All, I noticed a coolant leak on my engine, but I am not sure of the source. I have a very slight stream dripping down into the bilge right where the transmission mates to the engine, and it does not start until the engine is heated up and the coolant has a little pressure. As far as I can tell none of the hoses are loose and leaking and from the top of the engine there is not indication at all of coolant leaking. Only other thing there is the heat exchanger, which again from visual inspection does not appear to have a leak. Any ideas on where I should look next?
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Somewhere on the port side...
...of course, because it is hard to see and impossible to reach! I have the same problem and others have reported similar symptoms as well. And the strangest thing is that mine, and others too, only leaks when the sea water is cold. It will leak in the spring months, but not at all during the summer, then returns to leaking during the fall! A couple owners have reported that the source of the leak was on the port side of the engine and, if I remember correctly, had something to do with a petcock on the engine block. I've still not been able to track it down though, but I have to admit that I haven't tried very hard. Please let us know if you find a solution. Mark
...of course, because it is hard to see and impossible to reach! I have the same problem and others have reported similar symptoms as well. And the strangest thing is that mine, and others too, only leaks when the sea water is cold. It will leak in the spring months, but not at all during the summer, then returns to leaking during the fall! A couple owners have reported that the source of the leak was on the port side of the engine and, if I remember correctly, had something to do with a petcock on the engine block. I've still not been able to track it down though, but I have to admit that I haven't tried very hard. Please let us know if you find a solution. Mark
Will check for the petcock.
What concerns me is that the water is fairly warm now. I will look for a petcock on the port side. Figures it would be on the port side. I will let you all know what I find. Any chance that would be shown in the manual?
What concerns me is that the water is fairly warm now. I will look for a petcock on the port side. Figures it would be on the port side. I will let you all know what I find. Any chance that would be shown in the manual?
Leak from hoses
Hello All. I suffer from the same problem. I would operate the auxiliary with no problems or leaks. After shutting down and leaving the boat for a day or two I would return to find coolant in the catch-all below the engine and the level in the reserve bottle down slightly. I bought a tester and pressure tested the system. It held the pressure. I have inspected the engine and still have not 'found' the leak. However, while travelling to my family home in the Magdalen Islands by ferry I met an old friend that is a diesel technician that also owns a boat. He told me to check the hose clamps on the hoses. I told him that I have tightened all of the clamps without success. He then asked what kind of hose clamps I have. I told him standard worm-gear hose clamps (jubilee clips for some I think). He suggested that I may have a cold leak from the hose clamp. He advised that they have had this problem with some trucks for years. He says the worm gear clamps do not tighten uniformly around the hose/barb no matter how tight you make them. He says that with his trucks, he when he suspects this is the problem, he replaces the offending clamp with one that is designed for silicon hoses. Apparently these clamps do tighten uniformly around the 360 face of the hose/barb. I have not yet tested his theory. I certainly respect his experience and knowledge. I do believe one or more of the hoses were leaking. Also, I thought my cap may be leaking. The reserve bottle will drop to the level of the cap but no further. It is frustrating. Also, I am certain the brackets on my HX may be cracked. I am looking at changing this myself sometime soon. From what I have read in this and other forums, this HX problem is a constant. Regards Chris
Hello All. I suffer from the same problem. I would operate the auxiliary with no problems or leaks. After shutting down and leaving the boat for a day or two I would return to find coolant in the catch-all below the engine and the level in the reserve bottle down slightly. I bought a tester and pressure tested the system. It held the pressure. I have inspected the engine and still have not 'found' the leak. However, while travelling to my family home in the Magdalen Islands by ferry I met an old friend that is a diesel technician that also owns a boat. He told me to check the hose clamps on the hoses. I told him that I have tightened all of the clamps without success. He then asked what kind of hose clamps I have. I told him standard worm-gear hose clamps (jubilee clips for some I think). He suggested that I may have a cold leak from the hose clamp. He advised that they have had this problem with some trucks for years. He says the worm gear clamps do not tighten uniformly around the hose/barb no matter how tight you make them. He says that with his trucks, he when he suspects this is the problem, he replaces the offending clamp with one that is designed for silicon hoses. Apparently these clamps do tighten uniformly around the 360 face of the hose/barb. I have not yet tested his theory. I certainly respect his experience and knowledge. I do believe one or more of the hoses were leaking. Also, I thought my cap may be leaking. The reserve bottle will drop to the level of the cap but no further. It is frustrating. Also, I am certain the brackets on my HX may be cracked. I am looking at changing this myself sometime soon. From what I have read in this and other forums, this HX problem is a constant. Regards Chris
Have you considered the age of your hoses?
In addition to the clamps, older hoses start to deteriorate from the inside out, too.
In addition to the clamps, older hoses start to deteriorate from the inside out, too.
The manual probably does illustrate it...
I think the petcock may be illustrated in the manual. I can't remember for sure though, because it's been a while since I've looked into this problem. There are also some diagrams on marinedieseldirect.com. Chris, you should talk to someone at Universal about your heat exchanger problem. It's been an epidemic, and I think they will supply you with new brackets and perhaps the whole exchanger. They redesigned the brackets where they now wrap all the way around the exchanger rather than being brazed together.
I think the petcock may be illustrated in the manual. I can't remember for sure though, because it's been a while since I've looked into this problem. There are also some diagrams on marinedieseldirect.com. Chris, you should talk to someone at Universal about your heat exchanger problem. It's been an epidemic, and I think they will supply you with new brackets and perhaps the whole exchanger. They redesigned the brackets where they now wrap all the way around the exchanger rather than being brazed together.
Did look at the hoses
Stu, I did look at all the hoses. From what I could tell from a quick look there are only 2 hoses that are of concern for the coolant. Naturally, they did appear to go into places where they were hard to trace, but I was able to run my fingers under each and did not detect enough moisture to think they were the culprits (the leak is now fairly obvious). Good news is the leak does appear to be on the back side of the engine so my possibilities are a bit reduced.
Stu, I did look at all the hoses. From what I could tell from a quick look there are only 2 hoses that are of concern for the coolant. Naturally, they did appear to go into places where they were hard to trace, but I was able to run my fingers under each and did not detect enough moisture to think they were the culprits (the leak is now fairly obvious). Good news is the leak does appear to be on the back side of the engine so my possibilities are a bit reduced.
Ray, the link shows what happens
when you only look at hoses. Ya gotta feel them and also know how old they are. While the story is about hoses to the HW heater, and not the HX, the concept's the same. They "looked good" where I could see them, but they were toast inside. And, based on the age, the connections start going, too.
when you only look at hoses. Ya gotta feel them and also know how old they are. While the story is about hoses to the HW heater, and not the HX, the concept's the same. They "looked good" where I could see them, but they were toast inside. And, based on the age, the connections start going, too.
Confusion about M-25XP and XPB HX
Hello all: This is likely repititious but I have to ask: I am looking at the on-line parts manual for the M-25XP from the link provided by Stu and I have the 11B, 'New Style' heat exchanger. The brackets do not go all the way around the HX. However, I have the M-25XPB engine installed (or so I believe). I notice that on the on-line parts manual for the M-25XPB the heat exchanger brackets go all the way around the HX. Perhaps I am mistaken and I do not have this model Universal? I have a 2002 model Catalina 310. In the case of the M-25XP 'New Style' HX - are the brackets brazed on? I have sent an email to the manufacturer a week ago but have not received and answer. Regards Chris
Hello all: This is likely repititious but I have to ask: I am looking at the on-line parts manual for the M-25XP from the link provided by Stu and I have the 11B, 'New Style' heat exchanger. The brackets do not go all the way around the HX. However, I have the M-25XPB engine installed (or so I believe). I notice that on the on-line parts manual for the M-25XPB the heat exchanger brackets go all the way around the HX. Perhaps I am mistaken and I do not have this model Universal? I have a 2002 model Catalina 310. In the case of the M-25XP 'New Style' HX - are the brackets brazed on? I have sent an email to the manufacturer a week ago but have not received and answer. Regards Chris
Don't confuse the two engines...
Chris, I may be mistaking, but I believe you probably have the M-25xpb. I believe that is the only engine used in the 310's except for a few of the earliest hulls were they install a Yanmar(if I remember right). So don't pay any attention to the HX in that xpa, cause they're completely different. The 11b part you see on the xpa was not a redesign to address bracket issues. It sounds like you have the original HX for the xpb, which is very similar to the 11b from the xpa(probably not a coincidence). And that's probably why it got confusing. The link below is for the HX on the xpb.
Chris, I may be mistaking, but I believe you probably have the M-25xpb. I believe that is the only engine used in the 310's except for a few of the earliest hulls were they install a Yanmar(if I remember right). So don't pay any attention to the HX in that xpa, cause they're completely different. The 11b part you see on the xpa was not a redesign to address bracket issues. It sounds like you have the original HX for the xpb, which is very similar to the 11b from the xpa(probably not a coincidence). And that's probably why it got confusing. The link below is for the HX on the xpb.
Replacing the original HX with latest HX - Universal M-25XPB
Thank you all: I am inclined to believe that I have the m-25 XPB. The user manual is for that engine. The heat exchanger however does not look like the exchanger from the parts manual for the same engine. I am now assuming that the original m-25XPB HX is prone to cracking. Is the replacement HX with the full bracket interchangeable with the original M-25XPB HX? i.e. if I replace the HX can I fit the newer HX? (I knew there was a reason I should have gone marine engineering instead of deck at college!) Regards, Chris
Thank you all: I am inclined to believe that I have the m-25 XPB. The user manual is for that engine. The heat exchanger however does not look like the exchanger from the parts manual for the same engine. I am now assuming that the original m-25XPB HX is prone to cracking. Is the replacement HX with the full bracket interchangeable with the original M-25XPB HX? i.e. if I replace the HX can I fit the newer HX? (I knew there was a reason I should have gone marine engineering instead of deck at college!) Regards, Chris
The new HX is interchangeable with the original...
Changing the HX on your boat is quite a chore since there is very little (no) room to reach the bolts and manipulate the exchanger in and out of its home. So you may want to verify that your brackets are broken before committing to the task.
Changing the HX on your boat is quite a chore since there is very little (no) room to reach the bolts and manipulate the exchanger in and out of its home. So you may want to verify that your brackets are broken before committing to the task.
Ray, that petcock looks ALL WRONG
There should be a pencil zinc there, unless you have one at the other end. If you have NO zinc, you should replace that petcock, which is doing nothing, with a zinc.
There should be a pencil zinc there, unless you have one at the other end. If you have NO zinc, you should replace that petcock, which is doing nothing, with a zinc.
repairing a heat exchanger
You know, there is no compelling reason to locate the heat exchanger anywhere in particular, as long as the hoses reach. I think the only reason its bolted to the engine is because that's the way Universal/Westerbeke supplies the power unit. I have a 1984 C-36 Mk. I. I replaced the heat exchanger a few years ago. I now plan on re-locating it, along with doing away with the Rube-Goldberg coolant, bypass valve. I may just move it to an easily accessible (yacht-oxymoron?) spot under the aft berth. You might want to consider this, to avoid the engine vibrations killing it. jv
You know, there is no compelling reason to locate the heat exchanger anywhere in particular, as long as the hoses reach. I think the only reason its bolted to the engine is because that's the way Universal/Westerbeke supplies the power unit. I have a 1984 C-36 Mk. I. I replaced the heat exchanger a few years ago. I now plan on re-locating it, along with doing away with the Rube-Goldberg coolant, bypass valve. I may just move it to an easily accessible (yacht-oxymoron?) spot under the aft berth. You might want to consider this, to avoid the engine vibrations killing it. jv
Picture of New Heat Exchanger
Universal sent parts guy this. Still waiting on it to come from back order.
Universal sent parts guy this. Still waiting on it to come from back order.
Got the new Heat Exchanger
Finally got the new heat exchanger in. It looks like the one in the picture. It was only $466 from marinedieseldirect as opposed to the $550 one I was thinking of. Got it in place last night. Only problem being, which I suspected before I went to the boat, was that the original bolts are too short. When the two brackets wrap around the heat exchanger they still have a gap of about 1/2" which makes the original bolts too short (not to mention the bolts now go through 2 pieces of 1/8" steel for the brackets). Other than that it is a direct 1 for 1 and a big, IMHO, improvement for reliability.
Finally got the new heat exchanger in. It looks like the one in the picture. It was only $466 from marinedieseldirect as opposed to the $550 one I was thinking of. Got it in place last night. Only problem being, which I suspected before I went to the boat, was that the original bolts are too short. When the two brackets wrap around the heat exchanger they still have a gap of about 1/2" which makes the original bolts too short (not to mention the bolts now go through 2 pieces of 1/8" steel for the brackets). Other than that it is a direct 1 for 1 and a big, IMHO, improvement for reliability.
Re: Leak from hoses
RE; The frustrating Leak,
I too have not had a leak all summer, but as soon as I left it for a couple of weeks this fall, went back and started the motor, I found the coolant level to be down. This also happened to me in the early spring. After twisting and turning my body around the engine the only place that appears to be a suspected place of the leak, is the hose coming from the left side of the heat exchanger to the manifold block. (when facing the engine). I have tightened the worm gear to the point of breaking, which seems to have helped but still fear that it has the occasional drip. I will be exploring those other type of clamps that you friend suggested, in your post.
RE; The frustrating Leak,
I too have not had a leak all summer, but as soon as I left it for a couple of weeks this fall, went back and started the motor, I found the coolant level to be down. This also happened to me in the early spring. After twisting and turning my body around the engine the only place that appears to be a suspected place of the leak, is the hose coming from the left side of the heat exchanger to the manifold block. (when facing the engine). I have tightened the worm gear to the point of breaking, which seems to have helped but still fear that it has the occasional drip. I will be exploring those other type of clamps that you friend suggested, in your post.
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