Hey guys, new to the forum so hey and hope you can help me on this one. We have on Cat in our fleet and it gives us the most trouble, but I think I was stitched up on the purchase. This one is a 330 bl and is overheating on the hydraulics after about 1.5hrs. Ambient temp is about 25 degrees celcius. Runs hyspin 68 oil, has a new oil cooler and engine temp is fine. Any ideas?
All the filters are clear? I know you have a new oil cooler how long ago did you replace that? what was the reason was it to try and fix this one?
How is the machine performing? Overheating hyd might be a leak or restriction some place. Check for a slow return checkvalve near the cooler, sometimes the insides back out and restrict return oil. Later Bob
Hey gents, cooler was replaced as it was rusted out, will change filters tomorrow and do an S.O.S and track cycle test for pumps. Cat were thinking about pumps straight away and I am hoping it will be something simple like a filter! Bob is the check valve in the tank return line after the cooler?
James, the slow return checkvalve is to hold a backpressure on the swing return and prevent the motor from cavitating. It should be on the LH end of the main control valve near the cooler. The inside can back out and restrict or prevent the valve from opening. Later Bob
Hey bob, is this a cat thing you speak of or a standard issue? Main valve bank should only have circuit reliefs for each control and a main relief. I am missing something here I think..... Are you talking about the swing motor return? These are all without circuit reliefs I believe but will check in the morning.
James, if memory serves me right the swing case drain line should go to it. It will hold a head of case pressure in the swing motor for the make up valves to get as the swing slows down when the main spool is closing and during soft swing. It should be an aluminium valve body beside the main valve and it may be common with the cooler bypass that could also be causing trouble but you have likely already looked at it. If the return valve backs out bad enough it will effect pump performance, backs up return oil and keeps NFC (negative flow control) pressure high and pumps stroked down. Look up cooler bypass valve in your parts book if you have one. Later Bob
Thanks bob you were spot on. The head of the valve had come off and jammed up against the cooler bypass. I think that's it for the heating issue. Will test in the morning as I was getting kicked out the door tonight as the site was shutting down. Will let you know. James
James, I made a socket to tighten them in, used a piece of steel pipe and cut slots in it. If it backs out again I would change the Oring, they tighten up easy but lock the plug in. Later Bob
Thanks bob will do. No more overheating now. Thanks again mate.
hey guys i have the same with my 330BL Rega (hyd oil overheating), i was thinking it could be the valve banks as we changed oil cooler,pressure washed it,changed the oil from 68 to something heavier like 130-150 and filters, but still overheating
I'd be going way lighter on hydraulic oil, not heavier. Standard oil spec is 32, I've seen machines running 46 quite often. 68 viscosity oil is usually only required in ambient temperatures of above 40DegC/100DegF. IMO using heavier than 68 in a Cat hydraulic system would be almost unheard of. Hydraulic oil viscosity may not be the root cause of your problem though but don't go too heavy thinking it will help, it may hinder. When you pressure washed the cooler did you remove it from the machine..? It's almost impossible to clean both the cooler and the radiator without separating the two. Have the simple things been checked like the fan drive, belts/tension, radiator ducting..?
we spoked to someone who had the same problem,they said the oil we were using was a bit light for that machine,we didnt remove the cooler when we washed it but after we washed it and it still didn't make a difference , so we jus changed out the cooler altogether ,NOTE:the engine runs perfect and it does not overheat the max temp is might reach is pass 3 bars on the display
Ow btw when the oil gets to about six bars on the panel it starts to slow down (machine) the swing especially gets slower and the boom raise and stick move slower, can some one help me please this is our only working machine at the moment.
Hey, my 330D excavator is also overheating hydraulic and engine. I checked bypass valve. The slow return check valve is little bit damaged on its extremities. Could that lead to the overheating problem?. Noting that the bypass valve is still good. And noting that at speed 10 the excavator when I raise the boom up and I keep the joystick on its postion the engine will go from 1950 rpm to 1550 rpm then go up to 1750 rpm. Power shift and negative flow are well calibrated. And at lower speeds performance isn't so good.
my name is nihar. i m mechenic last 11 years hydrolic experiance so bro cheq ur hydroulic returne filter & in side returne filter returne valve is not open no aal time so first service that valve after cheq hydroulic oil cooller fan speed if this not running on high speed after 60 c. so cheqe fan moter & thermostate valve
Am having a330bl with an engine. overheating and i have change the head gasket but still .
Hullo guys. I need your help. I have a cat 320L rega. The hydraulic is overheating after 2 hours of operation upto 7 bars and it lights the indicator warning. When it reaches 7 bars it loses power and at 6 bars it loads the engine. The engine temperature is normal. I pressure washed the cooler and radiator and changed filters but no difference.can u help?
Hi, Please refer the below mentioned thread and i think you can get some valuble tips from it.