What pressure should my cooling system be able to hold? I think its 18 but am not 100% sure on that. Yep, I've got another coolant leak. Pretty sure its radiator
Cooling System Pressure
- Thread starter MrBClark
- Start date
Rubicon John
TJ Enthusiast
Because i pressurized my system to 18 and the radiator and other things started to leak. Wasn't sure if I pressurized it too much. Also, i hooked up the pressure tester to my jeep, let out all the pressure and started my Jeep. Let my Jeep run for about 15 minutes. Only ever built 7 lbs of pressure. That normal?
Rubicon John
TJ Enthusiast
Nope, it sounds like you need to replace whatever leaked with pressure on it. Then drain and if possible flush the cooling system with distilled water. Then refill and bleed the cooling system with a 50/50 mix of coolant, we recommend Zerex G-05
So I found two leaks. One was a rad hose and the other was the radiator itself. Going to replace the radiator and water pump while I am in there. Already did thermostat. This better fix the issue. Because I already changed the head with a TUPY one and the head gasget. Those better not be the issue. Or I will drive my jeep off a cliff.
Rubicon John
TJ Enthusiast
I should have mentioned to pressure test it before you get it going again. You can do it before you fill it, it might just take a long time to pressurize it if you’re using a hand pump.
I did pressure test it when it was cold. That's when the leak is worst. What i was saying was I put the pressure tester on, and turned on the vehicle. Just to see what it would build on its own. Probably not how it works but just wanted to see. But I did test it when it was cold, and found a leak
Hey guys, I realize this thread is 3 years old but I've recently found myself in a very similar situation. Last week while driving home from work the plastic top on my radiator cracked and coolant shot out all over the place. Was completely unexpected as the Jeep was running perfectly.
My cracked radiator is gone and in its place, is a fresh OE reproduction unit which is cooling and holding coolant just fine.
HOWEVER I all of a sudden now have an intermittent leak coming from my water pump. Is there anything in the coolant system that might cause excessive pressure other than a bad head gasket, and do so intermittently?
The reason that I say "other than a bad head gasket" is that I’m not seeing any other signs of a bad head gasket.
Obviously the first thing I checked was that. The radiator itself and all the connections to it were fine. So I just assumed that what looked like a leak was probably just left over coolant pooled in hidden corners of the engine compartment which was now being blown around by the fan. But then after about a 5 minute test run in the garage mostly at idle speed I noticed the leak was getting progressively worse. So I shut the engine off.
What followed was 20 minutes of my soul leaving my body while I frantically google searched "head gasket failure symptoms"
After the panic attack subsided, I restarted the Jeep and ran it at idle speed to see if I could pinpoint the leak. To my surprise the leak was gone.
So with great hesitation and skepticism I once again convinced myself that it MUST have just been the left over coolant that had previously shot out the top of my old radiator like a geyser last week. I then proceeded to take the Jeep for a 15 minute test drive at both city and highway speeds. I nervously came back, parked the Jeep running in the garage and looked underneath...No leak! So I shut it down and took a sigh of relief.
But then when I restart the engine 20 minutes or so later, the leak came back as the engine approached running temperature. That's when I was able to finally dive in and track the leak to the bottom of the water pump. But this left me scratching my head because I just replace the water pump along with the thermostat and thermostat housing only about six months ago. Not because anyone of them was particularly bad. I was just part of a really satisfying preventative maintenance kick I was on.
So, is there any way that a bad water pump could cause excessive pressure resulting in a radiator failure like mine? Or.
Could a blocked radiator cause excessive pressure resulting in it's own failure and in the proses damage the water pump and/or its gasket? Or.
Could some other component of the cooling system have caused the the radiator to crack under pressure and now the water pump and or it's gasket have become the next weakest link? Or.
Are my bro-science head gasket diagnostics misinformed?
I have a big camping trip lined up for the end of this month, and I'm really gonna be bummed if I have to bail on it.
I'm gonna to spam this across all the forums and groups and hope for the best. God help me. And I'm not even religious...
My cracked radiator is gone and in its place, is a fresh OE reproduction unit which is cooling and holding coolant just fine.
HOWEVER I all of a sudden now have an intermittent leak coming from my water pump. Is there anything in the coolant system that might cause excessive pressure other than a bad head gasket, and do so intermittently?
The reason that I say "other than a bad head gasket" is that I’m not seeing any other signs of a bad head gasket.
- No bubbles and or exhaust fumes present in the inlet of my radiator while the Jeep is idling with the cap off.
- No milkiness to the oil on my dipstick or on the bottom of my oil filler cap. I check with the engine both cold and hot.
- No white smoke coming from my tailpipe.
- No engine temperature fluctuations during idling or driving.
- No loss in engine performance. Jeep runs like a top.
Obviously the first thing I checked was that. The radiator itself and all the connections to it were fine. So I just assumed that what looked like a leak was probably just left over coolant pooled in hidden corners of the engine compartment which was now being blown around by the fan. But then after about a 5 minute test run in the garage mostly at idle speed I noticed the leak was getting progressively worse. So I shut the engine off.
What followed was 20 minutes of my soul leaving my body while I frantically google searched "head gasket failure symptoms"
After the panic attack subsided, I restarted the Jeep and ran it at idle speed to see if I could pinpoint the leak. To my surprise the leak was gone.
So with great hesitation and skepticism I once again convinced myself that it MUST have just been the left over coolant that had previously shot out the top of my old radiator like a geyser last week. I then proceeded to take the Jeep for a 15 minute test drive at both city and highway speeds. I nervously came back, parked the Jeep running in the garage and looked underneath...No leak! So I shut it down and took a sigh of relief.
But then when I restart the engine 20 minutes or so later, the leak came back as the engine approached running temperature. That's when I was able to finally dive in and track the leak to the bottom of the water pump. But this left me scratching my head because I just replace the water pump along with the thermostat and thermostat housing only about six months ago. Not because anyone of them was particularly bad. I was just part of a really satisfying preventative maintenance kick I was on.
So, is there any way that a bad water pump could cause excessive pressure resulting in a radiator failure like mine? Or.
Could a blocked radiator cause excessive pressure resulting in it's own failure and in the proses damage the water pump and/or its gasket? Or.
Could some other component of the cooling system have caused the the radiator to crack under pressure and now the water pump and or it's gasket have become the next weakest link? Or.
Are my bro-science head gasket diagnostics misinformed?
I have a big camping trip lined up for the end of this month, and I'm really gonna be bummed if I have to bail on it.
I'm gonna to spam this across all the forums and groups and hope for the best. God help me. And I'm not even religious...
I'd throw a $25 Napa water pump at it and see what happens.
Others would argue for a Mopar one but the $125 plus cost is too rich for my blood.
Might want to do your tensioner and idler pulleys and a fresh belt.
Take a look at the coolant too...might need a good flushing.
-Mac
Others would argue for a Mopar one but the $125 plus cost is too rich for my blood.
Might want to do your tensioner and idler pulleys and a fresh belt.
Take a look at the coolant too...might need a good flushing.
-Mac
I'm gonna replace the gasket first. I just ordered a MOPAR one. The gasket on there now is a Fel-Pro. I installed both the tensioner, and idler pulleys and a new belt this past August when I did the water pump, thermostat and thermostat housing. Coolant is all new since the radiator to. I didn't flush the system but its nice and clear and clean green.
I found my Mopar pump for $86. I'm poor, not cheap.
So last night, on a hunch from a fellow Jeeper I decided to swap out my radiator cap for an old spare I had in my parts bin. Guess what...THE LEAK STOPPED!
I've driven the Jeep over 25 miles since then on highways, and through stop and go traffic, and to my surprise it hasn't leaked a single drop of coolant!
Could the excessive pressure I had in the system, which blew up my radiator have been due to a blocked cap? If so, is it possible that after I replaced my 20 year old radiator the pressure then moved on to my non-MOPAR water pump and gasket which were the next weakest link? It's crazy but I haven't even changed the gasket yet, and its holding with the new cap.
I'm still gonna ditch this cheapo water pump and gasket for the MOPAR stuff when it gets here, but I have to say, this was pretty unexpected.
Here's the cap I installed about a year ago.
And here's the spare cap I put on last night.
I've driven the Jeep over 25 miles since then on highways, and through stop and go traffic, and to my surprise it hasn't leaked a single drop of coolant!
Could the excessive pressure I had in the system, which blew up my radiator have been due to a blocked cap? If so, is it possible that after I replaced my 20 year old radiator the pressure then moved on to my non-MOPAR water pump and gasket which were the next weakest link? It's crazy but I haven't even changed the gasket yet, and its holding with the new cap.
I'm still gonna ditch this cheapo water pump and gasket for the MOPAR stuff when it gets here, but I have to say, this was pretty unexpected.
Here's the cap I installed about a year ago.
And here's the spare cap I put on last night.
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