Cummins antifreeze leak

[Usa1chris]

Has anyone expierenced this problem... I have a 07 Dutchstar with a cumming diesel 400 engine... about 24,000 miles On the last 8-9 trips I have noticed antifreeze that has blown out at the rear hatch area belown ...Not a lot but enough that finally I need to add several gallons of the 16.00 a gallon peak special antifeeze... Is there a overflow in the rear ? I don't think it coming out around any hose or the cap?? ... I talked to a service center and they said it could be the air system over pressuring the coolent system??

None of this makes any reason to me Any thoughts

Thanks, USA1Chris

[bdpreece]

Don't know about Dutchstar but I just had my Endeavor in for service at a Freightliner shop and asked them to check the coolant SCA. They called to tell me my coolant was quite low and that the plastic coolant reservoir tank was cracked in two places allowing coolant to leak out. I had them replace the plastic tank with an all metal one for a Freightliner truck. I have read that many motorhome manufacturers used the plastic tanks and that they do not last.

[Harm]

Chris: on my '06 there are a couple of plastic t-fittings directly over the rear differential that cracked and leaked anti-freeze blowing back as you drive. Just something else to check.

[Sky_Boss]

Originally Posted by Harm

Chris: on my '06 there are a couple of plastic t-fittings directly over the rear differential that cracked and leaked anti-freeze blowing back as you drive. Just something else to check.

We had something similar. I think Wayne might be referring to a "Y" kind of fitting that allows hot coolant to be diverted to the Motor Aid water heater. On my Spartan Chassis they were on the passenger side over the area of my rear jacks which made me think it was hydraulic fluid. WHEW. The hoses connecting to the Y fitting were leaking and we replaced the fittings, cut about 1/2" off the hoses, used new clamps and fixed that. there are 2 fitting, on to and one from the hot water heater.

However...my leak was found a week after I bought it while sitting in my storage building not going anyway in the middle of January. I did not experience any kind of "blow buy" to tell you my symptoms were the same as Chris's.

BTW...finding those Y fittings was a real PIA. It took Newmar a few days to find them. Recently I had my hot water heater replaced and when I got the extra parts back...it came with 2 of those Y fittings. So...if you find that to be the problem, you might find it easier to get ahold of Suburban to get a set. The ones from Suburban are NOT plastic but some kind of metal that looks like brass.

[Usa1chris]

I thought I would let everyone know that I have solved the antifreeze leak on my 2007 Dutchstar...I pulled the MH out of storage and refilled the reservoir to the required cold level. I started the engine and let it run for approx. 30 mins. to reach property temp and pressure. First, I saw the red coolant leaking around a setscrew on the metal reservoir...so with a alan wrench I tighten the very lose setscrew up! Second, as it continued to run I saw red coolant on the bottom of the metal reservoir very small amount and a tiny few drops every few mins. I wipe the area off and at first thought there could be a pin size hole in the resorvoir bottom . I checked all the hoses, clamps and fitting on the reservoir and could not find any leaking.. Finally, ..I took a mirror and put it in behind the resorvoir and discovered there are 3 lines that come into to top rear of the reservoir and discovered the center fitting was leaking the antifreeze showing up on the bottom of the unit. I am unsure if these lines are pressurized with air or not?? So I decided to let the professional fix this leaking fitting... I think it will require diconnecting the whole reservoir box and other fittings to tighten the fitting...Thanks for all the advice..

One finally note..I love my Motor Home and I purchased it new but I will tell this about 60% of my repairs, leaks and parts failing falling off... have been items left loose or incorrectly installed by factory, dealer or secondary vender ...I've had my inmotion satellite not working (new) because the people that made the unit did not tighten one little nut. My steering collumn came loose to the point I could move it right to left up and down 3-4 inches... loose bolts left untighten on lower collumn shaft. The key to start unit turned completely around and the key was stuck...never correctly tightened in dash.... the air horns stopped working..and more than 15-20 items that I have been able to fix, replace or repair...So when they say after few thousand mile to check tighten and let your dealer service dept. go over your new unit....I think it would be a good idea.. Also, All motor Homes are built with 100's of vender parts and components...I have found even out of warrenty that a call to these vender or components builders can really make a differents. I have got replacement parts on parts on some items for free or little cost( especially if they have had similar problems with the part) and also, some great solutions for repairs..

take care,
usa1 Chris

["007"]

Thanks for the follow up Chris, why is it always in the back of something to make a easy job harder to do. Things do loosen up from road vibrations on some of our good roads ?? around the U.S.A.
I had a anti leak behind a stud for mounting the engine manifold, found it when anti short out at you after removing the only easy stud to remove, all others had to be drilled out.

[dennis45]

Originally Posted by Usa1chris

Has anyone expierenced this problem... I have a 07 Dutchstar with a cumming diesel 400 engine... about 24,000 miles On the last 8-9 trips I have noticed antifreeze that has blown out at the rear hatch area belown ...Not a lot but enough that finally I need to add several gallons of the 16.00 a gallon peak special antifeeze... Is there a overflow in the rear ? I don't think it coming out around any hose or the cap?? ... I talked to a service center and they said it could be the air system over pressuring the coolent system??

None of this makes any reason to me Any thoughts

Thanks, USA1Chris

Take your pressure cap off and get it tested. Most repair shops can do this. I had coolant loss for a while and could not see any sign of a leak. Tested the cap and found it releasing 5-6 psi lower than the 15 psi rating. After testing three new caps, I finally got one that held 15 psi. Installed the new cap and have not added a drop since.

[cptngym]

Originally Posted by dennis45

Take your pressure cap off and get it tested. Most repair shops can do this. I had coolant loss for a while and could not see any sign of a leak. Tested the cap and found it releasing 5-6 psi lower than the 15 psi rating. After testing three new caps, I finally got one that held 15 psi. Installed the new cap and have not added a drop since.

I need to check my cap. Loosing a little antifreeze and do not find it on the ground. 7 hour run lost about 1 1/2 inches in the plastic tank.