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Coolant line issues.

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Kdouglas89

Proven Member
436
11
Jul 8, 2013
Davenport, Iowa
Last summer I replaced just about every coolant line. They were over pressurizing and popping around the clamp point. I am starting to get the same issues as before, and can not figure out why. I thought I might have been tightening to much, and they would expand and break. I tried loosening a bit, but they would just leak because of looseness.

I have burped the system multiple times with the heat on, and trying to squeeze all air out of top and bottom rad hoses.

Any help would be appreciated.
 
What will the radiator cap do?

It increases the boiling point of your cooling system by raising the pressure inside the system. A 50/50 mixture of ethylene glycol antifreeze and water normally boils at 227 degrees F.; with 4 lbs. of cap pressure, the boiling point goes up to 239 degrees F.; with 7 lbs. of pressure it rises to 248 degrees F.; and with 14 lbs. of pressure it is increased to 263 degrees F.

The cap also uses a pressure relief valve that prevents a dangerous buildup of internal pressure within the cooling system. When an engine is shut off, a heat soak period follows during which pressure can build within the cooling system. The cap vents this pressure by allowing a small amount of coolant to overflow the radiator into the coolant reservoir. This prevents damage to the engine and the more vulnerable cooling system components such as the radiator, heater core, hoses and water pump seal, while preventing the loss of coolant that escapes from the radiator.

It's also a vacuum relief/siphon valve. As the engine cools, the coolant inside the radiator and engine, along with any vapor pockets that may have formed, begins to contract. This creates a vacuum within the cooling system. The vacuum relief function of the cap allows coolant to be siphoned from the reservoir back into the radiator to maintain the proper coolant level.

So yeah, it's pretty important. ;)
 
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If your getting pressure building quick you could have a head gasket issue. The best thing to do would be to pressure test the cooling system and see what happens. How old are radiator and water pump?
 
If your getting pressure building quick you could have a head gasket issue. The best thing to do would be to pressure test the cooing system and see what happens. How old are radiator and water pump?

I actually just had a new motor put in last month. Radiator was last summer when I was having cooling issues, and Its a brand new water pump. I am fairly certain its not the head.

Edit : In one spot where its leaking now, it wont start till I am driving for awhile. It won't build up that much pressure from idle'ing. Lines wont get bloated. I have to replace a hose now, but it's just a small dip currently.
 
HowStuffWorks "How does a radiator cap work?"

I'm my experiences, the pressure being high would cause an overheat because it allows the coolant to boil at a higher temperature.

thats actually bass ackwards. running a higher pressure cooling system with the same components will HELP cooling, AND keep the water from boiling if it does get too hot.

common trick on closed stock class racing is to grab a replacement radiator cap with a higher PSI rating then stock.


as for the problem, either there is air ,or oil maybe, getting into the system from somewhere. or the hoses are not seating properly, have you tried new clamps a long with new hoses?
 
Sounds like you just have air getting in the system and screwing things. Replace the bad line and refill system and let it sit idling for awhile with the cap off. It also helps to squeeze the hoses ever now and then to help the ati move out. I would still pressure test the system and make sure it will hold but also to make sure there arnt anymore leaks!
 
as for the problem, either there is air ,or oil maybe, getting into the system from somewhere. or the hoses are not seating properly, have you tried new clamps a long with new hoses?

I have not tried new clamps, and I have replaced hoses.

Question : Should coolant lines be experiencing so much pressure that they bloat up in size? I have never had an issue with top, and bottom hose. Just the small ones surrounding the thermostat area.

Question 2: Would it be worth it to invest $50-75 on one of those ebay silicone kits?
 
Just because the motor is new doesn't mean the HG can't be leaky! Do a compression test and rule it out! Old lines will bloat also oil soaked lines will to. And replacing with silicone doesn't seem like it will change anything, I would figure out the issue first.
 
the ebay silicone hose kits are actually pretty nice. make absolutely sure that where the hoses atach it is 100% clean. and if i haven't mentioned this before, get new clamps, especially if you go with the silicone hose kit.

is it always the same hose that pops? or always one of the small hoses? to the throttle body? locating an area would allow you to run water through that specific chamber and see if it is clogged.

Just because the motor is new doesn't mean the HG can't be leaky! Do a compression test and rule it out! Old lines will bloat also oil soaked lines will to. And replacing with silicone doesn't seem like it will change anything, I would figure out the issue first.

this also, new lines and clamps are great, old clamps may be a problem. but so might a head gasket. you have some trouble shooting to do before calling it complete.
 
Just because the motor is new doesn't mean the HG can't be leaky! Do a compression test and rule it out! Old lines will bloat also oil soaked lines will to. And replacing with silicone doesn't seem like it will change anything, I would figure out the issue first.

I should have done this when I bought the motor, but every cylinder except the 3rd from the left is at about 160. The 3rd is at 145-150ish. Those were testing without it on wide open throttle, so id imagine they would look a little bit better.

"3rd cylinder kinda makes me nervous". :hmm:
 
if your a lucky man pull the valve cover and add some torque to the head bolts. (they are torque to yeild on all except fairly early 1gs) so do this VERY carefully. it wont fix a ruined head gasket but it may cure a weeping head gasket.

otherwise headgaskets and headstuds. (studs are not required but its cheap insurance.)

have you ever found any black residue or rainbow colors in the coolant? if its getting to be warm in your area purge the coolant system with a garden hose then fill it with pure distilled water and drive the car like that for a while. then you can drain it into a clean pan and see if it is getting contaminated and maybe by what.
 
have you ever found any black residue or rainbow colors in the coolant? if its getting to be warm in your area purge the coolant system with a garden hose then fill it with pure distilled water and drive the car like that for a while. then you can drain it into a clean pan and see if it is getting contaminated and maybe by what.

No, I inspect the coolant quite often and it has not looked dark at all. I have no smoke coming from exhaust, and I am not really showing any other sign of head gasket issues. My car is not over heating.

I think I will flush the system, and run distilled water to be sure though.
 
I would try another cap before doing anything. Just because it is newer doesn't mean that it isn't defective. Even if the head gasket is pushing pressure into the cooling system it will be regulated by the cap.
 
Your right o.p, new hoses def should not be bloating and you may want to have your cars coolant "sniffed" with a special analyzer. It can quick tell you if exhaust gases are getting in the coolant. If not I would suspect a possible restriction of some sort causing higher than normal pressures. You could maybe tap in to a line and read pressure.
 
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