I was wondering if anyone could identify the purpose of the two coolant lines (pictured) going to/from the injector pump on this Yanmar 3TNV88 engine (the 4 cylinder one has the same). My friend has a Takeuchi TB138FR digger which is fitted with such an engine. He has recently had the water pump replaced after just 1500hrs and the cost of the new water pump from Takeuchi is nothing short of extortion especially since the machine is just over 2 years old. So we’ve been looking into sourcing a spare water pump via other means. We can buy a genuine Yanmar pump for less than half the Takeuchi price or a non-genuine one for about a quarter of the price. However the aftermarket pumps don’t appear to have the extra two spigots for those hoses leading to the injector pump. We could probably install them but I was curious as to the purpose of sending coolant to the injector pump as it may not be required in a warm climate like Australia. Thanks for any help. Chris Brisbane Australia. (and yes, we’ve seen the chafed hose – that’s from the coolant overflow bottle.)
Hi Chris, Coolant lines to injector pump ???? Your absolutely sure they are coolant & not fuel return?
Hi Alrman. Yes, definitely coolant in and out of that banjo. The hoses lead to small fittings on the water pump/thermostat housing. I’m guessing it’s for cold starting or temperature compensation or something. I was just wondering if it was only for sub-zero temperatures, maybe we could do without it here. The injector pump is a Yanmar YPD-3MP2 model. Chris.
I found it indeed has coolant going to it! It has a "thermo element" in it which will control engine timing when coolant is either hot or cold - so I think it would have to stay attatched. You could talk to a diesel injection pump room to confirm this - it may be possible to lock the timing in place somehow - it all has to do with emmissions. here's a link to a service manual for the pump http://ce.hhi.co.kr/eng/parts/sm/ENGINE/9.pdf If the water pump is fixed - you might not need to worry about it again ???
Excellent, thanks for your trouble Alrman. I agree the coolant lines will have to stay else we’ll have no idea what it’s doing as that “thermo element” will just register warm (not hot or cold) if the coolant isn’t flowing through. The owner is concerned that if the pump only lasts 1500 hours he’ll be doing it again in the not-too-distant future and it cost him $2000 (including labour) this time around. So we’ve been looking at alternatives. I think even with an aftermarket pump that’s missing the two coolant tubes, we could drill it and install the tubes as they are just pressed in. Thanks again. Chris Brisbane Australia.
$2000 !!! - I would have done it for $1900 :naughty I've never had a good feeling about that Tak dealer - can't imagine how that much money could be charged for fitting a water pump, even if it took all day to do ????
how much of the 2k was the pump? I have a tak 53, same motor, or same series of motors I believe.
Yes, I’m pretty sure the 53 would have the 4TNV88 engine (exactly the same except one more cylinder). In fact the original water pump off the 3 cylinder has a part number showing it’s for the 4TNV88. The pump alone was invoiced at AU$1100 including our GST tax. The rest was labour and a handful of small parts (including a new thermostat). I don’t know how many hours were involved but even though it looks impossible, I know they didn’t remove the counterweight or anything like that. Stump, if you ever need to replace your water pump, I’d be getting a price off Takeuchi and then getting a price off a Yanmar dealer. Our prices (from an overseas source) were: Genuine Yanmar pump – AU$588 inc shipping Non-genuine pump – AU$305 inc shipping Our Aussie dollar is about the same as your dollar. My mate has a bad habit of getting work done on the machine without getting a quote or estimate first. That has now changed. He’s also written to Takeuchi USA about this but they generally don’t respond to complaints. And I agree about the dealer, Alrman. Nuff said.