2006 CAT 287B No Hydraulics ?

[barnfab]

This is a bit weird and I am hopeful someone can help me out. I was running the other day and it started to loose drive and then bucket power and stopped. Still running fine not lights on. I got out and had dumped what looked like a significant amount of Hydraulic Fluid. I figured I had blown a hose or something.

So I lifted the cab and the inside was literally full of years of dirt and oil so I spent the next few hours digging, vacuuming and pressure cleaning to get to the point where I could see what was going on, still expecting a hose to be blown.

Now I can see what is going on and run the machine and nothing appears to be blown and no big leaks, one small one by nothing like what I expected. Hydraulic Tank is still 3/4 full so plenty of fluid and stiull no drive or bucket etc.

One thing it does do now is when I run it and then turn it off I get a loud gurgling sound as though the pump is full of air ?

Is there a way to bleed the pump ?

Any ideas or suggestions ?

 

[kshansen]

Just from the mention of the gurgling noise on shut down I would be looking very close at the suction side of the hydraulics, suction leak letting air into system would be first guess.

Also would be pulling any hydraulic filters and cutting open to see what is in there!

I'll reserve comments on the " lifted the cab and the inside was literally full of years of dirt "!

 

[barnfab]

I'll reserve comments on the " lifted the cab and the inside was literally full of years of dirt "!

Yeah when I saw it I expected the hard lines to be rusted through. I have only had the machine a week or two and did the base line on the engine, greased everything and was doing a list of the seal kits that needed doing. In hind sight I should have had the guy I got it off lift the cab before I bought it. Oh well at least in SOCAL rust isn't a real issue.

I will check the feed lines.

Is there any need to bleed the system ? or will it self bleed based on the tank being higher and gravity doing its thing ?

 

[kshansen]

Yeah when I saw it I expected the hard lines to be rusted through. I have only had the machine a week or two and did the base line on the engine, greased everything and was doing a list of the seal kits that needed doing. In hind sight I should have had the guy I got it off lift the cab before I bought it. Oh well at least in SOCAL rust isn't a real issue.

I will check the feed lines.

Is there any need to bleed the system ? or will it self bleed based on the tank being higher and gravity doing its thing ?

That's why I "reserved" my comments! Now if you said you owned it for ten years......................!

I won't say that bleeding is not needed as I have never had the "pleasure" of working on a Cat 287, company bought a Cat skid steer after I retired! But most hydraulic systems do self bleed.

My main concern would be if it is sucking air it could also be sucking dirt also air in a hydraulic system can be very destructive of some parts. Bubbles popping at high pressures can act like little explosions that damage parts.

Do you at the very least have a operation and maintenance manual?

https://catpublications.com/Search/recall?savedSearchId=122273ce-c03b-ea11-911d-005056a270f1

 

[barnfab]

Yeah hopefully it will be something simple. My previous ride was an 1845C so it was somewhat simpler and less weird stuff that this new stuff

My Vin # - CAT0287BCZSA03469

I have ordered manuals for it should be here today

 

[92U 3406]

IIRC the hydraulic tank on those older B's is mounted above the pump, on the cab side of the firewall between cab and engine. If so, I don't think you've got a suction issue since the tank level is significantly higher than the pump inlet.

So you have zero functions and zero drive at this point? Along with a gurgle sound? Being that it was a rapid, but gradual loss of hydraulics and not instantaneous I think we can probably rule out the pump drive coupling.

First thing I would do is start putting gauges on it, starting with charge pressure because this really sounds a lot like a failed charge pump to me.

The hydraulic oil spill certainly puzzles me though.

 

[barnfab]

Correct the tank is behind the seat just over the pump.

Correct Zero Functions, it was working, lost drive and then lost bucket in the space of about 10 seconds. The gurgle sound is very obvious if you start the machine and then turn it off it continues on after you have shut it off like it has built air pressure.

Once I have the manual I will get a gauge onto it and see what I can see.

Yeah the oil spill was weird, I would have been 100% on expecting to open up and find a hose blow but the more I think about it now the oil was probably low pressure as it wasn't covered and sort of ran out, or it was under the 8" of crap. After looking inside I even started thinking maybe it was just damned up and the oil may not directly relate to the issue but I can see on the ground where it started leaking maybe 5 ft before it stopped. The tank is still 3/4 full so it didn't just keep running out and hasn't leaked since.

 

[92U 3406]

By chance did you happen to notice if the hydraulic fan was turning? I'm not 100% certain on the B's but normally charge oil goes thru the fan motor before it charges the hydrostatic system. If the fan isn't turning at all, you'll most likely be looking at a charge pump/charge pressure issue.

 

[barnfab]

By chance did you happen to notice if the hydraulic fan was turning? I'm not 100% certain on the B's but normally charge oil goes thru the fan motor before it charges the hydrostatic system. If the fan isn't turning at all, you'll most likely be looking at a charge pump/charge pressure issue.

I did not but I was just reading that on another thread so I will check it when I get home.

 

[barnfab]

So I started the machine up when I got back and the fan moves but it seems slow and without power. Now it does not look like some sort of thermally controlled variable rate setup so I am going to guess that this means there is bugger all hydraulic pressure getting to it so it is just lazy looping on what little flow there is.

I ordered a test port coupler so once I get that I will test pressure but it certainly looks like it is pretty much no existent.

Based on what I have read and had posted here it is certainly pointing to the charge pump taking a dump, if that is the case can anyone enlighten me as to an explanation of how that works and what the gurgling sound is ?

Anyone had one fail before ?

 

[92U 3406]

Basically the charge pump is what supplies oil to the other pumps for all hydraulic functions. The hydrostatic system is a closed-loop circuit so the charge pump pressure is what keeps that system full.

I've diagnosed one or 2 that have failed. The gears in the pump chewed the aluminum housing of the pump. Not sure on the B's but on the newer ones the charge oil goes through the filter, then the fan before going to the hydrostatic pumps. If you can trace the lines or review a schematic and can confirm yours is the same way, I'd remove and open up the hydraulic filter to check for debris. Lots of metal/aluminum chunks would indicate there's a good chance the charge pump has failed.

What I can't remember for sure is if the filter is before or after the fan. If its after the fan, you'd have to consider that any debris in the filter could be from the fan motor too.

 

[barnfab]

Ok so if I am reading correctly the Fan is after the Charge Pump but before the Filter meaning if the charge pump failed the Fan may well be full of crap .

 

[barnfab]

Well I got the port adapter and tested the line pressure at the fan test port and it was Zero lol. Thinking it might be a gauge issue I opened the port and oil just dribbled out ... so I guess it is time for a new Charge Pump and then I am guessing I will find the leak when the system has pressure again if I am lucky enough not to have damaged anything else.

Charge Pumps are like $1100 new from CAT or $500 used although I find it interesting that every used one is off a machine with a broken hours meter so they cant tell me how many hours it has. Needless to say I just ordered new to avoid having to do it again any time soon.

 

[Nige]

It might pay you to do a complete clean out of the hydraulic system, especially the pilot side. Who knows where the shrapnel from the old pump may have ended up.? And don’t bank on the filter catching it all.....

 

[Mobiltech]

How do you know the tank is 3/4 full. The sight glass only reads when it’s almost full. The tank is very hard to see into and it has a curved Center section.
Before you do anymore put oil in it until it’s full. The symptoms you describe sound like low oil level.

 

[barnfab]

It might pay you to do a complete clean out of the hydraulic system, especially the pilot side. Who knows where the shrapnel from the old pump may have ended up.? And don’t bank on the filter catching it all.....

Yeah will do a complete flush and new filter, oil is cheap.

How do you know the tank is 3/4 full. The sight glass only reads when it’s almost full. The tank is very hard to see into and it has a curved Center section.
Before you do anymore put oil in it until it’s full. The symptoms you describe sound like low oil level.

I took the lid off the tank and put a light stick in it and could see the oil about 5" down, BUT like everything you have me wondering now so I will double check and make sure it is in fact at that level on not just low and not feeding the pump etc and the real issue being a hose leak that dropped the oil pressure and stopped it pumping which in turn dropped the pressure and stopped the leak .

The Current facts are :
- Machine dumped oil
- Machine lost drive and boom from going to nothing in a few seconds
- Machine had a puddle of oil under it and running out on skids
- Machine was full of crap and most hard lines in belly are rusted.
- Machine runs and sounds normal till I turn it off and it gargles and bubbles
- Fan moves slowly with no real force, fan test port has ZERO Pressure

Things I need to double Check
- Oil level in hydraulic tank to make sure I am not seeing things and fill it up to ensure it is full and do system tests again
- Once tank is full run it again and see if it primes up and oil pisses out of a high pressure hose.

Its funny how when you are not near the machine you second guess everything you were sure of when standing next to it lol

 

[92U 3406]

In all honesty, if you're draining the tank to change the oil, it takes very little time to remove the tank itself and flush it out really good. You'd be suprised at what collects on the bottom of the tanks.

 

[Mobiltech]

Yes please fill tank. Everything you say its doing is what mine does when it blows a main hose and dumps all the oil in about 20 seconds. Its gurgling because its pumping air.
If you're seeing that much oil coming out i doubt your 3/4 full.

 

[barnfab]

Ok so I checked the tank and it was still over the filter. I fitted a new charge pump, fired it up and oil pissed out the drive hose for the right hand side. Of course these are the WORSE hoses ever invented to change so I had to pull the drive motor out to get to the fittings and even then it was a complete PITA ... Got them out, fitted new hoses , tested system and no leaks, drive is back. Now I will flush the entire system, change the filter, fill with new oil and get back to digging.

If I ever meet the CAT engineer who designed the drive motor hose locations and hook up I am gunna beat him ... and for anyone who says they can replace the main drive hoses on a 287B without pulling the drive motor, I would pay $$$ to see that happen as I don't think it is possible.....

Part Numbers used in case it helps someone else are :
Machine 2006 CAT 287B Ser: ZSA03469
220-8127 : Charge Pump @ $1066.88
218-6637 : Lower @ $347.42
218-6638 : Upper @ 358.59
1G-8878 : Hydraulic Filter @$63.67
3096931 : Oil Hydro 10 5 Gal Buckets @$106.66 ea ( 5 Gal Test : 14: 7 Gal for full system )

Now all that being said I still don't completely understand where all the oil came from so have convinced my self the mud and crap was collecting it and the hose was just enough to push it all out and make a bigger mess than what i though. I stopped the machine quick enough ( Charge pump died quick enough ) that the full tank did not drain and created the confusion

Anyway, hopefully that helps anyone who happens to have a similar issue.

I ended up buying a Service Manual as a down load file online which was more of a complete dump out of CAT Software than a Repair Manual but if anyone else needs it I am happy to share so you can save the $$$$ , it was over 200 MB so it aint small and it did have a lot of handy info but is somewhat confusing to use lol

 

[ianjoub]

and for anyone who says they can replace the main drive hoses on a 287B without pulling the drive motor, I would pay $$$ to see that happen as I don't think it is possible.....

I definitely pulled mine to change the hoses. I also welded up a piece to zip tie the hoses to. Chafing is what got mine.