Which engine is used in the Yanmar YB20 excavator?

   / Which engine is used in the Yanmar YB20 excavator? #1  

Jaap

New member
Joined
Jan 10, 2025
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15
Tractor
Yanmar YB20
Since 1999 I own an pretty old (but extremely reliable) former Yanmar YB20 mini-excavator that had been transformed into a forklift with tracks, before I bought it. So I have only used it as an "all terrain" forklift on tracks. Has never let me down. Until yesterday, when I heard a knocking sound coming somewhere from the engine bay. Turned out to be the waterpump. I can move the fan pulley freely back and forth 5 or 6 millimeter. So I am looking for a replacement waterpump, but I can't find the engine code / engine serial number. Does anybody know which engines are used in the YB20?
 

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   / Which engine is used in the Yanmar YB20 excavator? #2  
Since 1999 I own an pretty old (but extremely reliable) former Yanmar YB20 mini-excavator that had been transformed into a forklift with tracks, before I bought it. So I have only used it as an "all terrain" forklift on tracks. Has never let me down. Until yesterday, when I heard a knocking sound coming somewhere from the engine bay. Turned out to be the waterpump. I can move the fan pulley freely back and forth 5 or 6 millimeter. So I am looking for a replacement waterpump, but I can't find the engine code / engine serial number. Does anybody know which engines are used in the YB20?
1736545740485.png
 
   / Which engine is used in the Yanmar YB20 excavator? #3  

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   / Which engine is used in the Yanmar YB20 excavator? #4  
Since 1999 I own a pretty old (but extremely reliable) former Yanmar YB20 mini-excavator that had been transformed into a forklift with tracks, before I bought it. So I have only used it as an "all terrain" forklift on tracks. Has never let me down. Until yesterday, when I heard a knocking sound coming somewhere from the engine bay. Turned out to be the waterpump. I can move the fan pulley freely back and forth 5 or 6 millimeter. So I am looking for a replacement waterpump, but I can't find the engine code / engine serial number. Does anybody know which engines are used in the YB20?
Welcome to TBN!

That sounds like an interesting machine. Can you share some photos? What do you use it for?

All the best,

Peter
 
   / Which engine is used in the Yanmar YB20 excavator? #5  
Welcome to TBN!

That sounds like an interesting machine. Can you share some photos? What do you use it for?

All the best,

Peter
It may come in one of 3 colors. Yanmar yellow is the most common.
1736555874631.jpeg


It's sibling is the Komatsu PC20 or one of the PCxx machines...
1736555987932.jpeg
 
   / Which engine is used in the Yanmar YB20 excavator? #6  
   / Which engine is used in the Yanmar YB20 excavator?
  • Thread Starter
#7  
Wow, thanks everybody for the replies. Yesterday evening, very late, I found an old German instruction manual for the YB20 with a scheme of the hydraulic system. In the center of the scheme I saw a code 3T75H-LTBS which sounded like an engine code to me. And Bingo!! This seemed to be it. And now that I just reconnected to this forum, after waking up in the morning, I found the replies here, confirming this engine code and also links to waterpump. You guys are great. I'll try to share some pictures of my monster forklift. It has had a very rough life, already before I bought it 25 years ago, but like I said, it has NEVER let me down, not even once. These pictures are 23 years old, by the way. But the YB20 is still going strong, well okay, apart from the waterpump.
In 1995 I bought a former cattle farm and transformed it into a horse boarding stable. We decided to make fences of thermo galvanized scaffolding pipes, and over the years we had lots of work to do in the fields. I stumbled across this "tracked forklift" and it was exactly what we needed at the time. We also use it as a "normal forklift", I mean on paved surface, when necessary. We will remove the waterpump today, compare it with the 3T75H-LTBS water pump (of which I have found exploded views drawings on Yanmar's own site) and compare it with the replacements that are being sold online. Then I will order a replacement and we will install it at soon as it arrives because nowadays we use the YB20 on a daily basis to shovel horse manure on a stack with a large snow plough we fitted over the forks. I'll post some more pictures later on. Cheers!
 

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   / Which engine is used in the Yanmar YB20 excavator? #8  
Wow, thanks everybody for the replies. Yesterday evening, very late, I found an old German instruction manual for the YB20 with a scheme of the hydraulic system. In the center of the scheme I saw a code 3T75H-LTBS which sounded like an engine code to me. And Bingo!! This seemed to be it. And now that I just reconnected to this forum, after waking up in the morning, I found the replies here, confirming this engine code and also links to waterpump. You guys are great. I'll try to share some pictures of my monster forklift. It has had a very rough life, already before I bought it 25 years ago, but like I said, it has NEVER let me down, not even once. These pictures are 23 years old, by the way. But the YB20 is still going strong, well okay, apart from the waterpump.
In 1995 I bought a former cattle farm and transformed it into a horse boarding stable. We decided to make fences of thermo galvanized scaffolding pipes, and over the years we had lots of work to do in the fields. I stumbled across this "tracked forklift" and it was exactly what we needed at the time. We also use it as a "normal forklift", I mean on paved surface, when necessary. We will remove the waterpump today, compare it with the 3T75H-LTBS water pump (of which I have found exploded views drawings on Yanmar's own site) and compare it with the replacements that are being sold online. Then I will order a replacement and we will install it at soon as it arrives because nowadays we use the YB20 on a daily basis to shovel horse manure on a stack with a large snow plough we fitted over the forks. I'll post some more pictures later on. Cheers!
Jaap,
Glad to help.
Is the German manual for the YB20 in PDF to share?

Yes, I would like to see how the plow fits on the forks too.
 
   / Which engine is used in the Yanmar YB20 excavator? #9  
Great photos and thanks for sharing them.

We have a non-tracked tractor / front loader with quick change front attachments that we find incredibly useful. Our two most used attachments are probably the forks (to move hay), and the bucket (to move the manure from the horses eating the hay).
IMG_5151.jpeg


All the best,

Peter
 
   / Which engine is used in the Yanmar YB20 excavator? #10  
The lift height is what I noticed. Pic.4 my guess is the forks are around 10' then another 8' lift section. That could come in real handy also. Esp. with a pallet type deck to work on.
 

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