Cat 312 What are the most common culprits that cause this? It's not dirt under the pedal. Thanks, Rob
Out of curiosity ..... Which side ? ...... its been sugested to me that the o-rings in the rotary manifold are now hard and do not seal tight, now bypassing especially when it gets up to temp ....... I'm waiting to hear the feedback on this one as well
Is it only weak on one side going one way. If you swing the house around, does it change sides or directions. Have you checked pressure with a gauge. The swivel seals are one culprit by it can also be the stroke on the main control valve spool or a weak pump. It sounds like you already eliminated the cheapest fix. Probably next is to put gauges in and check pressures on each side in each direction. Many times the gauge won't tell you much but it is a cheap fix is the relief on one side is low. After that I'd probably pick up each track and check cycle times. If a pump is slow, it should show up there. From there I'd probably pull the swivel and check seals. Good Luck!
not a heavy equip tech by anyones standards but have seen 2 690b john deer hoes with the inside of a hose going to the track motor collapsed inside and cause such a problem
I have a CAT 350 that had a weak track on one side. I had it checked out and after 2 service truck trips of trying other things, the problem was the track motor. Be warned though, if there is a weak part elsewhere in the system it can show up soon after the repair. After getting my track motor replaced, like the day after, I had that same side come to a grinding halt, there were some final drive gear teeth that had broken off and seized up the final. Now that was an expensive repair
Swivel is a likely cause but check the other things first to confirm it. What side is weak? Is it weak in both directions? If weak in one direction swap the cross over reliefs on that side. See if the weak direction swapped. Does it miss track? if yes, does it miss track while moving a function like the bucket? Checking pressures at the pumps and the motors will tell you what is going on.
Thanks for the replies. Gives me some ideas on what to check. I probably don't have the right adapters for a gauge. Are the relief valves on the valve bank or somewhere else? 'Spose I could get some info from the local dealer, they're pretty good at trying to help. Rob