Rich:

Just a thought. If this was my boat and having that same trouble. What I would do is remove the bilge cover and place it to the side. Then take and remove the engine cover and place it over the bilge area as it is a place I store mine when working on the motor. Now you have a open bilge and a open engine area. Now I would go out sailing with someone as you just did if you can and try and recreate the same thing as your down below looking for the water intrusion. I know i is very frustrating in what you have. Hoping that you can find it this way.
Randy

Any chance your raw water cooling system is leaking where it enters the aqua lift muffler? That has happened to several of us recently. It gets worse the higher you rev the engine.

It was driving me crazy trying to figue out where the water was coming in from. When I pumped the bildge dry at the dock and left it overnight no water came in. When I ran to engine the water came in. Even after I shut the engine down it would still trickle in for a short time. Duane told me to check the aqua muffler and I found that is where my leak was, at the bottom of the hose going into the top of the aqua muffler. Just looking in that area I could not see it when the engine was idleing, but when using a bright flashlight, not one with half dead batteries, I could see the leak and if I increased to engine speed the water came in faster and was easy to see.

I can cut the hose off but the new hose is to short and to stiff to bend. I can't figure how to replace the hose so I called a mechanic who will be coming to make the repair on Wednesday at $95 an hour.

Mike, there are two hoses at the muffler, in from the engine and out to the exhaust. You should have a hump hose on the inlet (blue softer material) and standard exhaust hose on the outlet. I replaced the first few feet of my exhaust hose and used a coupler (MMC EL-158-0045 45 deg. 1 5/8" fiberglass) between the two pieces with hose clamps. I have over the years re-built-up the flanges on the muffler, and need to better re-fair them to avoid the leaks. Unless you're just not into tools, this is not something that's worth spending $95 an hour for.

You can also get water back into your bilge when under (high) power because the stern swats. Our bilge through hull goes under water over 6.2 knots.

Stu
Thanks for your suggestions. I have a different engine than you, Mine is a M-35. I Don't see any blue material on my exhaust system, I have white material but this is not the hose that is leaking. The hose I am talking about is black, about one foot long with double clamps on both ends and comes off the pipe with the white insulation into the aqua muffler.

When I motor with a RIB inflatable hanging on davits off the back of the boat I may going over the exhaust at a slower speed. That is why If I am going a on a long trip I usually put the inflatable on the forward deck.

The hump hose is one of the most appropriately-named parts on a boat. And it is the correct hose to use on INLET to the muffler on the C-36. The construction of the hose, with the hump, allows it to flex, thus isolating the large vibration transferred from the engine via the rigid exhaust riser. Hump hoses are blue in color, thus the reference in the earlier post.

Larry
In your photo you show a blue hose going into the muffler from a hose wrapped in what appears to be foil. The foil wrapped hose on Caprice is wrapped in a white material and I am guessing that is the same hose. The blue hose you show in the photo is not the same as on my boat. My boat has a straight black hose with no buldge. Could this black hose not be the correct hose that belongs in the place of the blue hose?

What appears in my photo to be wrapped in insulating foil is not a hose; it is a cast iron or stainless steel (depending on age of boat) riser, which is a metal, very rigid 'duct' or 'pipe' that carries exhaust from the engine to the muffler. At the inboard end the riser is hard mounted to the engine. At the other end of the riser, farthest from the engine, there is a small tube joining into the riser. This tube is where the water from the heat exchanger enters, and is mixed with, the exhaust flow. Then, the output end of the riser mates with a large diameter hose to connect to the muffler. Ideally, this large diameter hose (a stiff, straight black hose on Mike's boat) should be a hump hose.

A hump hose is the proper connection to the muffler because it has a 'longitudinal flex' (the hump) that isolates harsh engine vibration from the muffler. Any boats with the stiff, straight black hose should certainly be retrofitted with a hump hose. The noise and vibration level in the boat when motoring will improve significantly if a hump hose is used. I purchased my hump hose (plus a spare) from Catalina Direct.

Rich's water leak could be at one of several points in this area, listed in order of probability: 1) Most likely, it is in the hose that runs from the heat exchanger to the mixer inlet on the riser. In my photo, this is the green/black hose that curves around in the upper right corner of the photo. Of course, the leak could be at any point along the length of the hose, so a leak may not be immediately visible just near the riser. 2) Less likely, the leak could be in that straight black hose, as on Mike's boat, but I think one would be aware of exhaust leaking if that hose were damaged. 3) The leak could be in the riser itself, I suppose...but not likely. Again, you would probably be aware of exhaust leakage. And/or 4) it could be a damaged muffler, but exhaust smell might be noticeable in this case also. (Caution: I needn't say this - but I will anyway - that any exhaust leak is dangerous.)

The system is fairly simple; it's not rocket science. Troubleshooting & repair, and installation of a new hump hose, are probably well within the abilities of the average do-it-yourself-er. Access on my Mk II is straight forward; but the Mk I boats may have more difficulty. Mike's 1990 should be similar to mine, I think. Rich's hull #1670 ditto. Any Mk I owner considering a similar problem on their boat should ask Steve Frost for insights, 'cause I don't know those boats' layouts.

I hope this helps.

(BTW, the reason my photo is blurry is because the engine was running when I took the shot.)

Great info, Larry.

1. Mike's Caprice is not hull #1990, but year 1990.
2. I agree that a water leak would not likely be in the exhaust gas portion of the system and that it should be readily apparent from the odor.
3. I had the raw water coolant hose connection fail on mine due to a corroded clamp. It was an easy fix.

Of course, Duane, your mention of hose clamps is very appropriate. Clamp tightness should be the very first thing that is checked. At every oil change (time permitting), with a couple of the right sockets in hand and/or a couple screwdrivers, go all around the engine area and make sure every clamp that is within sight/reach is snugged up. Not bar tight...but firmly snug.

(Re the technical terms 'bar tight' versus 'firmly snug,' we will just have to await Steve Frost's definitions.)

Good point, Larry.

'Too tight' on hose clamps is not better than 'tight enough.'

Also, not all hose/fitting assemblies should have double clamps. Ideally, the hose fitting is long enough to have 2 clamps compress the hose against the fitting inside the hose. If the fitting is too short, the extra clamp will put undue stress on the hose and could make premature failure MORE likely.

Like so many things, a hard and fast rule is not always available.

Good points all, leaks can be elusive.

Rob had noted that his leak was at its worst at or above hull speed and was more pronounced when motoring. This led many here towards engine our cooling system leaks and I would agree. Along with the aqua lift muffler and associated hoses and connections I would scrutenize the heat exchanger for leaks at the end caps and at the zinc plug on the bottom. It is not uncommon if leaks occur on the hoses going to or from heat exchanger or any water hose for that matter for the water to run down the hose making it hard to see the drip as the water will run along the bottom of the hose and not drip off untill the hose makes contact with something. Wraping your hand or a tie wrap around the hose will cause the water to drip off your hand or the tie wrap making it more obvious.

The other thing that occured to me is his mention of this occuring at or above hull speed. When motorsailing on my boat the stern does squat a bit and with any heel the exhaust exit at the hull and the lee cockpit scupper become submerged. The scupper drains are often overlooked at the dock as they are above water line when the boat is level and seldom get much attention. Just a thought.

As for the term bar tight, if you find yourself in this condition it best that you have a designated driver.

I have a 1989 and probably similar configuration to the 1990 version. I replaced the old black exhaust hose with the blue hump hose.

Due to the space constraints, it was IMPOSSIBLE to use the black exhaust hose type- gotta be the FLEXIBLE blue hump hose!

The white wrapping is just an insulating wrap. If you take that wrap off, there is a wire mesh (CAREFUL it can have lots of sharp edges). There will also be VERY MESSY fiberglass insulation! Use the proper precautions, as you would for any job involving fiberglass (don't ask me how I know that!)

Be prepared to do a thorough vacuuming clean up if the fiberglass gets around.

Laura Olsen

Larry

Thank you for your advice on what had to be done to replace the exhaust hose.

No one in SW Florida had the proper blue hump hose to replace the solid black hose from the riser to the aqua muffler on Caprice. I had to order it from Catalina Direct and it took a week to recieve it from across the Country. Meanwhile, I duct taped the black hose which slowed the leak. This is something to remember if the problem happens while under way.

I could not do the replacement job myself because of my physical limitations. It is a bitch watching someone else doing a job on my boat that is something I could have done myself a few years ago. Especially at $95 an hour. The mechanic finished the job a few minutes ago and now I can go sailing without filling up my bildge with sea water. "Life is Good Again."

I wondered why our harbor depths were so low lately. All the water was in Mike's bilge!

Mike, glad to hear you have resolved the problem. So the leak was in the hose, then??

Larrry
Yes, there was a small split in the black house on the opposite side from which the hose could be viewed. When I saw the leak with the engine running I thought it was lose clamps becasue I could not see the split so I checked the tightness of the clamps. When I realized that was not it, I put my hand around the hose and could feel the split.

I have always wondered why your face was blurry, wasn't sure if it was from alcohol or what.....

I have water in the bilge of my 87 Catalina, Last Resort. I am attempting to identify the source and believe it be at the anchor locker as I also have some water in the forward berth area after a heavy rain.

My question is this. When I turn on the bilge pump, it does pump out some of the water, etc. However, when I turn off the bilge pump, a lot of water backs back into the bilge.....frankly at times it looks as though more returns into the bilge than was pumped out?

Thoughts?

Thanks!

al:)

This is a feature, it is the BDMS, Bilge Dust Mitigation System.

It is caused by the fact that the bilge pump outlet is above the water line about twelve feet away from the pump, when the pump stops Mr. Gravity causes all the water in the 3/4 inch hose to run back into the bilge. It sometimes looks like more water comes back in due to the fact that as the bilge pump emties the bilge water is slowly draining from the forward bilge compartments through the limber holes in the ribs back to the bay the pump
is in. When the water runs back into the bay the pump is in it looks higher until the water level evens out in all the bays.

We may ask if anyone here has installed a check valve in the outlet line to keep the water from running back into the bilge and did it work. My assuption is that the check valve would eventualy get gunked up and allow water to trickle back to the bilge anyhow.

Steve makes a very good observation about the water equalization between the limber holes.

Unless you could guarantee a perfectly-functioning check valve 100% of the time, they are a bad idea. They do slow the rate of waterflow through the hose somewhat, and they can gunk up and fail in the closed or partially closed position, which is really bad.

Better is the scheme Tom Soko employed. He added a smaller bilge pump and hose to get the lower levels of water and leaves the big pump to handle the higher levels. The smaller hose allows less water to drain back in.

Al,

If you go to the C36IA homepage and click on the Technical tab, then on Upgrades, you can look through many pages of possible upgrades that we have made to our C36s over the years. On the third page or so, you'll find Tom Sokoloski's excellent article on installing a second bilge pump. Of course, you must be a Member (capital M) of the C36IA to access our valuable technical archives.

Larry, Duane and Steve,

Thanks much for the insight and explanation. Seems to make sense to me. I did run the bilge this pm and did not see any water discharging from the drains. I wonder if the bilge water is being pumped into the pipe, but not exiting? Any creative thoughts on cleaning out the drain piping, etc.

Larry, thanks for the big'M' pitch. I am going to do so.Thanks!

al

I put in a check valve immediately after the pump. However, because of the head of water trapped above it, the pump then did not have a high-enough discharge pressure to overcome the combined head plus spring tension of the check valve. I removed the check valve, and have learned to put up with the couple of litres of bilge water that is returned after pump shutdown.

Thanks Sarah.

Update: Cleaned out bilge, etc. Took her out in very light winds on Saturday. Upon returning, the bilge had perhaps a half cup (4 ounces) of water in it. The water appeared to be coming from forward and in some respects appeared to surround one of the forward port keel bolts. Thoughts?

Also, separate question. I installed a Vacu-flush (love it). However, I noticed that in the head/shower area there is a small compartment, forward of the sink, below seat. Inside there is a valve with a 'T' sharpee diagram below it. Not sure what this is? Thoughts?

Thanks!

al

Al,
Would it be possible to attach a picture to your question? Is the sharpee diagram on the hull? On a plastic label?

Also, please help us help you. Please modify your "signature" to at least include a hull number. Early and late '87s had some differences.

Tom,

I will do so. Make take a day or two as I am traveling at this time. In sum, the 'T' is a heavy black Sharpee (felt pen) drawing located next to a valve/pipe fitting. The valve, drawing, etc are located in a small enclosure in the head, behind a teak cabinet door, located under the shower seat. The 'T' appears to be attempting to indicate 'open/closed', though I cannot tell for what purpose?

Thanks!

al

As with Tom's suggestion, we do not know the vintage of your boat, this may help narrow in on the issue.

On my 1988 vintage there are two valves in the location you indicate. one is for the raw water intake for the toilet if using raw water for flushing. The second is for the sink drain, this one is important to know about and inform guest of its location and use for the following reason. When our boats heal heavily on starboard tack the level of the sink in the head can go below the water line. This allows the sink to fill with water and slosh out onto the back wall of the head compartment and run into the bilge. For this reason it is important that you guest and crew know where this valve is incase you are on a long starboard tack and healing they will need to shut this sink drain seacock off to limit the amount of water shipped aboard.

It seems to me that the main issue is not the bilge pump but the source of water, as alpace says that there is water that evidently is coming from the anchor locker. If that is where it's coming from, the leak needs to be identified and fixed so as not to cause damage. Can you get a friend to take a hose and slowly run water over various possible leak points in the anchor locker, starting with the lowest one and moving upwards while you watch from below?

We had water coming in from the anchor locker area on our 28. On closer examination it turned out the anchor roller had never been bedded at the factory and there was a gap between it and the stemhead fitting that let water run down the inside of the hull and into the bilge. Bedding the anchor roller and filling that gap fixed it. Might be something to check into.

Steve,

Thanks for the clarification. I think you are correct. The valve permits seawater in rather than the fresh, etc. With new vacuflush the head never had any odors, etc. When I turned the valve on our last outing, I noticed a definite sea odor, etc. At the time, I attributed the odor to the water in the bilge. My bet is you are correct and I will check this weekend!

Great tip about the sink as well....thanks!

al

Steve,

The above is the boat particulars....

thanks again!@

al

Hey guys,

Thanks for the great suggestions, etc. Hope to work on the boat this weekend, etc.

I cleaned out the anchor locker and found a) the drain was plugged and the line and rode were wet. I replace hatch door seals, cleaned out drain and followed a members suggestion of spraying insulating foam in the crevice where the nav lights enter as well as in the 'seam' where the hull deck meets the anchor locker. We have had a bunch of rain here for the last few days, so this weekend I should be able to evaluate whether these attempts to fix have proven effective. I am also going to take a look at the roller bedding.

Really appreciate all of the input. REALLY HELPFUL!!

Cheers!

al

Al,
I agree with all the things you did, except "replace the hatch door seals". The anchor locker has a drain, and by design the forward end of the anchor locker has an opening for the anchor rode, so I see no reason to have any seals on the hatch doors. It's impossible to keep water out, so why mess things up with seals? Maybe I'm missing something??

Your logic kills me! ;-)

Of course what you are saying is correct, that said the rubber gasket seals were already there! perhaps my father installed them in an effort to stop the leak? Perhaps the are simply sound dampeners for the doors? Now I am puzzled!

Al