Hydrostatic Drive System Sluggish After 15 Minutes of Use 630 Clark Skidsteer

[discountufoparts]

I have a late 70's Clark 630 skidsteer. It has been working great all along. I use it tops an hour a day. Then I had a ton of work to do with it for about 4 days using it about 8 hours a day. Now I have a sluggish response from the drives after I use it for about 15 minutes. Any ideas on this? This machine was burnt and I rebuilt it so I really have no gauges on it whatsoever or warning lights. The mast and boom rams all work fine but when I use them it increases the sluggishness of the drives even more. Am I experiencing a collapsing hose maybe or something of the sort. Is there any sort of filter in the hydraulic tank itself. It has a 28 HP Kubota Naturally Aspirated Diesel Engine that runs excellent so it is in no way engine issues. Thanks in advance for any advice you can give me.

 

[OldMachinist]

The first couple of things I'd check are the bronze filter in the port block and the oil cooler for debris blocking air flow causing the oil to overheat and thin out.

 

[discountufoparts]

The first couple of things I'd check are the bronze filter in the port block and the oil cooler for debris blocking air flow causing the oil to overheat and thin out.

Thanks I will check that filter. There was no oil cooler on my machine when I got it. Is this something I should definitely get and install?

 

[OldMachinist]

Thanks I will check that filter. There was no oil cooler on my machine when I got it. Is this something I should definitely get and install?

It would have had a oil cooler originally. There's a port on the port block that would have had the temp switch in it you could install a sending unit and gauge to see what the oil temp is running.

 

[Fabricator]

It would have had a oil cooler originally. There's a port on the port block that would have had the temp switch in it you could install a sending unit and gauge to see what the oil temp is running.

I did the bronze screen replacement the other year for similar symptoms. I'd definitely get a sending unit and cooler on the system. What you're describing is likely overheating the hydraulic oil.

 

[mrdeere1959]

I did the bronze screen replacement the other year for similar symptoms. I'd definitely get a sending unit and cooler on the system. What you're describing is likely overheating the hydraulic oil.

$ 173.55 for a new cooler

 

[discountufoparts]

$ 173.55 for a new cooler

Just got around to draining the hydraulic which is 10W30 oil. Looks and smells terribly burnt. Got a couple of new filters, one to use and one to spare. I will take the seat and everything off tomorrow to get to the bronze filter.

 

[Tazza]

Just got around to draining the hydraulic which is 10W30 oil. Looks and smells terribly burnt. Got a couple of new filters, one to use and one to spare. I will take the seat and everything off tomorrow to get to the bronze filter.

No wonder it smells burnt, make sure you get one installed. If the pumps get too hot they will be damaged.

 

[discountufoparts]

No wonder it smells burnt, make sure you get one installed. If the pumps get too hot they will be damaged.

So I went to the spot to take out that filter and spring and when i took the fitting off there is nothing but a big empty space there. I take it this is an important filter and if so where can I order the spring and filter? Thanks