3/8" ID Coolant Hose for M-25XP

Ward H

.
Nov 7, 2011
3,645
Catalina 30 Mk II Barnegat, NJ
My M25-XP has two short lengths of 3/8" hose running from the thermostat housing to brass adapters where it transitions to 5/8" hose.
Time to change out these hoses.
I checked with the usual sources and the only 3/8" marine hose I can find is fuel line and silicone heater hose. The silicone heater hose is not fuel/oil compatible.

Anyone know where I can find 3/8" hose suitable for this use?

Hose.jpg
 
Nov 12, 2009
238
J/ 32 NCYC, Western Lake Erie
Is there a problem using fuel/gas line to carry water or anti-freeze?
 
Nov 10, 2012
22
S2 9.2 ST IGNAGE, MI
I got the pre formed hose for a m25 from the local Kubota tractor dealer. They looked up the part using a b6200 tractor. I do not have the part # for you.
 

Ward H

.
Nov 7, 2011
3,645
Catalina 30 Mk II Barnegat, NJ
I looked at the hoses again. One is flexible and has a braided covering. That one is painted silver so may be original. The other does look to be a formed hose. It is painted copper so not original.
I never thought about visiting the auto parts stores so I'll do that over the next few days.

@Stu Jackson , I read your thread on the lower hose replacement when I was looking for a replacement for that one. On my M-25XP that formed hose is 1". There is a brass reduction elbow to reduce the 1" to 7/8".

Thanks for all the help, everyone.
 

Ward H

.
Nov 7, 2011
3,645
Catalina 30 Mk II Barnegat, NJ
Found a hose that will work at the local AutoZone. I had to look through their formed coolant hose rack to find it.
Dayco 87001 is a 3/8" ID Formed Coolant Hose about 14" long with a 90 Deg bend at one end. It will give me the 3/8" 90 Deg formed hose I need as well as the 3/8" straight hose.
IMG_1736.jpg
Hope someone else can use this info.
Hoping to finish up changing out all the engine cooling hoses this weekend.

Thanks
 
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capta

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Jun 4, 2009
4,766
Pearson 530 Admiralty Bay, Bequia SVG
Perhaps I'm seeing things wrong, and if I am I apologize, but it looks as though you have two hoses hose clamped inside another hose to go from one size to another. This is a sure fire recipe for disaster. I would replace whatever fitting wherever it is (sea strainer?) with the proper size nipple and run the correct size hose directly to the pump or at least use a reducing nipple at this point and get rid of the mickymouse connections in the picture.
 

Ward H

.
Nov 7, 2011
3,645
Catalina 30 Mk II Barnegat, NJ
@capta Yep, looks are deceiving.
After a little more research I discovered one nipple is on the T Stat and the other on the water pump. A single 3/8" hose connected them to become the T Stat by pass connection.

To supply hot coolant to the water heater Catalina inserted brass 5/8" to 3/8" reducers into the by pass hose to reduce the 5/8" heater hose to 3/8".

Heres a pic of the reducer.
IMG_1745.jpg