Notices
86-95 Trucks & 4Runners 2nd/3rd gen pickups, and 1st/2nd gen 4Runners with IFS

cooling system overpressurization

Old 07-29-2014, 11:08 AM
  #1  
Registered User
Thread Starter
 
Turbopickup24's Avatar
 
Join Date: May 2014
Posts: 66
Likes: 0
Received 0 Likes on 0 Posts
cooling system overpressurization

Im having this problem. In the morning the up and lower radiator hoses are rock hard on cold start in till engine reaches 190℉ then they soften to normal and its cause my radiator to leak when cold.
And this is a 1991 pickup 3vze new all aluminum radiator new hoses new water pump fresh coolant. And Tstat that has 10,000 miles on it

Last edited by Turbopickup24; 07-29-2014 at 11:10 AM.
Old 07-29-2014, 11:30 AM
  #2  
Registered User
iTrader: (1)
 
JasonYota's Avatar
 
Join Date: Mar 2013
Location: Mobile, Alabama
Posts: 2,121
Likes: 0
Received 0 Likes on 0 Posts
What about your radiator cap?
Old 07-29-2014, 12:11 PM
  #3  
Registered User
Thread Starter
 
Turbopickup24's Avatar
 
Join Date: May 2014
Posts: 66
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by JasonYota
What about your radiator cap?
Its Brandnew not more than 2 weeks old
Old 07-29-2014, 12:11 PM
  #4  
Registered User
Thread Starter
 
Turbopickup24's Avatar
 
Join Date: May 2014
Posts: 66
Likes: 0
Received 0 Likes on 0 Posts
What pressure cap should i have
Old 07-29-2014, 12:33 PM
  #5  
Registered User
iTrader: (1)
 
JasonYota's Avatar
 
Join Date: Mar 2013
Location: Mobile, Alabama
Posts: 2,121
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by Turbopickup24
What pressure cap should i have
I believe a standard is 13psi. What's strange is it's building pressure after it's cooled off
Old 07-29-2014, 12:37 PM
  #6  
Registered User
Thread Starter
 
Turbopickup24's Avatar
 
Join Date: May 2014
Posts: 66
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by JasonYota
I believe a standard is 13psi. What's strange is it's building pressure after it's cooled off
Because the cap that came with radiator say 15-18psi i dont understand either could the pump be creating to much pressure. While the tstat is closed
Old 07-29-2014, 01:37 PM
  #7  
Registered User
iTrader: (1)
 
JasonYota's Avatar
 
Join Date: Mar 2013
Location: Mobile, Alabama
Posts: 2,121
Likes: 0
Received 0 Likes on 0 Posts
Try taking the cap off in the morning when it's cooled off. It sounds like the system is holding pressure.
Old 07-29-2014, 01:51 PM
  #8  
Registered User
Thread Starter
 
Turbopickup24's Avatar
 
Join Date: May 2014
Posts: 66
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by JasonYota
Try taking the cap off in the morning when it's cooled off. It sounds like the system is holding pressure.
How do you fix it if its holding pressure what causes it to do that.
Old 07-29-2014, 05:26 PM
  #9  
Registered User
iTrader: (1)
 
JasonYota's Avatar
 
Join Date: Mar 2013
Location: Mobile, Alabama
Posts: 2,121
Likes: 0
Received 0 Likes on 0 Posts
Verify that's it's building pressure when you take the cap off the pressure should release. This is the first I've heard of a cooling system build pressure with the engine off. Pressure builds with heat.
Old 07-29-2014, 08:32 PM
  #10  
Registered User
 
abecedarian's Avatar
 
Join Date: Mar 2008
Location: Temecula Valley, CA
Posts: 12,723
Likes: 0
Received 4 Likes on 4 Posts
It should, when warm, vent pressure and coolant to recovery tank, then suck the coolant back in as it cools off.


If it's building pressure up when cold starting, I'd suspect a head gasket issue that 'fixes' itself once warmed up and things 'expand'.
Old 07-29-2014, 11:34 PM
  #11  
Registered User
Thread Starter
 
Turbopickup24's Avatar
 
Join Date: May 2014
Posts: 66
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by abecedarian
It should, when warm, vent pressure and coolant to recovery tank, then suck the coolant back in as it cools off.


If it's building pressure up when cold starting, I'd suspect a head gasket issue that 'fixes' itself once warmed up and things 'expand'.
I let it cool while at work and before i pulled the cap i felt the hose and it was super soft and ran it till it warmed up with cap off and it did fine. Added the cap and it slowly built pressure to normal. I think it cool and pulls coolant in and doesnt let it exspand into exspansion tank when its hot causing a over full cooling system. Ill get some block tester tomaro. And test the coolant for exhaust gases and pickup a radiator cap

Last edited by Turbopickup24; 07-29-2014 at 11:40 PM.
Old 03-03-2016, 10:53 AM
  #12  
Registered User
 
dwj7386's Avatar
 
Join Date: Dec 2013
Posts: 2
Likes: 0
Received 0 Likes on 0 Posts
idle control valve clogged

possible solutions: wrong psi rad cap (should be 13psi), thermostat is wrong temp (should be 180), head bolts need to be retorqued



disregard title due to post in wrong thread.

Last edited by dwj7386; 03-03-2016 at 11:42 AM. Reason: possible solutions
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Ktm526
84-85 Trucks & 4Runners
2
10-07-2015 05:14 AM
Rickstwowheels
Newbie Tech Section
6
09-09-2015 06:12 PM
shalom
Engines - Transmissions
2
09-08-2015 10:02 PM
some drunk guy
86-95 Trucks & 4Runners
4
09-04-2015 11:55 PM
128keaton
86-95 Trucks & 4Runners
6
09-03-2015 05:09 PM


Thread Tools
Search this Thread
Quick Reply: cooling system overpressurization



All times are GMT -8. The time now is 12:47 AM.