Radiator leak on Seneca 35 GS

luckydad71 · 02-18-2021, 09:27 AM

Got home from work last night and the wife told me there was some fluid coming from the engine area of the motorhome. I keep it stored on the side of my house. My last trip was 2 weeks ago when I went to King of the Hammers in Johnson Valley. This was only about a 200 mile round trip and I was not towing anything.

I went outside to inspect and sure enough there is a small amount of radiator fluid on the ground under the driver's side. I inspect and the fluid appears to be coming from the area of the driver's side bottom corner of the radiator. I pulled all of the rubber shroud from around the radiator see if I could determine where the leak was coming from and still could not determine the source.

I know there were problems with this radiator. I bought the motorhome used from a RV Dealer and purchased a bumper to bumper 3/36 mile warranty (I know probably waist of money but I wanted a little piece of mind buying used) that I am thinking about using.

The previous owner left his receipts in the coach and it shows he replaced the radiator in 4/18 and I bought it in 11/18. This was done at a local GM dealer.

Were these radiator's (GM) that flawed that they would only last a few years? If I replace, i'm going to be hesitant going with another OEM part?

Anyone have a similar issue with the older Senecas?

Grumpy · 02-18-2021, 09:37 AM

Quote:

Originally Posted by luckydad71

Were these radiator's (GM) that flawed that they would only last a few years? If I replace, i'm going to be hesitant going with another OEM part?

Anyone have a similar issue with the older Senecas?

Had it with our 08 and it did not affect every rig.

The bottom corner was not crimped properly so over time with the expansion/ contraction you get the leak between the plastic tank and the aluminum core. I would go to a radiator shop and see if they do re-crimping and then pressure test.

luckydad71 · 02-18-2021, 09:50 AM

Thank you! I will be looking for a local reputable shop.

Happy wife / happy life · 02-18-2021, 10:38 AM

Quote:

Originally Posted by luckydad71

Got home from work last night and the wife told me there was some fluid coming from the engine area of the motorhome. I keep it stored on the side of my house. My last trip was 2 weeks ago when I went to King of the Hammers in Johnson Valley. This was only about a 200 mile round trip and I was not towing anything.

I went outside to inspect and sure enough there is a small amount of radiator fluid on the ground under the driver's side. I inspect and the fluid appears to be coming from the area of the driver's side bottom corner of the radiator. I pulled all of the rubber shroud from around the radiator see if I could determine where the leak was coming from and still could not determine the source.

I know there were problems with this radiator. I bought the motorhome used from a RV Dealer and purchased a bumper to bumper 3/36 mile warranty (I know probably waist of money but I wanted a little piece of mind buying used) that I am thinking about using.

The previous owner left his receipts in the coach and it shows he replaced the radiator in 4/18 and I bought it in 11/18. This was done at a local GM dealer.

Were these radiator's (GM) that flawed that they would only last a few years? If I replace, i'm going to be hesitant going with another OEM part?

Anyone have a similar issue with the older Senecas?

Just a thought. I believe the upper radiator hose is on the drivers side. I would make sure the hose clamp is tight. AutoZone and O'Reilly auto parts stores have a tool lend program, borrow a radiator pressure tester and see if you are holding pressure if it's not you may see where the leak is coming from. Hopefully it's a loose clamp ( had it happen to my truck ).

Jagiven · 02-18-2021, 11:19 AM

If your handy, or just want to know, you can add some UV fluorescents to the radiator fluid, and after a good run to mix it in, use a black light (UV). You will see exactly were the fluid has traveled. FYI, you will see it all over your hands and things you touched afterwards too, so I always use disposable gloves when handling the container.

https://www.napaonline.com/en/p/BK_7652663?

https://www.amazon.com/LETION-Flashl...%2C198&sr=8-11
partTypeName=Multi+Purpose+Leak+Detector+Dye&impre ssionRank=7&keywordInput=fluorescent

FYI, some radiator fluids do fluorescence without the die. I suspect none of the new stuff does.

THE MEEKER · 02-18-2021, 11:29 AM

I would recommend to go to an honest mechanic and ask him (or her

) to pressure test the cooling system. He will know right away if its a hose, loose clamp, water pump or if the radiator needs to be replaced. This is the easiest way to determine where the leak is coming from. Good luck!

luckydad71 · 02-18-2021, 12:37 PM

Thanks for the replies. I have a buddy who owns a auto shop and he is lending me a pressure tester. I will be testing this weekend and go from there.

Grumpy · 02-18-2021, 01:32 PM

Quote:

Originally Posted by luckydad71

Thanks for the replies. I have a buddy who owns a auto shop and he is lending me a pressure tester. I will be testing this weekend and go from there.

From experience, it may not leak.

Took mine to the shop they tested no leak. Everything was cold and had contracted back. They had it 3 days and drove it daily then the leak finally reappeared. Those radiators have a mind of their own.

Just an FYI..

luckydad71 · 02-18-2021, 02:44 PM

Good to know....i'll report back with my findings!

Superseneca · 02-28-2021, 11:23 AM

I had a similar experience with my 07 Seneca. The rad would only leak when the unit was park on a slope . It leaked intermittently for 3 years.. never leaked when driving. I finally just replaced it. Took an afternoon to swap it out. All good now.

luckydad71 · 03-02-2021, 11:03 AM

Mine is parked flat on the side of my house and i've probably lost about 3-4 ounces since i've noticed the leak.

I've made an appointment with Colton RV and Truck. Was recommended highly out here and they have told me they will accept my extended warranty.

SurfnTurf · 03-06-2021, 03:09 PM

I just had my second radiator replaced on my 2008 Seneca 36MS and the job cost me about $2300.00. The first replacement was 5 years ago at about 19,500 miles and although 5 years has elapsed, I had only about 4,500 miles on it. The service center had a hard time locating the leak initially but they tracked it down to the plastic portion of the radiator near the base. Seems to me these radiators are crap! I’ve owned dozens or cars and several 3/4 and 1 ton diesel trucks logging well over 200k miles and I have never had a radiator failure in any other vehicle. Hopefully, the new replacement will be my last.

dneeld52 · 03-07-2021, 09:41 PM

I've had our coach less than a month and I was taking it to Elkhart, IN to have Truma upgrade the tankless water heater when I had a major engine alarm and had to quickly pull off the road and beg a bucket of water from a 7/11. while waiting I noticed a stream of water coming from underneath the cab. My DEF hoses were leaking terribly. Fortunately, the Freightliner dealer was still open and I drove the 20 miles to drop it off.
Turns out there is a crack in the weld at the bottom of the radiator hose nipple.
I have only 9,000 miles on the unit.
He was not sure the radiator was still under warranty, but he was definitely aware that the DEF issue is covered.
It does make you wonder who supplies the radiators to Freightliner.

SloPoke · 03-08-2021, 11:22 AM

I believe that the Radiator is built like our Suburban's Radiator... and Aluminum core that is sealed to plastic tank ends. I went thru radiator after radiator for years and years... they would leak after the vehicle cooled down and every dealer / radiator shop said it was not "shop serviceable" since they could not get them to re-seal at the tank joints once taken apart.

After the warranty expired, I eventually went to an aftermarket radiator with metal tanks that were soldered to the core and it lasted for years afterwards.

Grumpy · 03-08-2021, 11:48 AM

Quote:

Originally Posted by SloPoke

every dealer / radiator shop said it was not "shop serviceable" since they could not get them to re-seal at the tank joints once taken apart.

All the shop needed to do was tighten the crimp. There was no need to take them apart it was just a matter of a bad crimp on the driver's side. Every one of the KODIAK's that failed was in the same spot.

Happy wife / happy life · 03-08-2021, 02:30 PM

A few of the shop owners i had dealt with ( I sold them GM parts ) used the Champion brand aluminum radiators. They make direct fit replacement radiators with a life time warranty. They are all welded aluminum. I know they make them for car and pick-ups but I'm not sure about motor home chassis. As far as direct fit, on my 84 gmc i went from 2 core to 4 core so I had to change my upper mount cushions on DW's 91 Chevy c1500 p/u it was direct fit. Are they cheap/inexpensive NOPE!! This is one of the cases " you get what you paid for". I have been very happy with their product. I went through Jeg's performance parts,they had the best price their service is outstanding and the buy the ride. If your under warranty you are probably stuck with O.E.,but if not it might be worth talking to your Tech. ( mechanic ) about it.

Grumpy · 03-08-2021, 02:45 PM

Quote:

Originally Posted by Happy wife / happy life

I know they make them for car and pick-ups but I'm not sure about motor home chassis.

It was for the KODIAK/TOP-KICK 5500 medium duty truck chassis, nothing MH specific.

Happy wife / happy life · 03-08-2021, 03:56 PM

Quote:

Originally Posted by Grumpy

It was for the KODIAK/TOP-KICK 5500 medium duty truck chassis, nothing MH specific.

From the early 80's to mid 80's Chevy dealers were able to get Kodiak parts but later on you had to be a Kodiak/Top-kick dealer. I believe early model used Harrison radiators with brass tanks,are those the ones you could pinch repair or did they go to the plastic tanks that the pinch would work. Just a side note the 366 and 427 tall block engines were great work horses.

luckydad71 · 03-10-2021, 10:15 AM

Well I dropped it off yesterday at Colton RV and Truck and have not heard back from them. The shop came highly recommended and the service tech who checked me in was super thorough. They were going to track the problem down, create and estimate, and then contact my extended warranty (Campers Edge) to see what they say. I'll keep you posted.

Thanks for all the advice and real world experience. I'm hoping warranty covers this one and if it happens again, I will definitely look into an aftermarket radiator.

luckydad71 · 03-11-2021, 03:58 PM

Well, got a call this afternoon and they could not track it down

The guy was super nice. Said they parked it for a couple of days thinking it was a cold leak and nothing appeared. They then took it out and brought it up to temperature and still nothing. He said he has rerouted the overflow because it was routed to the area where the fluid was appearing. This was in hopes that if it is the overflow I will be able to tell.

Like others in the thread have said, these radiators have a mind of their own. I'm heading out camping in a couple of weeks and will be taking a gallon of coolant with me just in case. Going to be a little nerve wrecking driving not knowing if it going to happen again.

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