Leaky Coolant Hose M35B

[Breakin Away]

I have a slow leak of antifreeze near the heat exchanger (rear) end of my M35B engine. I'm gradually narrowing down the exact location, and currently I think it's coming from the hose that runs into the port side of the HX. Tightening the hose clamp did not stop it. It may be somewhere else, but I'm starting to fear that there might be a crack near the end of the hose, which I assume will only get worse as the crack propagates. I may try a second hose clamp, but I'm coming to the realization that it may need to be replaced, since it's about the only hose left with original factory paint. The parts manual (#201021) identifies it as part #019059 (#15 in attached picture), 26" long x 7/8" wire inserted hose. Having never worked with wire-embedded hose, I'm concerned about how to make any tight bends that are needed. Is there a tool that I need to get? Do I take it to a shop to do the bends?

If I have to replace that hose, I might as well do the adjacent raw water hose (which is the other one still with factory paint), identified as #200439 (#16 in attached picture). This one has very intricate bends, and appears to be custom made by Westerbeke (since the parts manual does not even specify a length). Can you guys recommend a source for this one?

[Stu Jackson]

Photos here:  http://c34.org/bbs/index.php/topic,4588.msg27079.html#msg27079

Don't know a source other than a Universal dealer or TOAD.

[KWKloeber]

Breakin:

I have a little knowledge on this. 

The #15 hose isn't the source of an antifreeze leak -- it carries sea water to the Hx inlet from your Sherwood pump (or Oberdorfer if upgraded) 7/8" hose barb elbow to the Hx raw water inlet.    It's nothing more than wire-wound water/exhaust hose (e.g.,  SheildsFlex 250 series, p/n 16-250-0780)  Wb makes it sound more complicated than reality.  It will bend as needed, the wire just keeps it from collapsing at bends (or if under a vacuum.)

See the XPB photo below (my 35B photo is not as clear), it's not run exactly as the parts manual shows (again Wb making it more complicated than necessary.)

Hose #16 is indeed formed, and returns antifreeze from the Hx outlet to the coolant pump.  Possibly it's your source of antifreeze.  The critical bend is the 90 and could be jury-rigged with an elbow.  The last one I replaced was about 46 boat bucks -- I can drop ship you one if you don't want to search it out.  It's 50/50 whether my distributor has one in stock, but if not it shows to be in stock at the factory.  TOAD can't sell it to you (you're outside its Westerbeke dealer territory.)

Another source of antifreeze might be hose #29, ShieldsFlex # 16-250-1180 that delivers coolant from the thermostat, thru the exhaust manifold, to the Hx inlet.

cheers
ken

[Breakin Away]

Thanks, Ken. First I need to do some more diagnosis (and play with hose clamps), but I will use your services if I end up doing the new parts. I have all winter to get this done, and won't start until the temps rise out of the teens.

Thanks for the correction on the contents of the hoses. Your observation is consistent with my observations, since I think the coolant is coming from #16's connection to the HX. But the sketch in the parts manual made it look like #16 was connected to the raw water pump (which surprised me given my observations of coolant drips from #16). Upon looking at additional pictures, I now see that it was an optical illusion.

[Ron Hill]

Breaking : In general a wire reinforced hose is used when the hose makes an acute 90degree turn and the wire is necessary to keep the inside (same diameter) from collapsing/crimping. 
That #16 hose is most likely pre formed as it makes 2 of those 45 degree turns in a very short distance!!

A thought

[KWKloeber]

OK just let me know if you need it. Also, one of the marinas just up bay from you is als a WB dealer as well.   I don't think it would save any money ordering and pick it up there, you're going to pay shipping either to there or to your doorstep.

Anti-freeze wouldn't be coming from the end cap gasket, unless the HX is compromised.

K

[Roc]

Breakin,
Check to see if the leak is "starting" in that area, or is it dripping from that area due to a leak above that traverses down.  I thought I had a leak in around the area you mention, until I noticed evidence of dried antifreeze near the pressure cap.  Turns out it was dripping from the cap and the fluid dripped down the engine and onto the base at the rear location.  Our engines are basically the same age and those pressure caps do wear out.  I ordered a new cap ($14 including shipping from Hansen Marine) and it seems to work.  So check the area around the pressure cap and the hoses on the upper area of the engine that carry antifreeze.  Another location were I had a leak years ago was those two small 90 degree bend hoses that lead to the HW heater.  They had cracks and needed replacement.  You might want to check those as well.

[Breakin Away]

I will, of course, re-check everything again. But I've gotten in the habit of running a dry paper towel along the bottom of all hoses, manifolds, HX, and drain plugs to see if the leaks originate "uphill" from the low point where it's actually dripping from. I also strategically place paper towels in various areas, and wrap them around hoses and fittings. Last winter I quickly found that the leak was coming from the front of the engine and running down the bottom of the manifold. Easily fixed by tightening a hose clamp. This year, so far, everything that I can reach has been dry except right below the aft hose connection. I think my next step will be to remove the engine compartment in the aft berth so I can get better visibility for diagnosis and access for repair.

[KWKloeber]

BTW while you're in there, upgrade all your clamps to ABA or AWAB.  I did EVERY clamp on my boat.

k

[Stu Jackson]

>>>>>>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
I think my next step will be to remove the engine compartment in the aft berth so I can get better visibility for diagnosis and access for repair.

Some skippers have reported installing a large Beckson plate in the vertical face, instead of completely removing it.  This may have been on Mark I boats.

IIRC, from a friend's Mark II boat, that once the aft cabin cushions are removed there is very good access to the rear of the engine back there.

Good luck.

[Breakin Away]

Time for me to circle back to this thread. After traveling for a couple weeks, I returned to the boat today and confirm that I have fixed the leak. The leak turned out to be near the front of the motor (and traveled down the bottom of the manifold), and was easily fixed by tightening the hose clamp.

This was the exact same leak I had last winter. I missed it because it took a different path than before.

Moral of the story: Don't get too creative in looking for leaks. It could actually be the same thing that happened before.

Second moral of the story: Set up a PM schedule for things like this.

[KWKloeber]

Moral of the story: Don't get too creative in looking for leaks. It could actually be the same thing that happened before.

Second moral of the story: Set up a PM schedule for things like this.

3rd moral ----  replace those perforated-band clamps with ABA/AWAB style!!!!