Colt Case Ingersoll Garden Tractors

MattA wrote: ↑Sat Oct 11, 2025 8:34 pm Has anyone put together a list of parts required to test the relief valve settings for both travel and lift circuits?

MattA wrote: ↑Sat Oct 11, 2025 8:34 pm Has anyone put together a list of parts required to test the relief valve settings for both travel and lift circuits?

dhitching wrote: ↑Sun Oct 12, 2025 12:07 pm

MattA wrote: ↑Sat Oct 11, 2025 8:34 pm Has anyone put together a list of parts required to test the relief valve settings for both travel and lift circuits?

If you have a rear PTO it's pretty straightforward. Because the PTO is the first item on the hydraulic circuit right off the pump, you can put a gauge inline and see the pressure when you trigger the lift relief or the travel relief. You can also use a ball valve to test the PTO relief, closing the valve slowly until the relief valve on the PTO is squealing.

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Note that on any tractor with a dual pump setup this will only check items on the travel circuit. So on a 6018 or 4120 you can't check the steering or loader relief via the PTO.

MattA wrote: ↑Thu Oct 16, 2025 9:37 pm Does anyone know if the later 4 digit tractors with the backhoe transaxle had the standard 2100PSI relief or if they were increased to 2400PSI like the loaders.

dhitching wrote: ↑Fri Oct 17, 2025 8:19 am

MattA wrote: ↑Thu Oct 16, 2025 9:37 pm Does anyone know if the later 4 digit tractors with the backhoe transaxle had the standard 2100PSI relief or if they were increased to 2400PSI like the loaders.

The 4 digit backhoes followed the loaders from 2100 -> 2400 -> 2750 -> 3000 over the years. It should be noted that the later 4 digit backhoes got 3000psi rated Eaton pumps instead of the 2500psi rated Parker HD pumps the loaders and early 4 digit backhoes got.

MattA wrote: ↑Fri Oct 17, 2025 8:12 pm I should have specified 3000/4000 series. Good to know the backhoe history

MattA wrote: ↑Thu Oct 16, 2025 9:37 pm Does anyone know if the later 4 digit tractors with the backhoe transaxle had the standard 2100PSI relief or if they were increased to 2400PSI like the loaders.

MattA wrote: ↑Fri Oct 17, 2025 8:12 pm
I should have specified 3000/4000 series.

dhitching wrote: ↑Sat Oct 18, 2025 11:05 pm

MattA wrote: ↑Thu Oct 16, 2025 9:37 pm Does anyone know if the later 4 digit tractors with the backhoe transaxle had the standard 2100PSI relief or if they were increased to 2400PSI like the loaders.

MattA wrote: ↑Fri Oct 17, 2025 8:12 pm
I should have specified 3000/4000 series.

With a small sample size of two, I measured 1800psi on the travel circuit relief for both my 4221PS and my 4223PS/PTO. Assuming the spec is unchanged from the 2100psi spec on the earlier 4000 series tractors, they're both off by ~300psi. I also measured the relief in the PTO for both tractors (spec of 2200psi) with the 4221 measuring at 2000psi and the 4223 measuring at 1800psi, I bumped them both up to the spec value.

Reminds me why the 4100s are so much better at ground work with their 2750psi pressure relief!

Harry wrote: ↑Sun Oct 19, 2025 9:59 am I own a few Case GT’s and the 446 lift with snow caster on always squealed when lifting. So when I bring this GT into the shop before the white stuff comes, I’ll be adjusting the pressure relief for the lift control. Amazing to ne the 644 lbh has no pressure relief issues, especially on the D100. It just digs away effortlessly which is way cool. Harry

MattA wrote: ↑Sun Oct 19, 2025 9:16 pm Did the 3100/4100 series use a different drive motor? I know they used a larger pump (12gpm?)

MattA wrote: ↑Mon Oct 20, 2025 10:27 pm Thanks for going into the extra detail

Did the 4 digit loaders also use the same drive motor?

ssmewing wrote: ↑Tue Nov 11, 2025 4:26 pm I have a 648 that is after the original settings, and I suspect the pumps used. The visual tells are in the parts manual. I have a full hex nut on the cover for adjusting the TCV pressure.

I have mine all torn apart and have not been doing so well, and it has been sitting. I did buy an extra-long screw driver for the job, and I did have to drop the 3-point to access the hole fully. I hit the same issue as Harry? You cannot get to the nut. I have the add-on version of the retard that I cannot remember the name of. I did not want to be that guy who cuts holes for access after barating people who cut sections of their tower out instead of unbolting the engine and moving it forward for access. Then, recently, I found out that starting with the 6018, the factory created an access hole for adjusting the pressure relief. Now, I will cut an access hole. I will drill two holes, cut out the center, and then put a cover on it, similar to the 6018.

I, too, found I was at 1,500 psi. I followed the hydraulics manual and performed the bench test using the grease gun filled with oil method, turning it up to 2,400 psi, as per the setup I used, which required a much higher-rated check valve, but I was still able to see how far the needle would swing and never go past that, so the needle did not hold after each pump. I just had to pump faster.

It seems that way back when the other forum had Tom and Gator around, they both agreed that pump specs are arbitrary and meaningful. So, even though the pump says it is only as high as 3,000 rpm's was never a hard limit, but it was more a decision by the engineers using factors that we do not know.