I have a 04, 953c bbx prefix. Travel speed seems slow in both speeds, it does get faster after oil warms up, but still feels weak under load. All cat oils, hydraulic oil is the advanced 10. My question is, should I be running specific filters for the hydraulic system? I am currently running whatever the parts guys at cat give me. I know some older machines don’t like the new higher micron filters. Anyone else have this issue? Thanks!
Do you have any active Diagnostic Codes.? Regarding you question on filters what Part Numbers of filter do you have in the hydrostatic side.?
No codes, and I’ll get you those part numbers. Loader is on a job right now. It has 2-3 spin on filters and also the tank filter. Is there a specific filter you are looking for? Implement and drive pump is shared on that machine is why I ask? Thanks!
The filters on the hydrostat side more than anything else. There are S/N breaks but the charge filter seems to be a 225-4118 which is listed as Ultra High Efficiency and the case drain is a 209-6906. odes the illustration below show the filter installation you have.? I assume that you don't do oil analysis. Have you ever cut any filters in the hydraulic/power train side to look for particles when you PM the machine.?
That is the set up that I have. I have not pulled any samples. I changed the fluid to the advanced 10 about 6 months ago along with filters. It did help some, however now when the oil is cold it seems slower than before, but a little better than before when hot. The engine is bogging down a bit when under load, it’s about the same if I’m pushing 10 yards of dirt or 2 yards. Checked high idle and is spot on 2150rpm. I haven’t watched rpm while under load. Do you happen to know what range that should be?
This is one that ideally needs input from HEF’s resident Cat TTL expert. Hopefully he sees this and responds.
Just checked and filter part numbers are correct. I’m due for maintenance and can pull samples. I’m not sure if this could be related but the machine has never started first crank unless warm, and that’s only sometimes. I’ve owned it since 7k hrs and currently has 8500. I’ve tried priming the filters before starting and still won’t start first time. The sluggishness has been maybe the last 600- 700 hrs. It uses a little oil, maybe a quart every 2 weeks or so 70-80hrs. Thanks
Quick and dirty test is to monitor high idle rpm at implement stall, ie curl the bucket back and hold it against the relief valve. RPM should not go below ~2050 RPM. If it does, it's looking like an engine problem, possibly fuel related. When working the machine, RPM should not go below 1800.
Welcome to the Forums LCd! You have some very good mechanical members giving you advice.
Thanks everyone! I’m out of town for a few days, I’ll try some of those test when I get back and let you know.
Yes sir! I had an old 943 that was having transmission issues, and was able to resolve it by reading through these threads! Thanks for what you all do!
I did the curl back test and when cold the engine will drop to 1950rpm, when warm it will only drop 30ish rpm. I allowed the engine to get to operating temp and then tracked forward in low range. it drops the rpm to 1780-1800 rpm (just tracking on flat ground with bucket empty.) After working the machine for 30-45 minutes it will track just fine without dropping rpm. However it still feels weak under load (pushing dirt etc) thanks! Also outside temperatures were around 30 degrees
My gut feeling is that you have an engine power problem, rather than a transmission problem. If I was there in person, I would probably start by quickly running through the transmission calibrations to make sure, but I'm not. If you have pressure gauges, check the fuel pressure at the point in the drawing below. You need ~60 psi. If you don't have gauges, inspect the fuel system from the tank checking for blockages etc. Obviously, replace the fuel filters.