Cat IT28 hydraulic drift

[Pete w]

Good morning,
So im having a bit of an issue with this dagone thing...
Cat IT28G 8CR00481
It previously on drifted down on the tilt. Now its drifting both ways.
So...when it was only drifting down i dug into it. Found that the relief valve were corroded almost in half. Replaced those and repacked one cylinder. It looked as if someone had been in there and had ground down the inside of the barrel. I told the boss the new packing kit may or may not hold on this thing but he said to continue. The other cylinder had catastrophic failure. Metal inside and destroyed. Replaced with a good used. Drained hydro and replaced filters, drained lines.
No more drift. Beautiful. Went on on a job for a few days...drift is back but as i said before now it drifts both ways. Could it be the cab control at this point? i find it unlikely that both cylinders failed again although i was already questioning the one...

 

[Mobiltech]

It only takes one to make it drift. If you had a lot of metal in one cylinder chances are there was metal in the lines which could also destroy your seals and relief valves.

 

[Nige]

You said one cylinder looked dodgy when you resealed it. Did you use a standard size seal kit or a 0.030" oversize one.?
The oversize seal kit is a 233-9207 compared to the standard size seal kit which is a 233-9205.

 

[Per Eriksson]

Back to basics, plug the rod end of one cylinder at a time and see if it still drifts, no need to pull **** apart before you know where the problem lies.

 

[Pete w]

You said one cylinder looked dodgy when you resealed it. Did you use a standard size seal kit or a 0.030" oversize one.?
The oversize seal kit is a 233-9207 compared to the standard size seal kit which is a 233-9205.

Standard, i didnt see that they offered a oversized kit. I may have to go that route.

 

[Pete w]

Back to basics, plug the rod end of one cylinder at a time and see if it still drifts, no need to pull **** apart before you know where the problem lies.

I did initially but havent repeated the process yet..I have no motivation to work on the hydraulics of this thing again..haha

 

[Pete w]

Ok, well. This thing was out pushing snow over the weekend. Just got it back in here and now i have no tilt back. It jumps but doesnt move. And i have a bit of tilt down. It seems the functions dont want to work either without giving it a bit of pedal. Boom up and down seems to be fine. Steering and braking seems to be fine. I dont have a book as of yet so im unsure of what my pressure readings should be. I was going to take the valve body off and take it apart and clean it to see if there is any debris causing a stick open or something. Any help and direction would be appreciated as without any numbers im flying in the dark with just removing and cleaning.

 

[Nige]

Here's the Hydraulic System Test & Adjust if it's any help.

 

[Nige]

I was going to take the valve body off and take it apart and clean it to see if there is any debris causing a stick open or something. Any help and direction would be appreciated as without any numbers im flying in the dark with just removing and cleaning.

While you are in there don't forget to open up and clean all the electrical connectors on the control valve solenoids.

 

[Pete w]

Here's the Hydraulic System Test & Adjust if it's any help.

Thank you Sir!

 

[Pete w]

Found a piece of metal about the size of a grain of rice caught in the tilt spool valve. Thankfully no damage. Also was missing the shims in one of the tilt caps. Fixed all that...same issue. The hunt continues.

 

[Pete w]

Unsure how to insert some pics for your viewing pleasure. But it turned out to be the new to us cylinder recently installed. Bolt came loose from the rod as well as a blown seal. No damage to the cylinder thankfully. Repacked and good to go!

 

[Nige]

https://www.heavyequipmentforums.com/threads/how-to-add-pics-to-forum-posts_update.49267/

 

[Nige]

Or an even easier way provided you are working on a PC or laptop....
1. Open the photo you want to upload.
2. Open the Windows snipping tool.
3. Using the snipping tool select all or part of the area of the photo.
4. Paste the snip to the post where you want to upload the photo.
Simples........

 

[Pete w]