Hydraulic oil temp older Kobelco sk300 Mk 4

[Dave Varabioff]

Have a question about the hydraulic system on my Kobelco Sk300 LC Mk4. Want to make sure I am not gonna fry my hydraulics. Over 6k hours. Pump was an aftermarket 400 hours ago and runs great. Here is my operators concerns. We measure the pipe temperature at the bottom of the Hydraulic pump and its 185 (but really ALL steel components on that side including bell housing, door etc are that hot, that radiator fan pulls the air in that direction so kinda makes sense to me). On the radiator side the intake side pipe is 170 degrees, the discharge pipe (coming out of the cooler) is about 130 degrees and the side of the hydraulic oil tank is about 170 as well.

Am I doing damage at those temps?

dave

 

[TVA]

Its not that simple! First what aftermarket pumps is in that machine? Is it clone of K3Vs, original K3Vs rebuild with aftermarket parts, or something totally different?!
We need to know what that pipe to the bottom is doing? Is it pump suction pipe, or the pressure discharge hoses?

Most important temperature you need to measure is pumps them selves and discharge hoses!
Ideally 160F ( if ambient permits ), 195F or over its a danger zone! Over 206F you killing it!

 

[Dave Varabioff]

Ran with side door open and the steel parts still get to about 185, but piping into and out of oil cooler are consistent at 164 and 142. I think I am ok......
dave

 

[Dave Varabioff]

Its not that simple! First what aftermarket pumps is in that machine? Is it clone of K3Vs, original K3Vs rebuild with aftermarket parts, or something totally different?!
We need to know what that pipe to the bottom is doing? Is it pump suction pipe, or the pressure discharge hoses?

Most important temperature you need to measure is pumps them selves and discharge hoses!
Ideally 160F ( if ambient permits ), 195F or over its a danger zone! Over 206F you killing it!

It was a clone of K3V out of China from Summex parts. The bottom pipe is 185 degrees at its hottest but ALL components on that side (well anything steel) is same temp and bell housing is actually 202 deg. Pipe into oil cooler is 164, pipe out is 142. Air temp is 90 (ambient)

Dave

 

[TVA]

Is the heat shield between your engine and pump bays and hydraulic tank intact?! If by bottom pipe you mean suction pipe then it is picking up temperature in the tank, and that might indicate excessive bypass to case drain!

 

[TVA]

I’m not familiar with 300, Are those pumps tandem or parallel?

 

[Dave Varabioff]

Is the heat shield between your engine and pump bays and hydraulic tank intact?! If by bottom pipe you mean suction pipe then it is picking up temperature in the tank, and that might indicate excessive bypass to case drain!

There is NO shield between engine and pump bay, its a wide open space and all air drawn from fan goes right through (been that way for 2 years since I bought it).

I don't know enough about excessive bypass, I'm just an idjut gold miner. And yes by bottom pipe I mean the 4" pipe going from tank to bottom of hydraulic pump. I haven't changed the suction screen since I've had this thing so am gonna do that this week as well.

I appreciate you answering my questions, gives me at least somethings to look at.

I do have the shop manual so will look at bypass and see which pipes those are

dave

 

[TVA]

I asked about heat shield between engine/pump bay and hydraulic tank, are those pumps piggy back or side by side?

 

[Dave Varabioff]

I’m not familiar with 300, Are those pumps tandem or parallel?

its this one K3V180DT

 

[TVA]

Bypass means no good! You not gonna find it in manual! It means that your pumps is leaking through valve plates, or pistons back to tank through case drain!
Measure the temperature of pumps themselves and two pipes that connect pumps to main control valve.
Also the smaller hose that goes from the side or top of the pumps back to tank.

 

[TVA]

its this one K3V180DT

That’s a tandem, your bellhousing high temp is probably the heat from the engine and not problems with gear drive!

 

[Dave Varabioff]

I asked about heat shield between engine/pump bay and hydraulic tank, are those pumps piggy back or side by side?

No heat shield at all, wide open from engine to pump.

dave

 

[TVA]

If 4 inch pipe comes to the bottom then pumps laying on the side

its this one K3V180DT

Wait a minute! 180?! I don’t remember Kawasaki making 180 displacement in K3V not K5V! Chinese came up with their own displacement

No heat shield at all, wide open from engine to pump.

dave

OK, how about between pump bay and hydraulic tank?

 

[Dave Varabioff]

Bypass means no good! You not gonna find it in manual! It means that your pumps is leaking through valve plates, or pistons back to tank through case drain!
Measure the temperature of pumps themselves and two pipes that connect pumps to main control valve.
Also the smaller hose that goes from the side or top of the pumps back to tank.

All the pipes you mention are 185 degrees when running full on

dave

 

[Dave Varabioff]

If 4 inch pipe comes to the bottom then pumps laying on the side

Wait a minute! 180?! I don’t remember Kawasaki making 180 displacement in K3V not K5V! Chinese came up with their own displacement

OK, how about between pump bay and hydraulic tank?

The 180 I mention is degrees farenheit (not displacement). No heat shield between pump bay and tank either, just airflow from motor passing through the bay and the left wall of the tank is the right side of the pump bay.

dave

 

[TVA]

Whatch it! If you will start having seals and O-rings failures you will know why!

 

[TVA]

I was wrong about 180 displacement, Kawasaki don’t offer that now new!

 

[Kobelco ireland]

TVA asked a good question about the heat shield panels. Your machine should have them if not you end up with heat transfer in pump compartment from engine, turbo, exhaust etc. These should be replaced, if not replaced its hard to get correct temperature readings and all that heat will damaged pipes, o rings, wiring etc etc. Also was hydraulic oil changed when new pump were installed or when was hydraulic oil last changed

 

[Dave Varabioff]

TVA asked a good question about the heat shield panels. Your machine should have them if not you end up with heat transfer in pump compartment from engine, turbo, exhaust etc. These should be replaced, if not replaced its hard to get correct temperature readings and all that heat will damaged pipes, o rings, wiring etc etc. Also was hydraulic oil changed when new pump were installed or when was hydraulic oil last changed

Been a while since hydraulic oil changed and there are NO heat shields, I don't even see place to mount one so Im going to fabricate a barrier and insulate it. I tried to find picture online of this machines engine compartment and couldn't. The service manual doesn't list a heat shield either.......but it makes sense to have one as all that heat does affect the pump and the left wall of the hydraulic tank

Dave

 

[Kobelco ireland]

On original panel there is no insulation just steel panels. I will try find picture of one for you