e70 cat, one side works the other doesnt

[muddstopper]

If I can get my son to come up tomorrow, I might go and try to do a little checking. That proportioning reduceing valve should have a electric solenoid on it. Could be a rat attacked wire chewed. Like you, I have read a bunch but I havent found anything to really give a clue as where to start looking. Not being familar with this type of equipment, even knowing whats wrong, you still have to find where its mounted. I'll do a leaf cleaning and check any solenoid wires. I find it hard to believe that a pump could fail just setting being unused, so its got to be something simple.

 

[oldnslo]

Mudd,
a couple of other things to check if your son shows up are:
1) If you operate one of the functions that are dead does the engine or pump change sound?
1a) Do either of the pump cases get warm quicker than the other? On a Failing piston pump the case will get hot.
2) If you can determine which valve bank is not functioning check to see if the tank line on that valve get warms or feels like fluid is passing through it while you are trying to operate a function. No movement should be no flow and no temp change. Flowing oil and temp rise would point towards the system relief on that valve section by passing flow. In theory these valves should rarely pass oil since they are there to clip spikes and as a safety if the control on the pumps fail.

Yes check the wires since we all know that mice/ rats, etc.. love wire insulation. I doubt it is the prop'l reducing valve since in following the schematic I believe this controls both pumps. In theory if one works the other should also.

Can you use the hoe to lift the track that won't turn off the ground and then try to drive? If this track now turns that would tell you that the valve is getting a pilot signal from the joystick / foot pedal and the pump probably is not bad if it passed the heat rise test in step 1a.

Wish I was few states closer because this has me intrigued.

 

[muddstopper]

Wish I was few states closer because this has me intrigued.

careful, I just might spring for a plane ticket. LOL
Son is a no show today, he had a couple trees fall at his house and is cleaning up the mess. With the storm heading my way, If the weather service makes up its mind, it looks like I might have some house guest in a few days, so dont know when I will get back to the machine.

As for symptoms, when I was trying to operate the machine, it seemed to me that the motor wasnt rev'ing up, I kept reaching for the throttle lever. No lugging of engine operating the side that does work. Model on this machine is e70, not e70b. Looks like throttle is set by cable so I aint sure the schematic we are looking at even applies. I should have taken more time looking at the machine when I was there, but I was disappointed it didnt work right and just got off it and left. Machine isnt going anywhere anytime soon, so I will just wait until I have more time to revisit it.

 

[oldnslo]

According to this link the E70 ended production in 1990 and it also had mechanical implement controls. If that is true the schematics we have been looking at are not correct.

Caterpillar E7 Midi Excavator - RitchieWiki

P.S. This old man doesn't fly, he drives everywhere.

 

[muddstopper]

The serial number on this one is 3cg, so I guess its 1989 or older. I didnt think the schematics where correct, to many things just didnt look right. I wasnt sure, because all I did was glance inside at the valves and pump. I'll have to do some searching and see if I can find the correct schematics. Mostly, I just need to find the time to fool with it.

 

[oldnslo]

If I was to guess the E70 probably has a mechanical horse power & load sense control system on the pumps with similar size pumps & cylinders. This is based on the very similar operating specs.

Hope Irma doesn't cause you to much trouble

 

[muddstopper]

Weather man is saying the eye of the storm is going to miss us by a big amount. Early in the week they had us dead center. I expect lots of rain, getting pretty cloudy outside now. Probably get some wind gusts. Always the possibility of a tornado spinning off the main storm. I feel pretty safe where I am at. Just hoping for the safety of other folks. Chain saws are sharpen with plenty of mix and bar oil. Extra gas and diesel in cans and plenty of food in the pantry. Every time the wife goes to town she comes back with a $100 worth of groceries. Got plenty of milk and bread, I should eat good for several weeks.

 

[muddstopper]

Well, its been awhile since I started this thread. The owner of the machine passed away this week. I got a text this morning to make an offer if I was still interested in buying it. I had pretty much gave up on even fooling with it, and I never went back to try and trouble shoot. I need a track hoe now, as I am planning on putting in a 1000ft driveway to where I am planning on building a new house. Been getting road prices in the $15k range which sort of makes buying a trackhoe a little more agreeable. Knowing the machine is old but decent undercarriage and not a lot of slack in the boom, but with a unknown hyd problem, what might be a decent, I wont regret offer.

 

[oldnslo]

That is question that I can't answer for. The unknown hydraulic problem could be $100 fix or $5,000 fix.

 

[Fallon]

How much does it weigh * scrap steel prices.