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CATT 299D XHP No Hydraulics

S.Fox

Active Member
Joined
Jan 6, 2026
Messages
30
Location
Georgia
CAT0299DAJST01268 Give the information I can so maybe this will help other also if can figure it out.
Lost all hydraulics while working. When it happened was moving some items with grapple and machine came to a stop. No movement forward or backward. For a minute I had a enough hydraulics to release the grapple and it lifted very slow and went down then would not raise again.
Items checked and the work preformed so far. Fan not turning when engine running. Check to make sure Fan was not locked up it is good. When ahead and checked and changed hydraulic filter.( old one did not look bad. All research I did pointed to the coupler. So ordered couple and had a mechanic come out and pulled the engine. NOPE coupler was not bad changed it anyway. Also put the old coupler on the pump while engine was out and trund it. Was not free spinning had some resistance. Put all back together and tried again still nothing. Separated the two pumps. I turned the engine with a ratchet while he tried to hold the enter splins with a large screwdriver nope could not hold it. (Possibly telling me that shaft may not be broke) turned the back shaft with pliers and had some resistance and did not feel broke.
Myself and the mechanic are both lost need some help.
 

HarleyHappy

Senior Member
Joined
Sep 30, 2020
Messages
3,444
Location
So NH
Occupation
Welder/Mechanic
I would assume you have checked the hydraulic lock out solenoids.
What if any pilot pressure and is there a pilot return filter?
 

S.Fox

Active Member
Joined
Jan 6, 2026
Messages
30
Location
Georgia
Have you checked for anything electrical/electronic related.?
Post a photo of the dash panel in the upper RH corner of the cab. You may be lucky and find that you can access Diagnostic Codes without ET.
1000011533.jpg
 

S.Fox

Active Member
Joined
Jan 6, 2026
Messages
30
Location
Georgia
No have not really looked into a lot of electrical because of no warnings or codes that came up and everything i have read said the fan runs when you start it no matter what unless you have hydraulic issues. (Coupler) which it is not that.
 

S.Fox

Active Member
Joined
Jan 6, 2026
Messages
30
Location
Georgia
Did it stop suddenly like the parking brake applied or slowly lose hydraulics and stop?
It just stops the hydraulics on the grapple still worked but very slow for just a few seconds long enough for me to lift and drop the log and then lowered it then would not move.
 

Nige

Senior Member
Joined
Jun 22, 2011
Messages
38,643
Location
G..G..G..Granville.........!! Fetch your cloth.
OK, so you have the Advanced Display. If you get into the service menu does it show anything for Logged Events and/or Logged Diagnostic Codes.

Have you cut open the hydraulic filter to look for particles.?
Is the emergency lowering handle in the correct place.?

If nothing shows from any of the above then maybe it's time to break out the pressure gauges.
 
Last edited:

Nige

Senior Member
Joined
Jun 22, 2011
Messages
38,643
Location
G..G..G..Granville.........!! Fetch your cloth.
It just stops the hydraulics on the grapple still worked but very slow for just a few seconds long enough for me to lift and drop the log and then lowered it then would not move.
So if I understand you correctly the implement hydraulics don't stop completely, they just operate very slowly. What about the drive function F->R. Does it work OK.?
 

S.Fox

Active Member
Joined
Jan 6, 2026
Messages
30
Location
Georgia
So if I understand you correctly the implement hydraulics don't stop completely, they just operate very slowly. What about the drive function F->R. Does it work OK.?
Not nothing works now. When it first stop moving the grapple moved slowly for just a few seconds now no movement on anything. No real evidence of a lot of metal in the filter that would suggest massive failure. I will check on the codes but I am leaning towards the gear pump. It supplies hydraulic fluid to everything the hydrostatic pump and work tool pump
 

S.Fox

Active Member
Joined
Jan 6, 2026
Messages
30
Location
Georgia
Try this for testing the implement relief valve.
Would have to get the tooling from the mechanic. I do have a question these test require you to disengage the parking brake but the fan runs on hydraulics without the brake disengage. So if there is no fan running and no fluid coming to the hydraulic filter is this test necessary?
 

Nige

Senior Member
Joined
Jun 22, 2011
Messages
38,643
Location
G..G..G..Granville.........!! Fetch your cloth.
For a minute I had a enough hydraulics to release the grapple and it lifted very slow and went down then would not raise again
That would be the hydraulic accumulator discharging.

I did ask earlier about the emergency lowering valve position but I don't see any reply. The handle is on the rear firewall of the cab.

1779899407218.png
 

cat262c

Member
Joined
Dec 27, 2023
Messages
12
Location
Hawaii
CAT0299DAJST01268 Give the information I can so maybe this will help other also if can figure it out.
Lost all hydraulics while working. When it happened was moving some items with grapple and machine came to a stop. No movement forward or backward. For a minute I had a enough hydraulics to release the grapple and it lifted very slow and went down then would not raise again.
Items checked and the work preformed so far. Fan not turning when engine running. Check to make sure Fan was not locked up it is good. When ahead and checked and changed hydraulic filter.( old one did not look bad. All research I did pointed to the coupler. So ordered couple and had a mechanic come out and pulled the engine. NOPE coupler was not bad changed it anyway. Also put the old coupler on the pump while engine was out and trund it. Was not free spinning had some resistance. Put all back together and tried again still nothing. Separated the two pumps. I turned the engine with a ratchet while he tried to hold the enter splins with a large screwdriver nope could not hold it. (Possibly telling me that shaft may not be broke) turned the back shaft with pliers and had some resistance and did not feel broke.
Myself and the mechanic are both lost need some help.
Hi did you figure out the problem with your cat losing all Hydraulics? I'm having the same issue on my 262C
 
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