Mystery Coolant Leak

[dontech]

Hi All,
I could use some help with a perplexing coolant leak on my 2008 Berkshire. I posted the issue in detail at RVPics.com here. (Moderator remove the link if it is not appropriate.)

I scoured the internet for clues to solving this problem. I could not even find anything helpful about accessing the engine from the bedroom cover. We finally got it uncovered. I doubt you will find any other pictures of the engine viewed from the bedroom of your Berkshire.

After reading the post, if you have any ideas, I would appreciate hearing from you. If you don't post at RVPics, please leave me a message here or email me. Thanks for your interest.

Don

[NO3putt]

Don, can not help with the leak, but thanks for the pictures, now I have some idea how to get the engine cover off. Good luck with leak.

[fonzie]

If it was me I would start engine and let it warm up to operating temperature and see if that big coolant hose from the rad on the right springs a leak.

[NV245]

Have you tried to find a radiator pressure tester? Autozone has a loaner program, however I don't know if one is in their inventory. I hope it isn't so, but I have had a 5.9 Cummins headgasket leak without coolant/oil cross contamination. (the leak was in the thermostat area). There is also ultraviolet coolant leak dye which will glow under UV (black) light. I also hope you are using heavy duty Diesel coolant (I usually have to go to NAPA). Good luck, I'm very curious to hear the results.

[DAISY BOYKIN]

Don,
I had the very similar leak on a automobile, Couldn't find where the antifreeze was leaking from. I did a little search on Google and found the overflow tank had a small split on the bottom of the tank. It was a seam
that would not always leak but began to get worse over time.

Just a suggestion. Also look at freeze plugs??

[romeofrosty]

Check the weep hole below the water pump's pulley. See if you have any water leaking from there. Get yourself a decent inspection mirror & a good flashlight & start scanning around. Given how dusty the engine looks, you should be able to look for a clean trail in the dust for the trail made by the leak, if it is on the engine itself.

[fonzie]

Could this be a leak at top right corner of rad?

[puff]

Most auto parts stores now have a dye you put in the coolant and then let it warm up. It comes with a special pair of glasses and the leak shows up like a beacon. That is the easiest way to find it and fix from there.

[boowho]

At least I now know what my engine MIGHT look like. I have the RB model and the hatch in the bathroom floor is real easy to get to...... Nothing to remove but the hatch door itself.

BUT.... I've taken out every fastener I could find, tugged like hell on the cover and it will NOT come loose. Phil, you ever had your open??

OBTW, I have nothing to contribute to your original problem... Sorry.

Boowho??

[silver]

Originally Posted by dontech

Hi All,
I could use some help with a perplexing coolant leak on my 2008 Berkshire. I posted the issue in detail at RVPics.com here. (Moderator remove the link if it is not appropriate.)

I scoured the internet for clues to solving this problem. I could not even find anything helpful about accessing the engine from the bedroom cover. We finally got it uncovered. I doubt you will find any other pictures of the engine viewed from the bedroom of your Berkshire.

After reading the post, if you have any ideas, I would appreciate hearing from you. If you don't post at RVPics, please leave me a message here or email me. Thanks for your interest.

Don

Hi Don,

Well you passed the first test and got the hatch opened. It will not be any easier the second time. Don't ask me how I know. I cut the wood down 1/4 inch and now it is much easier. I also replaces the bolts for latches. I can now get the hatch off in minutes.

On to your problem. I have read many threads here and in IRV2 talking about split plastic radiator tanks. As the fluid was coming from the top of the engine this is probably a good bet. The low co-lent sensor is in the plastic tank. Can you fill it and put pressure on the tank? A cheep pressure tester is a old bike tire cut in two, cap one end and stretch other over the tank opening. As soon as you start to pump up the tube if the tank is leaking you should know.

You can also isolate the front of the coach, all the plumbing and the heater going to the dash. Under the coach on each side of the frame at the back are T valves. One on each side. One for feed and one for return to front of coach for heater. They were original yellow. You could shut these to be sure the problem is isolated to the engine and not heater hoses going to the front of the coach.

I hope some of this helps.

[DanielJ]

I'm interested in how your situation progresses. I have a 2008 also and I also had coolant loss over the winter. I called freightliner and the customer service person thought it was likely a vapor phase loss since I never saw a pool of coolant under the rig. I'm planning on moving it into a campground an hour away Friday. We'll see how it goes ...

[Phil57]

Bill I have had mine open for no good reason other than I wanted to know how to do it. It is a pain and the cover is heavy.
I also have nothing to add but will be watching to see what it was.

[SKnight]

It's really good that it's actively leaking actually. Nothing worse than a mystery coolant disappearance.

Sounds like a pressure leak, since you can fill it up, it's fine, you start it, and it flows. Again, sounds fortunate as something like a freeze plug typically will just leak.

Fill it up with water, put the pressure tester on it as mentioned, and then put some pressure to it. The cap should be marked, 15PSI for example. The gauge typically will be marked to match (14-16, 18-20, and so on.)

You probably don't need to go for max pressure, run it up to 5PSI and take a look, no leak, 10PSI. Once coolant hits the ground, go for it. Bright flashlight and the eyes.

Good luck!

[silver]

Here is a picture of the back of the radiator without body on. May help understand how it goes together

[speedmerchant]

I agree with the guys here to do a pressure check. Another rare but possible area that people forget about and don't realize is the air compressor attached to the engine. Passenger side, near the top half of the engine, right about where your hand is in picture 8 but on the side of the block. This air compressor uses the engine coolant for cooling. I can't remember if it is fed by lines or directly from the block, but it could possibly be leaking from a gasket or hose in that area? Just another source that might go overlooked. Keep us posted and good luck.

By the way I had a lower rad hose clamp that rotted away and slowly started puking coolant. Easy fix but the two lower rad hose clamps are susceptible to lots of water spray and road debris. Worth a check as well.

James

[dontech]

Thanks so much for all the responses. Now I can go outside tomorrow armed with plenty of new ideas. I will be sure to post the final results.

-Don

[AREA51]

dontech,

I had a mystery leak on my 2008 Berkshire 360 QS 340 HP Cummins. It turned out to be a freeze plug (cap Plug) under the valve cover. There are 11 of them and the ones in mine were made from a zinc material that reacted to the coolant. I ended up with a couple of gallons anti-freeze in the crankcase. Cummins stood behind it and replaced all of them with stainless steel plugs.

See attached photo.

Good Luck
AREA51

[dontech]

I made some further observations this morning and posted an update with photos here.

Since you guys gave me such great advice yesterday, I thought I would wait for further feedback before I get out the wrenches. Let me know what you think about what I found today.

[SKnight]

That's headed towards the water pump, it's directly above that corner, about halfway up the engine.

Really simple to change it, once you can get to it. Unfortunately, that doesn't look like that's possible with that engine bay.

[gasman94]

I've got mine in the shop right now for a leak without a detectable source. I've got a '14 and have smelled antifreeze when it's hot, since new. Had it pressure checked in Gaffney and they said that they couldn't see anything, but added two quarts. Level is down again with less than a thousand miles. I'll update as I find out more.