I have developed a coolant leak from both the front and the back on my coolant manifold. I have purchased all new gaskets and hoses and would like to think that this is a low skill level repair that I can attempt for myself. The front looks like a pretty straightforward repair and is even easily accessible. The back is going to be a lot harder for an old guy like me to get at, but the thing I don’t see an obvious method to remove is the solid metal pipe (the middle piece of the three connections at the back of the manifold shown in the attached picture) connecting the manifold to the exhaust system.
The parts manual shows it as a “nipple” - a straight piece of pipe threaded at both ends. Can anyone tell me how to get this apart? I am hoping that one of the ends is reverse threaded so that I can try and loosen up the exhaust system to get a bit of play, put a pipe wrench on it and screw it out. Is this how it works, or am I going to have to disassemble the entire exhaust system to get the back off of the cooling manifold to replace the gasket?
I’m not much of a mechanic, but I’m trying to learn! Here’s hoping that older and more experienced heads than mine can provide some guidance here. Any advice will be greatly appreciated.
Starting to wonder if this Covid-19 thing is going to affect our launch date here in Toronto. It is the one day that virtually every member of our club will be crowded together for most of the day. Will make it kind of hard to do the social distancing thing.
Hi Ralph,
The pipe you indicated is the exhaust riser. The other end of that pipe typically connects to a rubber exhaust hose held on with two hose clamps. The injection elbow/fitting will be in the area near the hose clamps. If that is the case, remove the hose clamps and disassemble the threaded joints one by one, using two pipe wrenches, until you have disassembled everything back to the manifold.
Alternately, since this piping should be replaced every 5 years or so, cut the pipe with a hacksaw or reciprocating saw several inches from the manifold. Then use a pipe wrench to remove the nipple from the threaded plate.
As a second alternate, remove the two water connections from the plate,remove the plate from the manifold and work on the exhaust pipe away from the engine in a convenient location.
Some hardware stores can supply/fabricate replacement pieces.
Take the entire manifold off and work on it at a bench. Those risers will need heat and penetrating oil to bust out. Make sure when you reattach the ends you use a torque wrench to snug them up.
They are simple pipe and you could get one fabricated in stainless steel. Use lots of anti seize upon reassembly.
I agree with Thor. Start soaking the nuts and any other fittings to come apart now. Do not force those nuts or studs. Be patient. Anything that is rusty or old – replace!
Joe Valinoti
S/V IL Gatto NS30U #221
Sea Harbour YC
Oriental, NC USA
That center hose is held on with EAR clamps. It is just a different type of hose clamp it is put over the hose and then crimped with a tool to squeeze it into the hose. https://www.mscdirect.com/product/details/48544084?fromRR=Y. They have to be cut off. You cut the top part of the ear and then push it apart.
I will probably have to do this repair as well soon.
Peter, the ear clamps just hold some insulation around this nipple. This part threads into the extrusion on one end.
Ralph, the part you don’t want to damage and replace is the two pass exhaust manifold extrusion which is listed in the parts as Manufacturer: Westerbeke Part Number: 35362 Description:
Exhaust Manifold ASSEMBLY
Part #35362 from Westerbeke
I suspect this is the whole assembly with end ends on. But in any case all the other bits are studs and nipples and flat plates that you might be able to reuse after cleaning or buy locally. Just don’t damage the extrusion.
I’m suggesting you try and remove the whole assembly from the engine rather than trying to fix the end gaskets in place. The front is not so bad but the back one will be very difficult.
So if you are replacing the hoses (and yours look very old you probably will) you can cut these. I replaced the water hoses a few years ago and the new ones fit fairly well.
Try to remove, don’t cut, the hoses from the injection elbow, your photo doesn’t show the rest of it but if it is like mine there are two nipples and two elbows here up to the water injection elbow (wrapped in insulation(asbestos?)). They go higher than in the parts diagrams. These are rusted together nicely.
Now there are only four 5/16 nuts holding the 2 exhaust manifold elbows to the extrusion. These are underneath and may be hard to get at.
You can work on the manifold on a bench now and are far less likely to damage it. Like Joe says soak the nuts and studs before you try and remove them and go slowly.
You may need two new: Manufacturer: Westerbeke Part Number: 24662 Description:
Exhaust Elbow Gasket
Thanks for the replies guys. I guess I am going to have to make another trip back down to the boat and reassess the situation. See if this is a can of worms I really want to open on my own.
Tom - where are you getting your parts from? I just paid $9.40 each for part #24763 which looks pretty much identical to the part that you mention. They go with the hose connectors at the front and back of the manifold. What is the manifold made of anyway? Isn’t there going to be a problem with electrolysis if you start inserting SS bits into the mix? Some of the nuts holding on the various bits of my manifold are pretty rusty. I had the thought of replacing them with SS, but then figured I might be adding a corrosion problem with mixed metals if I did. As you can see, you are dealing with a very inexperienced owner here. I’d like to learn to do it myself, but I also don’t want to wreck a bunch of expensive parts due to incompetence.
It is actually an easy fix, but as Joe says go slow. A 50/50 mixture of transmission oil and acetone is a great penetrating oil. And there is a penetrating oil product that freezes the bolts vs uing a torch that I found worked well on an old car I was restoring. Prevented me from burning it up with a torch
I bought the Westerbeke parts from Anthony Keats marine here in Ontario. I thought I should support the local guy since I might need him in the future. Anthony was always helpful and answered questions.
I see the Westerbeke site has the bare manifold, not as an assembly: https://www.westerbeke.com/Product/MANIFOLD/024298
It is an aluminum extrusion with various holes machined and tapped into it.
This photo is of the bottom of the manifold.
I will have to pass to someone more knowledgeable on this list about if it’s OK to use SS in aluminum. I know there are SS bolts and nuts all over the aluminum mast with no corrosion that I can see. Of course I’m in fresh water and that should make a difference. I think we talked about this on the list before and the answer was SS in aluminum was OK but you should use an insulating compound on the threads. Not sure if this applies to the engine.
As far as experience, this part has lasted almost 40 years, after I rebuild it I expect it will be the last time.
When I disassembled mine the bolts were plain steel. Stainless is not really required here, just use anti seize on the bolts. You will not see much evidence of AL - Stainless corrosion on the mast until you try to take it apart. Mike Q uses Tough Gel and hear it is very good at preventing stainless issues with AL.
Teff Gel is the way to go for any stainless bolt or machine screw mounted thru aluminum. Good examples are stainless bolts thru the mast base and on the Edson pedestal, the machine screws holding the upper pedestal section to the base.
Ken Dakin
Hi Ralph
I was at the boat yesterday to check on the tarp and take some photos.
I looked at the photos just now and can see leaks on this exhaust manifold. I’ll start buying parts to make the repair as well.
And clear evidence of a drip from the back as well. The bad news is that back exhaust elbow stud (in the dark crack just just aft of the intake “silencer” ) is very hard to get at and might mean the intake will have to be removed. There is a slight chance that a long skinny socket will get on this nut - I will try it next time I go to the boat. Looks like I may have some spare time in the next month or so.
You can get a pressure tester at most auto parts stores on loan. I would test it before I started undoing everything. If you have to redo it , removing the whole assembly from the boat would be an easier way to go. The bolts to the engine I think are metric. The cooling box are sae.
With this lock-down in place I’m having a hard time motivating myself to even go down to the boat. It’s starting to look very much like we may not even have a launch this year. On top of that I’m reluctant to tear the engine apart and not be able to get the parts to put it back together in case we actually do do a launch. The local Westerbeke parts supplier is closed for the foreseeable future due to the virus.
The only part I’m currently missing is one gasket. I remember from my youth whenever my father needed an engine gasket he would trace the old one on a sheet of cork he always had laying around the workshop and cut a replacement. Any reason I can’t try the same thing?
Thor: My cooling system would probably pass a pressure test - there is just a couple of slow leaks from the front and back of the manifold that amount to a few drops a day. I can’t even pinpoint exactly where they are. It’s just that I am putting the boat up for sale and don’t want a surveyor pointing out that the engine has a coolant leak. Also; I don’t see the problem getting any better over time, and if it should suddenly get worse it will undoubtedly be at the worst possible moment.
Tom: It looks as if your manifold is configured the same as mine - with the hose at the front of the manifold coming out on the port side and heading off to port. The parts manual shows just the opposite configuration. The parts guy didn’t seem to think that this was anything to be concerned about, so let’s just hope that he is right. Does your heat exchanger have a valve to drain coolant at the bottom of the port end? Mine just has two bolts. I assume one is for coolant and one is for lake water, but I have no idea which is which.
Hi Ralph
That’s a bit bleak, not having a launch this year at all. My wife will be very disappointed if she had to have me here all summer.
I tried to contact my Westebeke guy as well and no answer.
I think you are right, all these bits on the manifold are flat metal, standard bolts and studs a plugs and the gasket material can be cut out of something. I have used the Permatex gasket in a tube on my fuel tank and it worked very well. Now you can buy all kinds of this gasket in a tube stuff for different applications.
I am not a machinist so the two rusty cover plates will be a challenge to make.
The drawing is for a 13-18-21-27 and 33. On a 13 the intake and exhaust valves are on the same side of the head, on the others the intakes are on the left and the exhausts are on the right. So the manifold on the 13 is on the opposite side of the engine from all the others. The drawing is for all the engines and they just took some shortcuts with the drawing.
The Heat Exchanger has a standard radiator petcock on the port end. Just as explained above, on the 13 the heat exchanger is reversed left to right. In the drawings it is shown on starboard as it would be on the 18-21-28… so I can see your confusion. This drain cock is below the ZINK and next to another little plug but I don’t remember what that was for. It is not coolant though, it is in the raw water same as the raw water zink and petcock.
