Weird Hydraulic Issue cat 315CL

[floridamechanic]

test results, teeth stuck in ground, stick in has power and medium howl, stick out has very very little power and loud howl, swing left or right has howl but no ways as loud as stick out, more than normal though, and yes big thanks to Mr. Nige for the info, been studying it, liquid filled 10k pressure gauge, going drain tank an pull screen in morning to eliminate supply questions, guy at cat told me #2 boom spool also, is that the one on page 9 #18 on schematic Mr. Nige sent? Lord this stuff was easier 20 years ago lol

 

[funwithfuel]

It wasn't easier, our eyes just worked better. Dont confuse boom 2 with stick 2 . Stick 2 gets oil from pressure reducing valve at boom priority valve. If that valve sticks open it drains the oil off , effectively neutralizing the spool and bleeding servo to stick.
Either way, based on your results. I'm leaning hard towards regulator. I think your pump is stuck in Q-min . It's a bit difficult to troubleshoot a negative control system with the regulator controlling leak to tank. The best I could suggest would be to swap the pigtails from AA to BB. You would be stuck in Q-min in all but boom and stick and straight line travel if you have it. If the problem follows the pigtail, its electrical, if it stays, you're probably going to be looking at the regulator.
Good luck and be careful, things are getting into the area where bad things can happen quick, if you dont think things through.

 

[floridamechanic]

do not understand Q-min, facing pumps from ground are what you are calling regulators the valve with pigtail harness? so swap them?

 

[funwithfuel]

Sorry, Q-min means minimum displacement. Yes, swap pigtails only, see if it follows. If that doesn't get it, we'll look at swapping regulators.
I'm really surprised none of the CAT guys other than Nige have jumped in. BTW , I tend to lose sight of the obvious. You may want to follow his advice, follow the path of the oil. Start at the suction strainer.

 

[John C.]

You have an arm regeneration valve that allows some of the return oil from the rod side of the cylinder to go into the piston side of the cylinder to prevent a suction on that side when quickly pulling the stick in. It also stops the lag you used to get on older machines when the stick got to the vertical point in its travel inward. There is a possibility that the spool is stuck and is something to check. If it is stuck I could see it causing noise because oil would be fed to both sides of the cylinder if stuck in stick in position. I see the spool in the schematic but don't know where it is on the control valve. The other valve to check would be the load lock valve or anti-drift valve as they call it on the rod side. Since you have noise with no debris you have what we call a gremlin. They take time to find and usually cost a fair amount of money trying to identify it but when done you will be tapping yourself on the head that it shouldn't have been that hard to find. Sometimes they go away and you never know for sure why.

 

[floridamechanic]

thanks to everyone and will do as you advise and start with strainer and the aa--bb then stick 2 then anti drift, learned a long long time ago not to whine just step up and handle what is necessary but at almost 70 whining sure looks god lmao

 

[floridamechanic]

cleaned screen then thought thiis video of what unit is doing may help

 

[funwithfuel]

In the second video, what function are you pulling to get that reaction. I only "see" the left hand pump stroking up. I watched it several times. You can see your load sense line stiffen up as well as pump discharge off the top. The right side doesn't behave the same.
The first video really illustrates what challenges you're facing. Do you have enough harness to swap pigtails from aa to bb. In the video, it looks like a challenge.

 

[funwithfuel]

The other thing I see in the video is that boom down struggles until you bring in extra oil from the arm circuit. Is that a fair statement?

 

[John C.]

What strike me is the boom continuing to go down after letting go of the stick function. Are you still holding the boom down at the same time.

The noise sounds like a heavily loaded pump and not a broken pump. "Gremlins"

 

[floridamechanic]

Yes holding boom down and bumping stick out, then hold boom down and give it full stick out, yes boom struggles til hit stick out or bucket curl, stick in or bucket out does not add pressure to boom down, just got in been on dozer all day, doing stick out in the pump video , makes loudest noise

 

[floridamechanic]

will go try AA to BB, if not long enough will adapt

 

[floridamechanic]

Ok test results, switched AA-BB, more down pressure for sure, open function raise about 2 foot then hold function full open will struggle and creep up with very very very little pump noise then hit spot and climb way up, still have all functions and opening ftick out will still greatly assist boom down, but changing AA-BB gave more down boom pressure,

 

[floridamechanic]

stick out still howls bad

 

[floridamechanic]

pilot pressure is 900, cat says 595 is this part of problem?

 

[funwithfuel]

Sounds like it. Perhaps a drainage issue. 900 , no functions pulled safety lever engaged?

 

[floridamechanic]

no functions pulled don't remember about safety lever but will check, just switched AA-BB back and unit goes up with boom down function, not great but better than 4 inches it was doing, will rise all way without stick out assist, Cold oil? will get back off job tomorrow and work it and get op temp and check pilot with lever down and report back

 

[floridamechanic]

Wher AA and BB hook up are those pressure sensors?

 

[Cmark]

pilot pressure is 900, cat says 595 is this part of problem?

No, it isn't right. Has anyone been tampering with it? Wrong pilot pressure can cause all sorts of weird problems.
I would;
A. Verify your gauge is correct.
B. Change the pilot filter.
C. If it's still high, adjust it.

 

[floridamechanic]

Have changed filter, owned for year and half no issues, will change to another gauge and retest tomorrow