J
JohnBarlow
Guest
I have a really old backhoe (1971 Chamberlain Mk3 industrial, Australian made). Recently it has started to loose hydraulic power after a short period (half an hour ?) of operation.
It has many faults, but I would like to find a "main culprit" to attack and fix, as I can't justify fixing everything. I need some ideas/assistance to select/find the main culprit.
When cold the system seems pretty good. After running for a while it starts to have less hydraulic power, and lifting the front yard bucket requires pulling the lever, wait three seconds, release the lever, wait three seconds, pull the lever ... (etc.) - it will only lift the bucket for a short time period (and only then an inch at a time).
Possibly associated with the problem is an increasing tendency for the rear boom (main lifting ram) to lower the boom towards the ground (presumably oil seeping from one chamber into the other chamber of the ram, no huge oil loss onto the ground) - although it has always (fairly slowly) lowered itself towards the ground, just now it is notably worse.
The hydraulics don't have much (any ?) power at low engine revolutions, so the engine is always set to rev fairly hard to achieve work.
When I notice the hydraulics low on power I can touch & hold (but it isn't comfortable) the hydraulic return line (which goes into the filter just before entering the tank reservoir).
I think the problem might be either:
1) blocked hydraulic oil filter (changed it again last week)
2) engine low on torque (head gasket leak, etc.)
3) blockage in some of the hydraulic pipes/controls
Known faults:
Head gasket leakage (gas escaping around head bolts, excess pressure in crankcase).
Diesel pump leakage (accelerator gland leaks constantly).
Front yard bucket rams leak hydraulic oil (now at a rate of a drop every 8 seconds).
Rear supports (sprags ?) leak oil.
Hydraulic pump might leak oil (but it seems to mostly be the supply pipe).
Hydraulic oil supply pipe (corrugated plastic, about 2 inch internal diameter) leaks a bit at both ends. How do you clamp a spiral-corrugated plastic pipe ?
Diesel (overpressure ?) return pipe appears crimped mid-pipe.
... and lots more issues (but heck, it is fun to use, and I can't afford to buy a replacement).
Do people think it is a worn out engine (Perkins 4-236 deisel), or a hydraulic blockage ? I am leaning towards the engine as the problem, as the hydraulics work pretty good cold, but I guess if the hydraulic return is partly blocked the pump could be working overtime pushing the oil around without me even trying to use the controls, and hence getting the oil really hot (hence thinner, rear boom lowers quicker, etc.).
John Barlow, Bega Valley, NSW, Australia
(owner builder doing a straw bale house)
http://www.guru.com.au/farm/
It has many faults, but I would like to find a "main culprit" to attack and fix, as I can't justify fixing everything. I need some ideas/assistance to select/find the main culprit.
When cold the system seems pretty good. After running for a while it starts to have less hydraulic power, and lifting the front yard bucket requires pulling the lever, wait three seconds, release the lever, wait three seconds, pull the lever ... (etc.) - it will only lift the bucket for a short time period (and only then an inch at a time).
Possibly associated with the problem is an increasing tendency for the rear boom (main lifting ram) to lower the boom towards the ground (presumably oil seeping from one chamber into the other chamber of the ram, no huge oil loss onto the ground) - although it has always (fairly slowly) lowered itself towards the ground, just now it is notably worse.
The hydraulics don't have much (any ?) power at low engine revolutions, so the engine is always set to rev fairly hard to achieve work.
When I notice the hydraulics low on power I can touch & hold (but it isn't comfortable) the hydraulic return line (which goes into the filter just before entering the tank reservoir).
I think the problem might be either:
1) blocked hydraulic oil filter (changed it again last week)
2) engine low on torque (head gasket leak, etc.)
3) blockage in some of the hydraulic pipes/controls
Known faults:
Head gasket leakage (gas escaping around head bolts, excess pressure in crankcase).
Diesel pump leakage (accelerator gland leaks constantly).
Front yard bucket rams leak hydraulic oil (now at a rate of a drop every 8 seconds).
Rear supports (sprags ?) leak oil.
Hydraulic pump might leak oil (but it seems to mostly be the supply pipe).
Hydraulic oil supply pipe (corrugated plastic, about 2 inch internal diameter) leaks a bit at both ends. How do you clamp a spiral-corrugated plastic pipe ?
Diesel (overpressure ?) return pipe appears crimped mid-pipe.
... and lots more issues (but heck, it is fun to use, and I can't afford to buy a replacement).
Do people think it is a worn out engine (Perkins 4-236 deisel), or a hydraulic blockage ? I am leaning towards the engine as the problem, as the hydraulics work pretty good cold, but I guess if the hydraulic return is partly blocked the pump could be working overtime pushing the oil around without me even trying to use the controls, and hence getting the oil really hot (hence thinner, rear boom lowers quicker, etc.).
John Barlow, Bega Valley, NSW, Australia
(owner builder doing a straw bale house)
http://www.guru.com.au/farm/