Ever fully closed a grapple in a D?

[y3ll0w]

Got to demo a D series and when the dealer was showing me how to close the grapple the front hydraulic block cracked and begain to leak. The dealer said the D series will do that if the hydraulic system under pressure for too long. After the grapple was closed he kept the hydraulics on for about a 10th of a second. (reaction time to see/feel the grapple was closed)

That killed the idea of a TC right there....

...Unless the dealer is wrong.

 

[y3ll0w]

Just to be clear the leak was not something that stopped when the hydraulic system was shut down. During the fraction of a second it took him to shut off the hydraulics to the grapple a hydraulic hose fitting cracked and the hydraulic distribution block on the loader arm also cracked. The sales man said it would be a couple of hundred dollars just in parts and it was due to the fact that bobcat changed the design of the D and this system was one of the changes.

 

[trlbrkr]

I have the utilityfork on my D
Utility Fork Grapple Attachment - Bobcat Company
-- after spending the morning working with manure - brush and holding the hydraulics open and closed I had no problems?
I wonder if the salesman had it in high flow?
The hydraulics on this machine are great,,from the dripless flat face fittings that are a easy to connect, even after an implement has been sitting in the hot sun. The dump and bucket are powerful at idle with full loads..I am impressed

 

[y3ll0w]

That is the exact attachment, it was not in highflow mode. I knew he had to be wrong.

 

[radman1]

Just to be clear the leak was not something that stopped when the hydraulic system was shut down. During the fraction of a second it took him to shut off the hydraulics to the grapple a hydraulic hose fitting cracked and the hydraulic distribution block on the loader arm also cracked. The sales man said it would be a couple of hundred dollars just in parts and it was due to the fact that bobcat changed the design of the D and this system was one of the changes.

That is the craziest statement I have heard. No way would anyone design a hydraulic system that would self-destruct just because the hydraulic was left on too long. Relief valve should take care of that issue. That is why they have max psi settings of 3000 and "not until it breaks." It does seem weird why 2 different areas both had problems. Defect in the hydraulic system or relief valve? It would be nice to measure what the hydraulic pressure is in the system on that unit.

 

[jmfox]

The dealer said the D series will do that if the hydraulic system under pressure for too long.

This is the comment that needs to be flushed out.

jmf

 

[theoshin]

this is crazy. no hydraulic system is engineered this way.

 

[IslandTractor]

Find another dealer. Do you really want to buy a 40K+ machine from someone with such a poor understanding of hydraulics?

 

[jmfox]

the front hydraulic block cracked and begain to leak.

I'm not sure you can blame the dealer for a cracked block or disclosing his experience. What the dealer maybe saying is that certain parts, e.g. a hydraulic block, are unique to the TC and tend to fail under normal use. Defects are not designed they are unfortunate surprises that need to be fixed.

jmf

 

[y3ll0w]

That is the craziest statement I have heard. No way would anyone design a hydraulic system that would self-destruct just because the hydraulic was left on too long. Relief valve should take care of that issue. That is why they have max psi settings of 3000 and "not until it breaks." It does seem weird why 2 different areas both had problems. Defect in the hydraulic system or relief valve? It would be nice to measure what the hydraulic pressure is in the system on that unit.

The salesman made it sound like this is how all machines are made. "you just have to be careful"

I also called the service dept. and they guy I spoke with also supported the salesman's statement that you cannot keep the hyd. on for very long at all.

Perhaps there is a problem with a few of these newer machines?

 

[radman1]

Hopefully, another bobcat dealer/salesman will help answer this issue. I just can't believe they designed it that way. For example, if the toolcat was using a hydraulic PHD and the bit stopped/hit a rock, it would potentially cause a burst in the hydraulic system? Major design flaw if that was true. This doesn't happen with any skid steer on the market, including Bobcat. On my bobcat 873, I am frequently running the axillary hydraulics against stopped/nonmoveable loads on the attachments including trencher, tree spade, tree shear, 2 different grapples, PHD etc. Hydraulics do not burst or even threat of problem.
The distribution block mentioned earlier is present on most newer bobcat skid steers and are designed for 3000 psi. I believe there must be a problem on the relief valve of that toolcat or faulty distribution block. Standard flow or high flow setting should make no difference.

 

[radman1]

I just talked to my salesman/dealer. He said holding the auxillary hydraulics on is not an issue for the hydraulic system. Nothing should break/burst.
He has sold 2 D series units, no problems. Has had 3 more stock units on order for over 3 months but not yet arrived. Says they only units he can get at this time, are units that are already sold. Can't get units yet for stock. Sold units are given priority in the build process over in stock built units.

 

[jmfox]

Here's another problem related to axillary hydraulics and triggered by static pressure:

jmf

Hydraulic leak between two left wheels 743B
Posted: 01/09/2007 08:16 AM
Looks to be between pump and body, is this my auxillary pump? I have no repair manual does anyone have a parts break down of pump or bobcat? I Lent out my Bobcat to a friend and he applied lever in auxillary mode with no aux attachements and now i`m leaking fluid around pump on left side . I need help please

 

[dakota-2000]

I've moved logs and a lot of big rocks so far with the 4-way bucket. I clamped on to rocks hard like I did with the C with no problem. The big problem I'm having with my D is the cooling fan won't come on. I thought it the overheating was a air lock in the coolant but it wasn't.

The service man came out and diagnosed my problem as a faulty hydraulic motor on the fan. He ordered a new one and in the meantime I give the fan a poke with a screw driver each time to get it started. I will use it that way until he gets the new motor.

 

[jmfox]

Before taking delivery of a machine (along with kicking the tires) it would be a good idea to detach all hydraulic couplings and exercise the hydraulics, especially the auxiliary, to check for leaks. On my old Ford tractor I capped off two hoses until I can find a new top link, and now I'm wondering if this could be the cause of a new leak in the control block.

jmf

 

[White Shark]

Before taking delivery of a machine (along with kicking the tires) it would be a good idea to detach all hydraulic couplings and exercise the hydraulics, especially the auxiliary, to check for leaks. On my old Ford tractor I capped off two hoses until I can find a new top link, and now I'm wondering if this could be the cause of a new leak in the control block.

jmf

Good advice. When machines are new, they sometimes develop minor leaks too, that can be fixed with a twist or two of a wrench. I've had this happen on a CAT 304 excavator and a CAT skidsteer. No biggie. Each machine had less than 10 hours when the leaks started. I got the wrench out and they were fixed in minutes.

Having a hydraulic block die is another matter. Something is faulty or defective. Those things are designed to take punishment and plenty of high pressure. The Dealership guy needs to read the Service Bulletins or do some asking around since that is not normal...

.