David Boreham
Active Member
It seems that I'm a proper member of this group now because not only to I have a min-ex, but now I have a hydraulic problem
Would be grateful for some fault isolation advice. My Volvo ECR38 has one track that is not working quite right. I've done some Internet research and gathered the following info:
1. The problem doesn't seem to be related to oil temperature. It happens right from cold, and when hot.
2. The problem only affects one direction. The other direction seems fine.
3. The problem occurs on both high and low speed.
4. I've eliminated simple "mat stuck under the pedal" causes by removing the mat, cleaning dirt from around the pedal, checking there's no rocks wedged under it, etc.
5. Engine RPM drops when power is demanded of the lazy track, as if it is supplying power, regardless of whether it turns strongly or not.
6. Trying various things with the tracks off the ground, I get the impression that the bad track will run properly, but it sort of takes fiddling with the pedal/lever. For example if you ease it slowly in the "bad" direction, the track seems to leap into action and run strongly for a few seconds, but if you keep pushing the lever further forward it seems to lose momentum and slow down. Once it gets slow it never speeds up again until you stop it, or perhaps run it a bit backwards which seems to "wake it up" again.
7. The "good" side lever feels a bit different from the "bad side" -- but not in exactly a way that would account for the difference in behavior directly -- e.g. it isn't that the bad side just can't be pushed full travel. But it just feels different like the mechanical mechanism underneath, valve spring rate and what not is not the same. Unfortunately I don't have a good machine to compare.
Otherwise the machine seems fine. Hydraulic fluid is clean, full, all other cylinders work ok. It has ~1000hrs and is 9 years old.
Would be grateful for some pointers on where to look to diagnose this further. I have the service manual. It is silent on this, unless I've missed that section in the 500 pages...
Would be grateful for some fault isolation advice. My Volvo ECR38 has one track that is not working quite right. I've done some Internet research and gathered the following info:
1. The problem doesn't seem to be related to oil temperature. It happens right from cold, and when hot.
2. The problem only affects one direction. The other direction seems fine.
3. The problem occurs on both high and low speed.
4. I've eliminated simple "mat stuck under the pedal" causes by removing the mat, cleaning dirt from around the pedal, checking there's no rocks wedged under it, etc.
5. Engine RPM drops when power is demanded of the lazy track, as if it is supplying power, regardless of whether it turns strongly or not.
6. Trying various things with the tracks off the ground, I get the impression that the bad track will run properly, but it sort of takes fiddling with the pedal/lever. For example if you ease it slowly in the "bad" direction, the track seems to leap into action and run strongly for a few seconds, but if you keep pushing the lever further forward it seems to lose momentum and slow down. Once it gets slow it never speeds up again until you stop it, or perhaps run it a bit backwards which seems to "wake it up" again.
7. The "good" side lever feels a bit different from the "bad side" -- but not in exactly a way that would account for the difference in behavior directly -- e.g. it isn't that the bad side just can't be pushed full travel. But it just feels different like the mechanical mechanism underneath, valve spring rate and what not is not the same. Unfortunately I don't have a good machine to compare.
Otherwise the machine seems fine. Hydraulic fluid is clean, full, all other cylinders work ok. It has ~1000hrs and is 9 years old.
Would be grateful for some pointers on where to look to diagnose this further. I have the service manual. It is silent on this, unless I've missed that section in the 500 pages...