CK25 HST push power problems…

[BigDogues]

Hi all, wow it’s been years since I’ve been here. I’m having issues with my CK25 hst. I have no pushing power in low gear as I try to feather it on the pedal. It will just blow past or if I manage to keep it engaged it will bog the engine at three quarter pedal. There is just no “oomph” in the bottom end. Scooping sand is difficult because to get a bucket load I practically have to ram the pile to load the bucket. Bucket lift power seems to be good though.
Since it has been so long I’m hoping someone had the same issue and can help me solve it.
Thanks,
Phil

 

[Robin Veerman]

Two things….are you in 4-wheel drive and is the rpms around 2000-2200? Should be both if you’re not. Also a pile of sand can become hard like concrete. Unless you’re in the Sahara desert where the sand is dry and loose. Ramming your tractor into a hard sand pile, you’re going to break something. Let me know…

 

[oldnslo]

Can you feather the travel speed when not under load or is it jerky all or nothing all the time? Does it respond differently in high range?

 

[BigDogues]

Two things….are you in 4-wheel drive and is the rpms around 2000-2200? Should be both if you’re not. Also a pile of sand can become hard like concrete. Unless you’re in the Sahara desert where the sand is dry and loose. Ramming your tractor into a hard sand pile, you’re going to break something. Let me know…

Doesn’t matter if I’m in two or four wheel drive. RPMs are up to the red indicator (2600,I think?) And the FEL seems to be strong. I can lift enough to raise the back tires off the ground. Although with a large counter weight on the back I’m not so sure.
It has had a problem with low end push for a long time. Sand, gravel, it doesn’t matter. It just seems like it should be spinning wheels as I feather the pedal. That never happens. It just groans until what I think it the relief popping off.
I plan on buying a pressure gauge to see if the pressure is where it should be.
BTW, it is not low on fluid.

 

[BigDogues]

Can you feather the travel speed when not under load or is it jerky all or nothing all the time? Does it respond differently in high range?

It will groan in every range but it will move. High range is only good for traveling on flat ground.BTW, the fluid is not low.

 

[crashz]

How old are the filters and fluid? Could your filters be a little loose and sucking air?

High gear is really only used on flat surfaces, like traveling on the road, but I would expect that in Low, the tires should spin. Even in Medium 2wd, the tires would spins with some effort.

I'm wondering if the charge pump is starved due to air or clogged filters.

 

[dfkrug]

BIG: does the tractor pull OK in reverse? If it is OK, then I would look into the FORWARD RV.

Your tractor uses 2 hi-pressure relief valves (4000psi), easily accessible. The FORWARD RV may have dirt in it, or a cracked spring. Easy enough to pull it and look.

If both forward and reverse are weak (low range), then you have a bigger systemic problem with the HST. I hope the fluid is clean, and the suction screen not gunked up.

 

[LittleBittyBigJohn]

I don't have specific experience with your machine. But I do with a similar sized machine, and had the same complaint. For me, I was trying to use it like a big construction machine, attempting to drive forward while taking a bite from a pile. That caused there to be enough weight on the tires to create enough traction that the hydro drive could not overcome it and would bypass. It also caused too much force on the loader. The loader is actually pushing the bucket forward, so you end up trying to push forward with your wheels and backwards with the loader and it cancels out and causes you to say bad words. Check out the video below, Tim explains it pretty well. When I started releasing the forward peddle while lifting a little then alternating back and forth it made a huge difference. I can get big overflowing buckets of material relatively easily with most types of material.

If this is a new issue and you know you have developed a problem then I'm sorry to have wasted your time.

 

[BigDogues]

Thank you for the video. I would highly recommend bew tractor owners watch it. However this is not the problem I have. It’s really a low gear push that just isn’t making it. I think the best way to describe it is trying to load or work in medium or high gear. The force that you might expect is just not there. Plainly put, it pops off way too early.

 

[BigDogues]

BIG: does the tractor pull OK in reverse? If it is OK, then I would look into the FORWARD RV.

Your tractor uses 2 hi-pressure relief valves (4000psi), easily accessible. The FORWARD RV may have dirt in it, or a cracked spring. Easy enough to pull it and look.

If both forward and reverse are weak (low range), then you have a bigger systemic problem with the HST. I hope the fluid is clean, and the suction screen not gunked up.

I will look into this. Sounds like a good place to start. My tractor has less than 300 hrs. I’m going to acquire a gauge and a line to check the pressure. I don’t think anything is gunked up. I did my first fluid change as soon as the break in period was over. However that was years ago and I do plan to do another fluid exchange very soon.
Thanks for your reply.