have a real temperature scale on the coolant temp gauge? If NOT, correct that issue.
my hope is that some of ghis information is going to help you solve this issue.
 

Latest posts

Forum statistics

Threads
76,270
Messages
1,473,384
Members
14,154
Latest member
NekRoass

Members online

Top