How to increase HST relief pressure on a CK30

tinman955 · Apr 30, 2010

Highbeam said:
SST as in skid steer tractor or SST as in shuttle shift transmission?

Shuttle Shift Tranny

williekioti · Apr 30, 2010

I'm with you tinman, I too prefer the gear. Completely a personal preference though and I understand those that go HST for convienence. I'm a bit old school and like the keep it simple principle. Never had a problem with it not spinnin' a tire, bury the loader too deep and she'd dig her way to China......... ;-)

tinman955 · Apr 30, 2010

Willie thats why im goin SST, I want the ability to pick the right gear and I want to put the most power to the ground. :thumbsup:

tinman955 · Dec 31, 2011

So whatever happened to this thread? Sorry bout bringing it back up but unfortunately I might be buying another tractor that is a cab and they come only in a HST. So did anyone increase the relief setting of their HST for increased performance?

bbse · Dec 31, 2011

No, I still cannot get up that hill. I plan to fix the problem myself as soon as the warranty is up.

Tim M · Jan 1, 2012

Instead of grinding and rewelding I added a small shim to essentially compress the RV spring a bit (so I could easily go back) since I was planning to try and get it "fixed" under warranty. I took a thin flat washer(30-40 mils) and cut a slot so it could be slid in under the spring. I was able to get mine over 4000psi and I had plenty of pedal left. It made a considerable difference. Obviously one needs to BE CAREFUL! Do not do this without a pressure gauge.

Originally my pressure was at around 3700 psi if I recall. In the end my dealer got me a new RV under warranty and my pressure went up to right around 3950 psi. It did make a significant difference.

Tim

dfkrug · Jan 1, 2012

tinman955 said:
So did anyone increase the relief setting of their HST for increased performance?

I forgot that I started this thread, TIN.

Kudos to Tim for making an adjustment, and measuring the pressures,
before and after. I have been meaning to get a 10,000psi guage to
measure multiple HSTs.

I may be quite easy to intall the CK35/CT235 RV in a CK30/CT230 as
well. I don't imagine the part costs very much....

Tim M · Jan 1, 2012

At the time I did check the price was a lot more than I expected. I seem to recall a few hundred dollars.

Here is a picture of my original with the shim:

http://www.superxtune.com/public/RV_280.jpg

Tim

Tim M · Jan 1, 2012

So I just reread a few of the earlier posts.

At the time I was looking into this a few years ago the CK35 had the identical part number for the RV. (or so my dealer told me!)

Has Kioti bumped this pressure up to 4260 psi for the CK35?

Have they changed the HST internals of the CK35 to handle the higher pressure?

dfkrug · Jan 2, 2012

Tim M said:
At the time I was looking into this a few years ago the CK35 had the identical part number for the RV.

Has Kioti bumped this pressure up to 4260 psi for the CK35?

Have they changed the HST internals of the CK35 to handle the higher pressure?

Nice job with the shim. I agree that over 50-75 clams, forget about
buying another RV.

My memory may be faulty but I thought there was a different part # for
the CK35 HST RV. Did someone check their service manual (CK35 or
CT235) for the specced HST pressure?

I don't know about any different internals of the CK35's gearbox, etc,
but if the CK35 has 5 more hp, it would be nice if it delivered more
HST pressure and/or flow. If the HST is exactly the same as the one in
the CK25/30, then the bigger engine is not wasted, however. It should
be able to go faster up hills in the high range.