JD 450 H-L-R trouble

[dbrown148]

I have a JD450 with a H-L-R problem like was mention in one of the threads.
Here"s the history. When I bought the dozer in February it hesitated when you first started it up. After you first moved or bumped it with another piece of equipment it worked fine from then on until you stopped it and shut it off. It would push like crazy with no issues. I had my mechanic check it out and he found the dump valve on the clutch had a broken spring and the spring had worked into itself. He also replaced o-rings on the manifold. When he got it back together it moves fine every time on start up. We took it to a job and it didn't seem to push like it did before so I put the pressure gage on it and found only 80 psi hot. So we shimmed it to get 140 cold. Now after a few hours running it becomes sluggish and doesn't push well. Do I need to check the pressure again hot? Would Lucus help the situation? If it had done this all along I would think the clutch pack or pump was bad.

[LeonardL]

It would be my guess that you will have to go back through your adjustments for the HLR. I always tried to set things "Hot" as this is where the machine is going to be when running it. I wouldn't add any Lucas to it. Lucas is good stuff but it shouldn't be used as a cure all. Your HLR is designed to run and operate on a specific fluid viscosity and thickening it may cause you other issues.

[dbrown148]

Thanks. I'm going to run it a while tomorrow and heat it up. then check the pressure and go from there.

[dbrown148]

Well I ran it yesterday for about two hours before the problem showed up again. I called a mechanic buddy of mine and he told me to try a different type hydraulic fluid. I had Dutch Gold in it. I did as he suggested and it help tremendously. He said he had on older backhoe that would not hardly work using the cheaper fluid when it became hot. The only thing is it hesitates after shutting the motor off. Like its losing its prime. You can throttle it up pretty high and it will take right off. I'm thinking I may need to replace the H-L-R pump. Does anyone know where the best place to buy one or if they even make an aftermarket one?