Re: heat exchanger, belts , and oil cooler

seafeverofcuan <seafeverofcuan@...>

Hi Gary,
I took the gentleman's way out on this one and used my cheque book, this time I didn't physically do the work but I was there for all of it. A Yanmar trained technician took off both end caps, he also removed the turbo, oil cooler and the exhaust elbow as I was having a major service, including turbo recon,injectors, etc. @ 3000 hours.
I mentioned to him that I had tried to remove the heat exchanger last year and it didn't seem to want to move and I was reluctant to use force, so I flushed it with Barnacle Buster which lead on to seizing the gearbox when the transmission cooler failed. He simply tapped sharply a couple of times using a wooden circular plug from my emergency kit about 55mm in diameter, on the end from aft to forward and it moved, then he pulled it from the forward side and passed it up to me, easy as that. He told me that they are prone to sticking.
I helped put it back in and it simply slid into the casing and sealed on two O rings but they need to be new, then the end caps. He wouldn't tell me what they had used to clean it but it looked like brand new.
The Yanmar workshop manual shows how it draws out but offers no instruction.
For the previous six months or so I had been using a little bit of oil on long runs and this turned out to be yet another hole, this time in the engine oil cooler and it had to be replaced.
As normal, the diesel lab commented that I hadn't been running the engine hard enough, usually 2250 RPM. The correct revs for that engine are 2450 to 2650 RPM and there is no doubt since the service it has been running better than ever, although those extra revs increase the fuel usage to around seven litres per hour.
I hope this is of some help.

--- In amelyachtowners@..., amelliahona <no_reply@...> wrote:

Hi Trevor:

I just want to make sure I understand this, DETAILS ARE IMPORTANT:
1. We are talking about the Yanmar seawater/freshwater coolant heat exchanger that sits atop the engine, correct?
2. To drive the core that includes the heat exchanger tubes out of the engine housing, you used a wooden drift (presumably something fitted to roughly the size of the core, or about 5 x 5 cm), correct?
3. What direction did you drive the core out, from aft to forward or the other way around?
4. Can you please confirm that the only thing holding the core in the engine housing is the o-ring on each end of the core?
5. How much hammering on the core did you have to do? Did risk bending the tubes or damaging the core?

Thanks for clarifications.

Gary Silver
s/v Liahona Hull # 335

--- In amelyachtowners@..., "seafeverofcuan" <seafeverofcuan@> wrote:

Hi Eric,
The Yanmar cooler will come out if you use a wooden drift like the thick side of a wedge and tap it gently with a mallet, but don't do it unless you have NEW gaskets as it won't reseal.
As far as the tranny cooler goes, it would be better to use new end caps, you need thinner jubilee clips than normal to get a good bite on the sea water pipe which has a nylon sleeves inside it and there isn't much room to get a good purchase .
The new cooler I fitted in May came with caps and clips.
From my own bitter experience I would ask a radiator shop about a cleaning agent that would be gentle rather than proprietary products like Barnacle Buster or On Offn
Best regards,

Sea Fever
--- In amelyachtowners@..., "Judy and Bill aboard SV BeBe" <yahoogroups@> wrote:


I have reviewed my notes and cannot find the photos I know I made when I did this in 2008. I do not remember any seemed straight forward at the time...possibly the tube assembly does not come out of the housing.

Regarding the exchanger gaskets check this out:

I did not have these gaskets and had to cut them from gasket was very difficult as the gasket is extremely intricate. Part number 129693-44420 was the part that I ordered and now have as spares since I cut gaskets at the time. Regarding the O ring 24321-001000, I found these these at Yanmar Panama, but probably did not need to replace them...the old ones looked good...unlike the gaskets which tore apart on removal of the end caps.

Sorry that I am not much help.

BeBe, SM2k, #387
At the Amel Pontoon, Gocek, Turkey

--- In amelyachtowners@..., "Judy and Bill aboard SV BeBe" <yahoogroups@> wrote:


It may be 24 hours before I can reply. I am off the boat now and need to return to answer your questions.


--- In amelyachtowners@..., kimberlite <kimberlite@> wrote:


How did you get the heat exchanger out? I removed the end caps and could
not get the exchanger to slide out of its housing. I also do not see the
part number Gasket - Heat Exchanger 129693-44420 2- each listed in my

Also the belts are standard dayco belts number 17475 or 13a1205 they come
in matched sets. Same belt as the yanmar belt but better construction.

They have grooves cut into the top of the belt and allows the belt to have
more flexibility. My first set I had to get from Europe as the number was
13a1200 meaning 1200 long the USA replacement is 1205 mm long .

they are available in most auto parts stores. I got this info from the
dayco engineers, the 1200 mm version is only available for export.

I also thought that I was pushing my luck with the tranny oil cooler after
10 years .In Europe it is 500+ euros. Here it was $137-

Here is a note from the USA Rep of the British manufacturer. The Unit is the
DC60 . Made by bowman. You must order the 3367 end caps or use the old ones.

From: Sales & Engineering [mailto:sales@]
Sent: Thursday, April 11, 2013 8:39 AM
To: 'Sailorman'
Subject: RE: Marine transmission oil cooler


Thank you for the inquiry. The unit that you have there appears to be one
of the DC Series coolers; I think it is the DC60. We do not have that unit
in stock but have he next size up, I'm not sure if you have the room to go
with a longer cooler or not. Following is the pricing for both units,
please let me know if you have any questions or need further information.

Model #DC90-XAA

Price $153.60

*Unit has 3/8" BSPP oil connections and 22mm I.D. x 32mm O.D. straight hose

Delivery - In stock and can ship same day from our Watertown, MA location.


Price $137.00

*Pricing is good for any configuration.

Delivery - Allow 4 to 6 weeks

See attached catalog for dimensional data and connection sizes and

Best Regards,

Bob Bangs

Sales Representative

Therma-Flow, Inc.

Phone: 1-617-924-3877

Fair Winds


Kimberlite Super Maramu #376


From: amelyachtowners@...
[mailto:amelyachtowners@...] On Behalf Of Judy and Bill aboard
Sent: Wednesday, June 12, 2013 5:28 PM
To: amelyachtowners@...
Subject: [Amel] Re: How to acid clean sea water intercoolers


Before removing and cleaning the heat exchanger on the Yanmar 100hp, order
these parts:
Gasket - Heat Exchanger 129693-44420 2 each
O Ring - Heat Exchanger 24321-001000 2 each

You may not need to replace the O rings, but the gaskets are very delicate
and will tear when the exchanger is disassembled.

I drained the coolant before starting and reused the same coolant. I also
used this opportunity to change the thermostat, gasket and the 3 fan belts.
Thermostat 129470-49801 1 each
Gasket, Therm 129795-49551 1 each
V-Belt 25132-004600 3 each

Disassembly/assembly is straight forward. It has been several years ago and
I do not recall any issues or problems.

Hope this helps.

BeBe, SM2k, #387

--- In amelyachtowners@...
<> , "Judy and Bill aboard SV BeBe"
<yahoogroups@> wrote:

Gary, I will completely answer when I can get to my laptop. It was the
freshwater exchanger. There are some gaskets and O rings you must have
before attempting. I will come back with details and part numbers.



--- In amelyachtowners@...
<> , amelliahona <no_reply@> wrote:


That is very helpful. Thanks for the On-Off info. I will look into it.
When used as a hull cleaner does it etch the gelcoat at all?

Which Yanmar heat heat exchanger did you clean? Was it the fresh water
to sea water exchanger, the seawater to engine oil exchanger, or the sea
water to transmission fluid exchanger?

I know that the Yanmar sear water to fresh water heat exchanger tubular
core is a separate part from the housing in which it sits. Can you elaborate
on the removal process/difficulty if indeed you have done that?

Thanks for all your help.


--- In amelyachtowners@...
<> , "Judy and Bill aboard SV BeBe"
<yahoogroups@> wrote:


I was in New Zealand and could not buy acid because it requires a
special license...I had a marine engineering shop do it for me.

However, I did acid-wash the heat exchanger core on the Yanmar using
On-Off which is a combo of hydrochloric, oxalic and phosphoric acids. I let
the heat exchanger core soak in the On-Off for about 5-10 minutes until it
was visibly clean. I then rinsed it with fresh water and soaked it in a
bucket of baking soda and water to neutralize any residual acid.

A side note about On-Off: On-Off is advertised as a hull cleaner, but
is also an excellent metal cleaner and rust remover. DO NOT USE it on chrome
plated turnbuckles or chrome plated winches as it will remove the chrome.

Hope this helps.

BeBe SM2k, #387

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