So, two coolant leaks instead of one...

[Smitty77]

2003 ISL370 CAPS Engine, in a Country Coach.

I posted a few days back, that I had a coolant leak where I found a right angle coupling coupling out of the block. It's located about 1/4 - 1/3 from the front of the engine, on the passenger side, about 2-4" below the head. It has 7/16th tube with a compression nut on it, that had works it way enough loose to drip coolant while parked, and I assume more so while under pressure. Was able to snug it up about 1/3-1/2 turn, dried it off, added two gallons to the radiator tank reservoir of 50/50 Final Charge, and the checked it again after running the engine for about 5 mins where it remained dry. VICTORY! No more leak...

Well, that dang puddle under the engine, two days later, was not dry. And worse, it had fresh looking moisture too it. So, what I felt was victory, turns out to be another opportunity to troubleshoot!

Crawled under again today, and sure enough I still find coolant running the side of the engine. It's just a bit more towards the front of the engine, and I looked up as far as I could see thru the harnesses and hoses running around, but could not see the source.

I'd like to avoid tearing apart the bedroom to take a look from above, but will do so if their is a likely candidate to check up on toe top front 1/4 to 1/3 of the engine. Can anyone think of any likely coolant leak sources up towards the top front of the engine? I did see what looks to be a plate of metal with two bolts attached to it on the side of the block. (Must have been for some equipment that our engined does not have, assume it's a dummy cover plate.) It's moist, and I will go check the two bolts to see if they're loose. But, I see moisture above this place too, but then the trail up the block seems to finish. One wire harness conduit up above it has 'a drop' of coolant, which leads me up towards the top side of the engine...

It's the 3rd of July, and the local Rocky Mountain Cummins or Reno is closed for today, or I'd call them to see if they could get me in for a under pressure test with die. We have plans to leave Sunday 7/5 and head East across Nevada on Hwy 50, but don't want to do that with a known coolant leak.

If I can be pointed at other things to check, even with tearing down the bedroom (about 90 minutes work to get things prepped to open the upper access hatch to the engine), if this braintrust can point me at likely candidates to check up topside.

TIA for any help, and feel free to ask me to try and clarify my rambling descriptions above!

Best to all, and happy 3r do of July!
Smitty

[Smitty77]

Attempting to insert a picture of the tubing/right angle coupling/compression nut that had been leaking.

I did double check that it was/is the light brownish/red coolant that is the Final Charge 50/50 look. Smell tested it to be sure it was not diesel fuel, and took a real good look at and around the lift pump area which is to the front and a bit higher then this coupling. Bone dry.

I've sprayed everything off with fresh water, dried best I could with a rag, and now have a fan running on that area of the engine to keep drying the areas I can't get to with my hands. Will wait an hour or so, then go check to see if I can find any fresh leaks.

A gent that has been helping me off and on here in the RV park, commented that all of those conduits that run around with the wires inside of them, could have accumulated a good amount of coolant leak as I was driving (and things were blowing around some), and that possibly I could still be seeing residual dripping from the first event. I did look at the radiator reservoir tank, and best I can tell it has not dropped any from when I filled it. And I've marked it now so I know where it is level wise at this time.

Hope the picture comes thru, still wondering what this tube is, and where it goes!

Also, still looking for feed back on suggestions on what to possibly look at up a bit higher on the front upper half of the engine. I know that I think it's the return comes out up towards the topside front of the engine, and I can't see that. But, I think that is on the drivers side(?), not the passenger side.

Best to all,
Smitty

[Speedjester]

I'm guessing you could still pressurize the system.. And see where it's coming from.. You can rent a pressure tester at any autozone, advance , napa, pep boys for free... Pressurizing it might make finding the leak easier...

[Smitty77]

Originally Posted by Speedjester

I'm guessing you could still pressurize the system.. And see where it's coming from.. You can rent a pressure tester at any autozone, advance , napa, pep boys for free... Pressurizing it might make finding the leak easier...

After drying rinsing the engine area with leakage with a water bottle, drying with some rags, and running a fan on it of 30 mins. I then started the engine, set the idle to 1000, and ran it for about 35 mins (Wanted to go to 45 mins, but the neighbors in the RV Park pulled back in from an outing, and I just did not feel right pumping diesel exhaust towards their front door any longer!) Silver leaf indicated water temp of 155, and I power off the engine, I went to the radiator reservoir tank and carefully removed the radiator cap - it hissed goo, so pressure had built up.

Climbed back under the coach, and the only remain moisture was along the seams of the oil pan. Touching the oil pan it was mildly warm, so the temps at idle for 35 mins, was not enough to get the engine to full temperature.

I'm going to walk away for a few hours, then take another look underneath to see if any more seepage reveals itself.

Very possible, and hopeful, that I was seeing residual dripping from where the leak from the compression nut had been going enough to lose 2 gallons of coolant. Many little areas for coolant to have been caught up in... Oh, and full block from the pan up, everywhere I could see with my flashlight, had no returning of any sings of moisture - just the bet caught in the seams of the oil pan, mostly coming from an area I could not dry with the rag, between the trans and the front of the engine, covered by the skid pan.

I do feel a bit better that I did not find an obvious ongoing leakage from the 35 min run.

Will feel completely better in three or four hours, if nothing else pops up!

Best to all,
Smitty

[jacwjames]

I assume your coach has a surge tank with coolant level sensor??? If so this will give you a warning if you loose enough coolant to sound the alarm. You also have the Silverleaf system which gives good vitals on the engine.

Do you have any idea how long it took to loose 2 gallons of coolant, when was the last time you checked level when you found the leak.

Right off hand I don't know of anything up high to cause a leak other then any freeze plugs that may be in place. They is a tendency for them to corrode and leak but I would think that after you running the engine for the 35 minutes it would have leaked if it was going to.

On memorial day we had been on the road about 100 miles and decided to pull off for breakfast. Pulled into a Cracker Barrel, wfe went into the restaurant & I proceeded to do my normal walk around. Went to the back of the coach and there was a "river" of coolant flowing away from the coach. Turns out that something got kicked up into the radiator and punched a hole (s) in it. It would leak a gallon of antifreeze about as fast as I could pour it in. Finally got the coach back, ~+$7K repair bill but luckily my insurance covered most of it.

Engine was running fine and the temp was 180 when I shut if off.

Point is you have to loose a lot of antifreeze almost instantly to cause damage OR run your coach a long time without antifreeze. If you go on your trip I would just stop every hour and check it.

[Speedjester]

If you use the pressure gauge. You can actually watch the gauge and see if you actually have a leak..... Running it to build pressure will hide small leaks as they will evaporate once it hits the hot engine....

[Smitty77]

Level was checked before we left home, and I've about 850 miles on it to get where we were when I found the leak. Not a high volume, while not running, it was a very minor dripping situation, until I got the compression nut back tight.

I'll do the check in the AM, and if I see evidence of new leakage, stay over a few days here in Reno and get into the Rocky Mountain Cummins shop to do some more testing. And yes to the pressure gauge test and watching the gauge. I thought I had fixed it this leak, and may have - but should have gone into NAPA and got what I needed to perform a more thorough test. Oh well, we'll see what the AM brings!

Best to all, and thanks for the input so far!
Smitty

[Smitty77]

In the flashlight of the next day, still have a slow steady leak. On the picture, the lower arrow shows some sort of sensor, looks like a heat temperature sensor, as it is strapped to the block. You can see the trail of coolant as gravity works it towards the ground. The upper arrow, is a bit higher then where their seems to be a slight maybe 2-4" ledge, where the block steps in/recesses a bit. Looking at the Cummins manual, it is just above where the flywheel tops out. (It's actually a bit lower then where the upper arrow, behind where the hydraulic hose attached to the PTO runs.) I can't get into see this area, but that is where the coolant is dripping/running down from.

Of course, this is where I can see it coming from, fluid and leaks have away of traveling that could have the origination source elsewhere, that I can't see...

Jim J. mentioned freeze plugs (The last one I remember replacing, was in a 1965 Power Pack 225 Slant Six! Spent I think 75 cents more, and got brass plugs), does anyone know where/if the ISL has freeze plugs? I can't see any, but again, I can't see up and over that little ledge where the block steps in.

The coolant inlet/outlet seem to be towards the front of the rear of the engine, and no signs of loose hose clamps. Any other known hoses, possibly from towards the rear? For example, I could not spot where the OTR heating hoses come from off of the engine coolant?

Appreciate any more tips. I think we'll cancel our plans on heading East across Nevada's Hwy 50. Try to get into the Reno Rocky Mountain Cummins on Monday, if they're not swamped!!

Best to all, and happy 4th of July to all. We feel lucky that we've found this what now seems to be two leaks, here in the RV Park, as apposed to getting a low coolant warning and pulling off the side of the road somewhere!

Smitty

[Smitty77]

Forgot the picture!

[deandec]

If they will allow, view the diagnosis area with the tech before approving the repair so you know what is being done.

I left my rig with them in Reno and had to return to work before the diagnosis was presented. Not sure that I got the least expensive quality fix for my problem. They got about $4k.....

[Smitty77]

Let's try the again!

Sorry, not able to post the latest picture.... In the first one, it's just to the left of the circled area.

Smitty

[Smitty77]

With the light of a new day, and a real telescoping mirror instead of a piece of semi shinny (closer to a flat finish vs glossy) piece of metal held with needle nose pliers - I found the second leak. Surprise, another 7/16" tube going into the block with a compression nut that needed some 'adjusting to the right'. Could not see it without the mirror, and two trips to NAPA for opportunities to add to my tool kit - and I think I got enough of a bite on it to snug it up. Not sure if it is snugged up enough, but for now - no more seepage. I also feel good knowing where the leak is from, and that it would not become a large burst of a hose giving way, even if it were to start leaking/seeping again.

I'll monitor it each night as we work our way towards Denver. And if needed, suspect a real mechanic's tool kit and being able to stand in a pit for access, would make minimum charge shop rate to tighten both of the compression nuts back up...

I still could not see where these two pipes feed, so have no idea why coolant would be going coming in/out of the block.

Best to all,
Smitty

[deandec]

Congrats........hope that is the end of the trouble.

Enjoy the ride.

[deandec]

Congrats........hope that is the end of the trouble.

Enjoy the ride.