Hi all thanks in advance for information. Looking for case mechanics. I have a case 1450 not b. It struggles for enough power to push or turn even on level ground. It does move forward and reverse but will not power turn or pivot. High range doesn’t work. Low range works in hi/low track. Changed filters and fluid. Have 275 psi at control valve inlet. Screen at the test port was clear and it showed 15psi all the time no change when in neutral. I pulled the modulator and added too many shims it went to 50 back down to 35psi now. But it doesn’t change from that no matter the position of control levers. Among other tests, I’ve checked pressure to hi/lo range at the back of trans and get modulator pressure at both. So I’m thinking that the modulator is bypassing all the time? I can’t find anywhere what the pressure is supposed to be at the lines going to clutches. I don’t think that the brakes are holding it down cause I was able to pull it in neutral running. When it won’t push like a power turn or pivot the drive shaft still turns doesn’t seem to slow. Any ideas on what I should look at, what to test, what’s wrong? Also let me now if I’ve posted this in the wrong place. Be gentle this is my first time.
Watch your driveshaft from the seat. When in neutral it will be spinning. When you select forward or reverse it should stop the driveshaft until you start moving. If the machine quits moving but the driveshaft is still turning, then you have either lost a clutch pack or you have too low a pressure to keep the clutch engaged.
The drive shaft spins the same speed. How much pressure is needed to engage clutches completely?
Could you give us some more background information on this? Was the machine operating well, then suddenly failed? Over days or weeks got worse? Trans pressure gauge on dash working? Is it reading same as what you tested at valve? Brake pedals feel normal? Pressure spec is 250 - 310psi @ 2000rpm. So 275 you have should be ok. It may have a problem in the valve causing it to lose pressure - blown gasket or broken spring.
Sorry I don’t have much background myself. I bought it cheap from a guy that acquired it with a ranch purchase, he has new equipment and seen it for what it is. When I went to look at it the park brake was seized half applied and springs on the pedals were broke ,pedals sagging, and caked dirt around all filters. So I figured change filters fluid fix the obvious stuff and I’d have a good enough price of equipment to fix and maintain a steep rock driveway of mine. None of the gauges on the dash work. I am not sure what normal would be on the pedals, my first dozer. But I did verify that the rods in the control valve are in the right position, and not half way. I figure it’s loosing pressure but where would be the question. I have source pressure at the inlet to the control valve, 275. 30, at the test port. And 30 at the hi/lo range. I would think by looking at the flow charts I should have source at the hi/lo. That’s what I wanted to verify with you guys. Now, I found this afternoon that the retard valve was turned in flush to the cup that it sits in with very little flow, mouth air pressure. I’ll need to find my square drive sockets to pull the thermal valve out and check for damage/flow. My thought is that there isn’t enough pressure on the back side of the modulator to keep it in place. Kind of like riding your foot on the pedal. I may be in the wrong area here. Honestly I’m just pulling this thing apart and checking in the manual to see if anything is missing or broken one part at a time till I figure out how it works. If I get to move good then I can move to stopping. And making the dash work. I do have a service manual and the gauges I pieced together with a couple of 400psi gauges and hoses and misc fittings. Any insight on how to set the retard valve without the tool would be helpful too. I’d hate to just go with the “oh that felt harsh let’s back that off” method.
Wow that’s a long ramble for five answers.
Update. I adjusted the retard valve out to give more flow. Reinstalled. Ran it I now have 275psi at the clutch packs. Hi range now works and I was able to counter turn back and forth and power turn. I didn’t run it much maybe 20ft but huge improvement. I’m now going to work on other adjustments, detents modulator pressure and retard fine tuning. then get the brakes working right. thank you for your help. I could still use some insight on how the retard timing tester works and how to do it manually. Any questions from anyone else on this subject are welcomed I’ve learned alittle and willing to give what I know.
Hi Toby. I have one here that has the same problem as you had. I have a service manual but I don't see any reference to a retard valve. I added a shim in the pressure regulating valve in the torque convertor and it had 300 psi at the trans filter outlet and the dash guage was at the top of the yellow zone, after running it at 2000 ROM for a few minutes the main pressure dropped to 285- 290 and the dash guage dropped into the red zone. All the instructions in the manual explain how to diagnose with a flowmeter and the special valves for that testing, all I have is pressure guages and on IHC equipment I could always sort things out. Any addition info would be greatly appreciated. Thanks, Rocko59
I might be speaking out of turn here, but hopefully you don't have trashed clutches from it being operated at low pressures. I don't think the clutch linings are very forgiving.
Hi Shimmy. Thanks for jumping in, any help is good! I am wondering about that too, finding out how to check some pressures would be great. The markings on top of the trans valve don't make much sense. It does lose pressure as it warms up but it maintains decent pressure at the trans filter outlet.
I'm having the same issue it moves forward and reverse but won't turn good at all where is this adjustment at?