Heat exchanger / repair or replace

Discussion in 'General Maintenance/Repair Questions' started by Jaay757, Oct 27, 2014.

  1. Jaay757

    Jaay757 Member

    137
    Jun 18, 2012
    Buzzards Bay, Mass
    2006 sea ray 340 sundancer
    8.1's, ZF IV V drives
    While winterizing I noticed my coolant reservoir tank was low. I refilled it and overnight I lost the coolant I added. I checked the end cap of the heat exchanger on the raw water side and located my missing coolant. So there is obviously a crack or break inside the exchanger on the coolant side to allow this. From what I can see inspecting from the end caps there does not appear to be any corrosion, however I can't inspect the whole unit. So my question is should I replace with new or take it to a radiator shop and try to have it fixed if it can be even done. I hate to put good money to bad, but spending $900 is killing me. Also has anyone used any of the aftermarket exchangers? I know there are a few out there. Any suggestions would be appreciated.
    Thanks
    Jason
     
  2. Jmwarren

    Jmwarren Member

    417
    Jul 14, 2011
    Ontario
    390 Motor Yacht
    Cummins - 480CEs
    While I've never had to replace one, I've been told that the exchangers on 8.1s are essentially throw away.

    You can likely get a little longer out of it by having it repaired (they may just braze the tubes shut) but eventually the others will start to go.
     
  3. Air O'Nautical

    Air O'Nautical Active Member

    Feb 5, 2008
    Stamford CT "Ponus Yacht Club"
    1995 400EC. Raymarine E80,4kw dome, Garmin 235 gps,
    2013 7.4L Mercruiser Blue water.
    Hurth straight shaft 630's,
    Westerbeke 7.0 BCG
    Replace it with a aftermarket cooler.
    I like the SeaKamp brand sold from Go2marine at decent prices.

    Good luck,
     
  4. mmcguire2002

    mmcguire2002 Member PLATINUM Sponsor

    547
    Mar 3, 2008
    MDR, CA
    2003.5 Sea Ray 340 DA
    8.1 Horizons
    Going through this right now. Took them to a radiator shop and they said to replace them. Parts just came in and my mechanic is installing this weekend.
     
  5. Jaay757

    Jaay757 Member

    137
    Jun 18, 2012
    Buzzards Bay, Mass
    2006 sea ray 340 sundancer
    8.1's, ZF IV V drives
    Thanks guys looks like I'll be looking for a replacement.
    Michael what did you use as a replacement OEM or aftermarket? I have looked at the seakamp and mrcool also offers one for a couple hundred dollars less.
     
    Last edited: Oct 28, 2014
  6. mmcguire2002

    mmcguire2002 Member PLATINUM Sponsor

    547
    Mar 3, 2008
    MDR, CA
    2003.5 Sea Ray 340 DA
    8.1 Horizons
    I believe we went OEM, but will verify this weekend for you.
     
  7. Tomco

    Tomco Member

    160
    Aug 16, 2012
    Ottawa
    2003.5 Sundancer 340; Raymarine RL70
    496 MerCruiser w/Bravo III Drives
    I have had to replace both of mine - one two seasons ago and one at the beginning of this season. When I researched it the general consensus seemed to be that having them repaired may buy you a little more time but you were going to have to replace them in the end. I decided to go with just replacing them up front. The first one was OEM which I purchased from Performance Product Technologies (https://www.perfprotech.com/mercury-outboard-parts-mercury-outboard-motor-parts-diagrams) and the second was aftermarket from eBay. I've not had a problem with either ... but the real test will be how long they last! This was a very easy repair that I did myself ... I took a bunch of pics, I should put them in its own thread. I still have the old one sitting in the garage - was wondering how much all the copper would be worth if I take it to a recycler.
     
  8. rondds

    rondds Well-Known Member SILVER Sponsor

    Oct 3, 2006
    Jersey Shore
    2001 380DA
    Merc 8.1s (2008)...Hurth ZF 63 V-drives...WB 7.0 BCGD (2013), Garmin 8208 & 740 MFDs, GMR 24xHD dome
    I've purchased engine oil coolers with MrCool products (in my previous boat). Top notch stuff. I just had to spray them Merc. Black. Your job is pretty easy - just plan on dumping a fair amount of coolant. Keep a shop vac handy to catch it. If the vac is clean you can put it back in.

    [​IMG]

    [​IMG]
     
  9. Jaay757

    Jaay757 Member

    137
    Jun 18, 2012
    Buzzards Bay, Mass
    2006 sea ray 340 sundancer
    8.1's, ZF IV V drives
    Great info, thanks guys, I already have the exchanger removed as I thought I would try to have it repaired while the boat was laid up, but that has since changed as I believe now I will just replace it.....
    Thanks again
    Jason
     
  10. Jimmy Buoy

    Jimmy Buoy Active Member

    Dec 3, 2008
    Sarnia, Ontario, Canada
    340 Amberjack
    twin 8.1S 370 Hp + 4.5 Westerbeke Genset
    You'll want to replace the two rubber "seats" that the cooler sits on at the same time. The old ones get hard and start to leak during the winter when things tend to shrink...
     
  11. Air O'Nautical

    Air O'Nautical Active Member

    Feb 5, 2008
    Stamford CT "Ponus Yacht Club"
    1995 400EC. Raymarine E80,4kw dome, Garmin 235 gps,
    2013 7.4L Mercruiser Blue water.
    Hurth straight shaft 630's,
    Westerbeke 7.0 BCG
    I'm trying to figure out what part you mean ??

    Edit.......you must mean the end cap gaskets.
    His new cooler should come assembled with new caps and gaskets installed.
    At least my SeaKamp ones did.
     
    Last edited: Oct 31, 2014
  12. Jaay757

    Jaay757 Member

    137
    Jun 18, 2012
    Buzzards Bay, Mass
    2006 sea ray 340 sundancer
    8.1's, ZF IV V drives
    The cooler sits into 2 seals onto the top of a manifold on the 8.1's. #14
     

    Attached Files:

    Last edited: Oct 31, 2014
  13. Air O'Nautical

    Air O'Nautical Active Member

    Feb 5, 2008
    Stamford CT "Ponus Yacht Club"
    1995 400EC. Raymarine E80,4kw dome, Garmin 235 gps,
    2013 7.4L Mercruiser Blue water.
    Hurth straight shaft 630's,
    Westerbeke 7.0 BCG
    I see....part # 26-865066 - SEAL - Heat Exchanger to Crossover. $11.31 each - 2 used.I'll have to look at that next time I'm working on an 8.1.

    Thanks,
     
  14. Jimmy Buoy

    Jimmy Buoy Active Member

    Dec 3, 2008
    Sarnia, Ontario, Canada
    340 Amberjack
    twin 8.1S 370 Hp + 4.5 Westerbeke Genset
    Those are the ones!!
     
  15. Jaay757

    Jaay757 Member

    137
    Jun 18, 2012
    Buzzards Bay, Mass
    2006 sea ray 340 sundancer
    8.1's, ZF IV V drives
    Question: so the coolant is in the heat exchanger, raw water side, is there a chance the raw water mixed with the FWC. I tested the antifreeze remaining in the manifold below the exchanger -20. I believe the pressure on the FWC side is higher than that on the RWC side which would not allow this but just wanted to get your thoughts. Those that changed out the exchangers did you also flush and refill the FWC.

    Thanks
    Jason
     
  16. Jaay757

    Jaay757 Member

    137
    Jun 18, 2012
    Buzzards Bay, Mass
    2006 sea ray 340 sundancer
    8.1's, ZF IV V drives
    Anyone???
     
  17. Jimmy Buoy

    Jimmy Buoy Active Member

    Dec 3, 2008
    Sarnia, Ontario, Canada
    340 Amberjack
    twin 8.1S 370 Hp + 4.5 Westerbeke Genset
    When one of mine leaked, the coolant was forced out of the system into the raw water side of the exchanger and went out the exhaust ports. It eventually drained the reservoir. I don't think raw water entered the coolant side...
     
  18. rondds

    rondds Well-Known Member SILVER Sponsor

    Oct 3, 2006
    Jersey Shore
    2001 380DA
    Merc 8.1s (2008)...Hurth ZF 63 V-drives...WB 7.0 BCGD (2013), Garmin 8208 & 740 MFDs, GMR 24xHD dome
    When I read this I didn't understand the question. Still kinda don't. The coolant is in the heat exchanger- YES. Coolant does not run through the raw water side.

    Can coolant leak into the raw water, and vice versa - YES. If the heat tubules are leaking.
     
  19. Jaay757

    Jaay757 Member

    137
    Jun 18, 2012
    Buzzards Bay, Mass
    2006 sea ray 340 sundancer
    8.1's, ZF IV V drives
    Thanks Jim, Thats what I thought, that is what mine was doing also, however as it is laid up now for the winter I began to question myself if coolant could enter the raw water why not vice/versa. I did test what was left in the system and appeared to be coolant to -20.
    Thanks
    Jason
     
  20. rondds

    rondds Well-Known Member SILVER Sponsor

    Oct 3, 2006
    Jersey Shore
    2001 380DA
    Merc 8.1s (2008)...Hurth ZF 63 V-drives...WB 7.0 BCGD (2013), Garmin 8208 & 740 MFDs, GMR 24xHD dome
    Reanimating a dead thread...
    8.1s, port engine, coolant gone from the reservoir. it's not in the bilge and crankcase oil is clean. Need to replace the heat exchanger and would also like to take the opportunity to drain, flush and replace coolant in the fresh water side of the system. Manual says capacity is 20 quarts. How do you drain it all out? Is there a plug somewhere at the lowest point?
     

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