some trucks have air operated heater controle vales most times in the bunk and if they go bad it will push air right into the cooling system F/L was bad for this also a cylinder that is not fireing because of loss of combustion will also pass the the test and will push air into the cooling system.
Just worked on mine today tried the bubble test was getting plenty of bubbles ,when I wold release cap it had no pressure on it. Cleaned the seat for radiator cap and tighten ears on cap bubbles gone ,if your cap is not seating it will loose water ,hoping this is my problem. I was not loosing alone of water but some.
A buddy of mine had a john deere tractor (i know its not cat) but he also had that problem, ended up changing gaskets and head 3 times him self and at the end he changed the water pump which fixed it.
Maybe the water pump is sucking air and cavitating. try running it with the water pump belt removed and look in the surge tank for bubbles. this test works best with thermostats removed but you could try without doing that. also you need to leave the combustion gas tester fitted for 10 minutes- which you may have done but not shown in vid for obvious reasons. then put it side by side with new fluid. i have found the color change isnt as dramatic as they show on the packaging but side by side you can see the difference. make sure you have properly ruled out the radiator cap by testing at rated psi or fit a new one
I have big bubbles in overflow tank only when giving a throttle and it bubbles a bit right after releasing the throttle... Now i did as you said, removed thermostat and belt from water pump, fired up, throttled up amd zero bubbles.. So dose it means no combustion gasses are entering in to cooling system? Thanks
Hi, i had a water pushing problem on c15 cat last winter, didnt notice much when i was pulling light loads in canada but then i started pulling 140000lbs loads and it started pushing alot. And last summer i Rebuilt the motor and it slowed down for a bit, or atless i thought. At first i thought maybe i over filled it and later i found a couple of leaks. But all in all i had to add coolenf and now its pretty bad again. Ive notice its happening around 190 and hotter. I did a block tester today i got some air at 170 but it didnt change colors either. How can i block the air compressor? And some told me the water pump or rad could be related ?
To block the air compressor just locate the coolant into the compressor and bypass it by using a hose to remove the compressor from the coolant system. Put a hose from the block back to the block.fill up the coolant and run it again.
Hey,where did you get the red fluid at,,,because in Bradford Pa, nobody can get it,, I got the blue at auto zone, that was all they could get. Advance,napa can't get red either.
Cats Are Famous for Cracked Cylinder Heads and Dropped Liner causing head gasket to allow combustion into the Coolant system you can isolate the air compressor by disconnecting the air discharge line this will not allow the air compressor to build pressure and if you want to take it a step further you can block off the coolant lines on the compressor but you don't want to run the engine very long with coolant blocked with the compressor eliminated if you still have bubbles in you coolant with your tester your getting compression pressure in the system we have tried the tester fluid with no success hope this helps
@@Speedfreak1984 how did you finally determine it was head gasket? Why didn't the chemical tester work? I'm going through the exact same thing right now, tried the tester a few times and nothing 🤷🏼♂️ How did you determine it was the head, and did you complete the job yet, did it fix it? Thank you very much. Truck is in the shop now for this.
@@Speedfreak1984 was it obvious when you pulled the head...and then it fixed the problem? Did you do a full in-frame rebuild at the same time..or just head gasket and slap it back together?
@@Speedfreak1984 dang, same thing here. Won't fail a hydrocarbon test and have everything bypassed the damn thing still blows bubbles. Probably a head gasket or cracked head
TheBaron97 back in may 2019 replaced head gasket. And recently I notice coolant being push out of the overflow. Truck runs fine. Tried isolating the air compressor coolant line from the water pump and no bibles any more. I did replaced the air compressor but problem still exists and believe it was wasted time and money but how could the water pump create air?
@@Speedfreak1984 but your leak test didn’t change colors, when you hooked up the c02 then it changed - first indication showed no head problems right? Don’t understand the difference, Have this problem but haven’t done leak test yet
some trucks have air operated heater controle vales most times in the bunk and if they go bad it will push air right into the cooling system F/L was bad for this also a cylinder that is not fireing because of loss of combustion will also pass the the test and will push air into the cooling system.
Just worked on mine today tried the bubble test was getting plenty of bubbles ,when I wold release cap it had no pressure on it. Cleaned the seat for radiator cap and tighten ears on cap bubbles gone ,if your cap is not seating it will loose water ,hoping this is my problem. I was not loosing alone of water but some.
Bubbles is a major indicator you shouldn't have that much pressure in the system
A buddy of mine had a john deere tractor (i know its not cat) but he also had that problem, ended up changing gaskets and head 3 times him self and at the end he changed the water pump which fixed it.
ended up being a head gasket
@@Speedfreak1984 So the test didn't work?
Wait engine head gasket was bad or air compressor head gasket was bad?? Thank you
Maybe the water pump is sucking air and cavitating. try running it with the water pump belt removed and look in the surge tank for bubbles. this test works best with thermostats removed but you could try without doing that.
also you need to leave the combustion gas tester fitted for 10 minutes- which you may have done but not shown in vid for obvious reasons. then put it side by side with new fluid. i have found the color change isnt as dramatic as they show on the packaging but side by side you can see the difference.
make sure you have properly ruled out the radiator cap by testing at rated psi or fit a new one
Fast Track Mechanic this truck the water pump have gear and can't remove is more difficult to diagnostic
I have big bubbles in overflow tank only when giving a throttle and it bubbles a bit right after releasing the throttle...
Now i did as you said, removed thermostat and belt from water pump, fired up, throttled up amd zero bubbles..
So dose it means no combustion gasses are entering in to cooling system?
Thanks
@truckmechanicbasics4135
And if they r not gasses, then why and from where water pump would get air to make any bubbles?
Hi, i had a water pushing problem on c15 cat last winter, didnt notice much when i was pulling light loads in canada but then i started pulling 140000lbs loads and it started pushing alot. And last summer i Rebuilt the motor and it slowed down for a bit, or atless i thought. At first i thought maybe i over filled it and later i found a couple of leaks. But all in all i had to add coolenf and now its pretty bad again. Ive notice its happening around 190 and hotter. I did a block tester today i got some air at 170 but it didnt change colors either. How can i block the air compressor? And some told me the water pump or rad could be related ?
To block the air compressor just locate the coolant into the compressor and bypass it by using a hose to remove the compressor from the coolant system. Put a hose from the block back to the block.fill up the coolant and run it again.
Hey,where did you get the red fluid at,,,because in Bradford Pa, nobody can get it,, I got the blue at auto zone, that was all they could get. Advance,napa can't get red either.
@@stephenkille5316
www.amazon.com/Lisle-75730-Diesel-Detector-Fluid/dp/B000I16L90/ref=sr_1_1?keywords=%22lisle+75730%22&qid=1572817175&sr=8-1
I have a duramax doing the same thing. Could it be a heater core leak?
Nope head gasket
@@Speedfreak1984 Or EGR cooler.
could be a air compressor that blew a head
I have a 3406 with the same problem, any update?
head gasket
I'm having the same problem does the liquid matter if it's diesel or gas?
nope some times it works but i hsve had it not change colors just look for bubbles
Cats Are Famous for Cracked Cylinder Heads and Dropped Liner causing head gasket to allow combustion into the Coolant system you can isolate the air compressor by disconnecting the air discharge line this will not allow the air compressor to build pressure and if you want to take it a step further you can block off the coolant lines on the compressor but you don't want to run the engine very long with coolant blocked with the compressor eliminated if you still have bubbles in you coolant with your tester your getting compression pressure in the system we have tried the tester fluid with no success hope this helps
Arent you supposed to pump it?
don't need to id if pushing air in
Lol
Any updates?
Nope still in the yard
@@Speedfreak1984 i am having same issues with a isx15 cm871. Just wondering. Thanks
I have a tractor doing the same exact thing I have no idea what it is
head gasket
@@Speedfreak1984 how did you finally determine it was head gasket?
Why didn't the chemical tester work?
I'm going through the exact same thing right now, tried the tester a few times and nothing 🤷🏼♂️
How did you determine it was the head, and did you complete the job yet, did it fix it?
Thank you very much. Truck is in the shop now for this.
@@Speedfreak1984 I just can't understand why the tester doesn't work?
How can science lie
What's the point of the tester then?? 🤷🏼♂️
@@greenstar32 I talked to a lot of shops and decided to pull the head.
@@Speedfreak1984 was it obvious when you pulled the head...and then it fixed the problem? Did you do a full in-frame rebuild at the same time..or just head gasket and slap it back together?
Air compressor. Problems R. Head engine
ended up being a head gasket
@@Speedfreak1984 dang, same thing here. Won't fail a hydrocarbon test and have everything bypassed the damn thing still blows bubbles. Probably a head gasket or cracked head
TheBaron97 back in may 2019 replaced head gasket. And recently I notice coolant being push out of the overflow. Truck runs fine. Tried isolating the air compressor coolant line from the water pump and no bibles any more. I did replaced the air compressor but problem still exists and believe it was wasted time and money but how could the water pump create air?
@@Speedfreak1984 but your leak test didn’t change colors, when you hooked up the c02 then it changed - first indication showed no head problems right?
Don’t understand the difference,
Have this problem but haven’t done leak test yet
Any update on this? I have the same problem. Waterpump?
Haven't fix it yet
Been running mine for 2 years with this condition. Figured I'd just run it till it gives up the ghost.
@@Joe6packAmerican hey kerry have you figured out what was wrong with your truck?
Nope, never did. Still running. LOL
@@Joe6packAmerican what engine you got?