swing motor acting up

[uffex]

Ok take care, no doubt catch up at some stage

 

[jhexjd]

so i capped off the big line, stuck the small line into my container, started the machine andgot no oil coming out. so i guess this elemenates the control block completly (correct me if im wrong) so now ill bust apart the swing motor and see what i find there

 

[uffex]

Good day JH
I would expect a small cross over to the case drain but from your post it sounds excessive, the two possibilities are the lens plate and piston-cylinder leakage.
Good luck
Uffex

 

[jhexjd]

so just out of curiousity can anything happen to the case where the oil goes through into the motor

 

[uffex]

Good day
Both case and refill pressures are low, I would not expect to see any defect.
Kind regards
Uffex

 

[jhexjd]

so i did find damage in the swing motor. the one friction pad was warped and wore off on the outside edge. one of the plates that go against the friction plate has damaged tabs on it. it seems like the brake maybe had to help stop the swing at some point. the pistons were just outside the good range as near as i could tell but a couple are fairly loose in the slipper. the lens plate is scratched . it apears some filings got loose some where. also the shaft has about 3/16 of a turn play. so im not sure what all to change maybe bearings to?

 

[jhexjd]

actually as far as that goes even the case has a scratch sort of wore into it so if that is an issue then im leaning towards popping in a reman motor however not really knowing much about this i would appreciate other opinions
thanks in advance

 

[John C.]

You should find an experienced mechanic to assess the damages.

I don't know if you can find a reman for that machine.

 

[jhexjd]

this is probably a good idea. my dealer does have reman in stock

 

[uffex]

Good day JH
Reman would I believe be your best option please do not overlook to bleed the motor when you rebuild.
Kind rehatds
Uffex

 

[jhexjd]

so after checking pistons again with a micrometer i find that there is actually no play in them which leaves me very confused . so my question is#1 can the lens plate cause leakage #2 can anything else like crossover relief valves or makeup check valves cause leakage . i know im second guessing myself but somethiing doesnt seem right here and i cant get a hold of anybody to look at this thing.

 

[John C.]

If the seal plate at the open end of barrel and the brass on the barrel itself have scratches or scores that can be felt with your finger tip rubbing across it means the plate and barrel are junk. If you can see the marks and not feel them, then it is likely that the two surfaces can be lapped smooth and be reused. I don't recall if that swing motor has brass liners on the barrel assembly but any marks in those liners mean the barrel is junk. If there is any play in the slipper feet at the bottom of the pistons, then they are junk. If there are any marks on the swash plate that can be felt, then it is junk. Odd wear patterns on the brake steels and frictions usually point to them being put in wrong or falling out of place when the motor was assembled. Since they only engage when the house is already stopped, they should not show any wear at all.

Your best bet is to put it back together and get the exchange unit.

 

[uffex]

Good day
As I understand the situation you have a number of options open to you, take your motor to a repair specialist ask for it to be checked out - Go for the reman motor - repair your own motor with a repair kit .
Much depends on how confident you are in taking a step. One point is that we should not overlook how many hours has the machine. Normally one can expect a motor to last about 10.000 hours however some have been subject to reverse stopping on a frequent basis and this can shorten the life considerably.
If you make a search for piston motor - pump repair you can find many videos on youtube some give good advice others are a little short of knowledge. Eaton hydraulics also publish trusted repair information.
One point for sure you will know your machine pretty well by the time you have it working good.Kind regards
Uffex

 

[John C.]

There are no repair kits for these motors. Parts are all ordered individually. I have never trusted independent repair shops for this kind of work on brand name construction machinery, particularly Komatsu. Hydraulic component life is tied to oil cleanliness and keeping temperatures within manufacturer's specifications. I have multiple machines in my territory in excess of 15,000 hours. You can do what you want but most people opt to keep machines earning revenue so franchised dealership reman units are the normal repair option taken. You can repair it yourself, but then you get to live with the future expenses that may incur.

 

[jhexjd]

thanks for the advice. im sending it to the mechanic i always deal with and he will advise me on how to procede

 

[jhexjd]

so i got my swing motor back popped it on and its doing the same thing way not as bad but same thing . so i hooked up some guages and found that there is close to 600 psi at the swing brake release line and at the valve spool cap . then i took off the spool cap and found everything in good shape no scratches on the spool or anything. so now im stuck again . could this be a relief valve problem by any chance? could my joystick be acting up? could there be too much slop in the gears that would cause them to catch on each other. any advice is appreciated thanks

 

[jhexjd]

fooling around with it a bit it seems like the swing brake works too good like its applying too fast or something

 

[uffex]

Good day
As I interpret your post you have pressure of 600 p.s.i. at both the spool cap and the brake release line, in normal circumstances this should be about zero. As you report this pressure is both at the brake release line and the spool cap would cause the machine to swing under power of its own accord as soon as the control lock out has been activated unless that pressure is sitting at both sides of the spool. I suggest you check the pressure at both swing left and right, a combination of pressure would indicate a fault within the illustrated manifold.
Please see matchedKind regards
Uffex

 

[jhexjd]

sorry sir i should have clarified that that pressure is not there till i move any joystick for the brake line but it goes away as soon as i release it and same thing for the spool cap pressure as soon as i move the handle its there but when i release it it goes away right away i believe this is how it should work but please correct me if im wrong

 

[uffex]

Yes Sir, that is correct, it is how it should be.
Kind regards
Uffex