Merlo P25.6 oil cooler problems

[KnotsDown'nOut]

Hi this forum seems to carry the foremost experts on Merlo teleporters outside of Merlo themselves based on my research!

Old merlo P25.6, oil cooler burst, repaired, burst again, tried another second-hand cooler which burst also. As this is an old machine it could be end-of-life issues for the coolers concerned but before going further I would like to understand the hydraulic circuitry and pressures concerned to see if there is anything else going on.

I have sketched the hydraulic circuit around the oil cooler attached as I see it. Oil supplied from charge pump under block valve goes through the same block valve, vertically upwards to oil cooler (this line pressure measured at 250 psi), from oil cooler to filter, then seemingly back to the same block valve again - this is the bit I do not understand.

If anyone could shed light on how this is supposed to work much obliged. Is the block valve just a distributor or is it doing something more such as regulating the oil pressure to the oil cooler?
Be in touch.

 

[Planttech]

Hi this forum seems to carry the foremost experts on Merlo teleporters outside of Merlo themselves based on my research!

Old merlo P25.6, oil cooler burst, repaired, burst again, tried another second-hand cooler which burst also. As this is an old machine it could be end-of-life issues for the coolers concerned but before going further I would like to understand the hydraulic circuitry and pressures concerned to see if there is anything else going on.

I have sketched the hydraulic circuit around the oil cooler attached as I see it. Oil supplied from charge pump under block valve goes through the same block valve, vertically upwards to oil cooler (this line pressure measured at 250 psi), from oil cooler to filter, then seemingly back to the same block valve again - this is the bit I do not understand.

If anyone could shed light on how this is supposed to work much obliged. Is the block valve just a distributor or is it doing something more such as regulating the oil pressure to the oil cooler?
Be in touch.

Charge pressure should be around 24bar so 350psi. On a machine I have here one hose is tee’d into the fitting on bottom of header tank hose and the other on the ally block on top of pump

 

[Planttech]

Also it that original engine or someone fitted slightly different one?

 

[ACEngineering]

Charge pressure should be around 24bar so 350psi. On a machine I have here one hose is tee’d into the fitting on bottom of header tank hose and the other on the ally block on top of pump

Seems awfully high pressure for an oil cooler