Heat exchanger

[Hans Grasman]

Hi
Just finished some work on the boat and noticced that both ends of the heat exchanger showed leakage. The end caps wre both cracked and looked like they were cracked already some time ago.
Has anybody experienced this and replaced the caps ?
Looking forward to comments.

[Air Mobility]

Hans
Had the same problem last spring. The fix was easy. The marina store got the end cap for me overnight. I removed the opposite end cap and flushed out the heat exchanger while still attached to the engine. Be sure to replace the end cap seals at the same time. No sense doing the job twice. My engine has about 700 hours on it.

George Fisher
Air Mobility
Hull 158

[Hans Grasman]

Thank you George. I will call the Universal dealer in Ft.Myers tomorrow and maybe I can pickup the parts if he has them in stock.

[Palmettomoon350]

Hans,
My heat exchanger end caps showed some leakage and I took them off only to find one was split. I ordered the end caps (2) from the Universal/Westerbeke dealer and installed them when they came in. I cleaned all the hose connections so I could watch for any further signs of leakage. I then cranked the engine and let it run for about 45 mins to check for leaks etc. All is well in the engine compartment!

Carl Beckmann
Palmetto Moon # 223

[DuncanMcMillan]

I've seen some coolant in the sump and it looks like it's coming from the heat exchanger area so I decided to remove and have it flushed.
Getting the straps off was fine but getting the hoses off was another story due to hardness. Is it common to cut and replace the hoses when you do this since it's only every 1000 hours. The hoses seem to be in good condition.
I noticed George managed to to flush exchanger when still in place with just end caps removed?
My back is telling me it's been a long day.

[wolfe10]

I flush mine myself.

After removing, leave one end cap in place. Fill with 25% Hydrochloric acid/75% water. Leave it only 20 seconds or so.

Flush with plenty of water. Look and see if there are still mineral deposits in the tubes. If so, repeat until it is clean. You will also notice that the aggressive chemical reaction between minerals and acid are diminished.

Flush with plenty of water. Clean end caps and install with new gaskets. Paint if desired.

Be sure to check the straps that hold the heat exchanger for cracks.

Brett

[DuncanMcMillan]

Thanks Brett. Is there a tool to back the hoses off or just muscle?

[wolfe10]

Thanks Brett. Is there a tool to back the hoses off or just muscle?

If they are re-usable, just muscle. If you are going to replace them (a good idea if they are stiff/brittle), use vice grips or pliers to twist them to break them free.

Brett

[KenKrawford]

Duncan, I've had some success removing hoses by heating them first. Use either a hair dryer that gets very hot or a heat gun. If you use a heat gun, be careful not to melt the hose. I've even used boiling water in a pinch.

[DuncanMcMillan]

Thanks Brett and Ken. The heat might work .

[R.B.]

One other suggestion is to use a large screwdriver or flat edge tool and pry from the bottom, or push the hose up the barb. Like a "chinese finger puzzle" when you pull you actually elongate and squeeze the hose so it grabs the barb more, by pushing from the bottom you are actually making the diameter a little larger. Careful not to damage the edge of the hose or the barb. Using a plastic or wooden edge is preferable. Usually a combination of prying, pulling, twisting and heat works.

[DuncanMcMillan]

thanks Ralph. I won't get it done for about 2 weeks but I'll let everyone know how it works out. Tempted to get a young apprentice and let him worry about his back.

[Fat Cat]

A simple zinc replacement turned into a HX removal when I found the previous owner had installed a zinc so long it snapped off inside. The hoses were impossible to remove by pulling, but loosened right off by twisting and breaking the seal. The HX slides out fairly easy through the small side access door. This is when I found the starboard bracket broken and the exchanger was about one third plugged. A local radiator shop returned it to me looking like new: welded and painted bracket, acid-washed HX, created end-cap gaskets, installed shorter zinc and included two spares, and painted the HX for $150.00. Bargain. The hardest part was trying to start the bracket bolts, as the brackets were springy (especially the welded one), the bolts short, and visibility zero. I ended up using zipties and temporarily held the bracket closed until I could thread the bolts.

Bob Walton
Fat Cat
Hull #258

[leigh weiss]

Bob,


I had the HX brackets fail last summer along with the fuel filter bracket.
Rather than welding the cracks and broken pieces, and perhaps inducing more cracks and failures
I called Westerbeke and they sent me replacement brackets for both.
In the package was a thin rubber oval pad (about 8") that is pictured in the parts manual installed between the rear side of the engine block and the HX. Looks like this is used to damp vibration and flex of the HX and brackets. When installed, the HX was tight against the rear of the engine block.
Did you find this rubber pad when you removed the old HX? I did not.
I wonder if this is an upgrade that will solve the bracket problem or the rubber pad was omitted or fell out on my engine.
I also used the zip ties to hold the brackets together to reinstall. I left the zip ties in place for the next time.


Leigh Weiss Brisa #155

[Fat Cat]

You're right... there is a rubber pad shown in the owner's manual, although mine didn't have one installed. I did create two rubber strips to isolate the HX from the brackets a bit, and although they were quite thin, it made re-installing the HX even harder, so I left them out. Ideally, some rubber should go there. I also left the zipties in place. We are new to sailing, and I haven't touched an engine since Grade 9 auto mechanics (about 40 years ago), but I'm learning fast. This Catalina website was one of my better finds... along with the wife. I'll have a look at that fuel filter bracket this weekend; maybe the previous owner had it replaced already.

[DuncanMcMillan]

in replacing the HE after cleaning and pressure test I dropped(and lost) one of the capscrews (part 018813) that hold the brackets in place.............. due to combination of spring tension in the bracket and location. I did find an identical replacement but its an M10x25 not M10x20 as shown in the parts list. The latter would be short.
After various prolonged attempts to install the capscrew whilst compressing the bracket and not having a 3rd hand I used a cable tie to clamp the bracket and took my time to insert capscrew. Don't forget to cut the cable tie before you tighten up with 17mm socket. I'm sure my back will recover.

[TBOT422]

I plan to replace the damper plate on our C350 next month. While I am at it, I've decided to flush the heat exchanger. Originally, I had planned to remove the HE and have it done at a radiator shop.

Brett, I noticed that you mentioned you flush it yourself. My question is how do you do that without having a huge mess of acid solution and flushing water all over the place?

Engine has about 800 hours on it.

Thanks

[wolfe10]

Gary,

To flush, I remove the heat exchanger from the boat and remove only one end cap. Fill from the other end with acid solution, Dump in plastic tub to be placed back in acid bottle when finished. Rinse with water-- that water is OK to pour on bare dirt. Repeat another time if you still see mineral deposits.

I would NEVER consider doing this in the boat.

Brett

[TBOT422]

Sorry Brett, I didn't read your previous post carefully. I had just watched a video of some guy cleaning the heat exchanger on an engine with a stainless steel rod much like you would clean a rifle and just jumped to an assumption.

Your description sounds simple enough, but I think I will see what it costs at a radiator shop just for comparison. My guess is that they will also pressure test it as well.

Thanks

[Flagmanmike]

3/2/16 I bought FlagShip, hull 314, about 10 months ago and am just getting adjusted to salt water boating. I'm in Apollo Beach, Tampa Bay. I noticed the same coolant leakage and corrosion product around the HX ends. I have removed the end caps and seals and 0-rings. The seals have elongated dimples, I'm wondering if anyone might know what the dimples are for?

The zinc had essentially disappeared. I don't know how long it's be gone, but I'm wondering what issues I should look for because of this, besides replacing the zinc. I still have to remove the HX to clean and replace hoses, and perhaps it broke off and is in the HX. I'll look this week.

3/3/16 I inspected the starboard chamber of the HX and found 4, count them 4, broken off zincs, large and small. I'm thinking that the left over broken pieces caused the last nearly whole zinc to break off by jamming either during disassembly.

Can zincs just laying in the HX provide protection also?

3/3/16 evening
Well I found the seals and end caps at a Westerbeke dealer in St. Petersburg FL. The seals are flat, making the above question about elongated dimples kind of crazy, except that they exist. I'm going to guess that some sea water permeated the seals and became trapped between the seals and end caps and took a permanent set when hot.

The package the seal kits came in listed a 2 ft-lbs of torque for the bolt holding the end caps in place.
The new end caps are twice as thick as the old ones.

I look forward to scraping the scaling from the face ends of the HX, flushing with water, vacuuming the debris from the engine basin, and assembling the parts.

FYI, I found a new pet-cock at a Goodyear Rubber Products store. They had lots of brass fittings.

Mike Cronin
FlagShip, #314