1. Assuming you moved the unit w/o bypassing hyd. you likely blew the pump shaft seal at the time of your initial repair. There should be (or sometimes is) a lever to allow the fluid to go back to tank for freewheeling. Relief should have saved it, but it could have been mal-adjusted from go. I bet it was hard to push until it went over relief?

1. Relief started to weep a little for an undeterminded reason- as hydro sytems age, things start to weep. Weeping isn't a symptom of bypass- once the relief opens, it just goes back to tank. In fact, you ever stall the hydraulics going up a hill or through a ditch? Makes a whining noise with no movement? That's going over relief.

2. When you tighetened the relief, you raised the pressure that it takes to open it. Could be a big adjustment- it's a spring that opens up a poppet under pressure- let's say it was set at 2000 psi, quarter turn could have raised it to 2500 psi. Now you would have less protection on the system.

3. Either the pump seal decided to let go at the time of the initial repair, or the pushing it over relief caused it, sounds like the shaft seal failed first (obvious, right?) but the metal noise means pump failure, or worse- you cooked both pumps, the other pump, or one or both of the drive motors beacuse of a lack of oil (we don't know where). Remember, the oil on that system is not closed loop it's just normal (meaning both pumps share a common reservoir). So, yeah, you may have a catastrophically leaking shaft seal, but you may have killed the other pump, one or both of the motors, or the pump you are diagnosing because of oil starvation due to seal failure at the leaky pump.

Take it to the dealer. Piston components aren't to be trifled with.

ETA- read your last post. Rotating group on the pump or shaft bearing/bushing sounds like it's shot. You are probably in the right direction, but no guarantees something else didn't die in the process- i.e. motor seals are good, but the rotating group is scarred, causing internal leakage and loss of performance.

Make sure you get a 2 new filters if you DIY- this stuff NEEDS MUST HAS TO BE clean. You need to run it, and then change the filter again.

This post was edited on 9/5/16 at 6:29 pm

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Posted by Bama323_15

Member since Jan 2013

2100 posts

Posted on 9/5/16 at 6:33 pm to subMOA

quote:
. Assuming you moved the unit w/o bypassing hyd. you likely blew the pump shaft seal at the time of your initial repair. There should be (or sometimes is) a lever to allow the fluid to go back to tank for freewheeling. Relief should have saved it, but it could have been mal-adjusted from go. I bet it was hard to push until it went over relief?

This initial movement was made while under power. I did not make that clear in my original post.

quote:
2. When you tighetened the relief, you raised the pressure that it takes to open it. Could be a big adjustment- it's a spring that opens up a poppet under pressure- let's say it was set at 2000 psi, quarter turn could have raised it to 2500 psi. Now you would have less protection on the system.

Yep, this was what I was guessing happened in general. However, since hydraulic systems are new to me I was not 100% certain.

quote:
3. Either the pump seal decided to let go at the time of the initial repair, or the pushing it over relief caused it, sounds like the shaft seal failed first (obvious, right?) but the metal noise means pump failure, or worse- you cooked both pumps, the other pump, or one or both of the drive motors beacuse of a lack of oil (we don't know where). Remember, the oil on that system is not closed loop (meaning both pumps share a common reservoir). So, yeah, you may have a catastrophically leaking shaft seal, but you may have killed the other pump, one or both of the motors, or the pump you are diagnosing because of oil starvation due to seal failure at the leaky pump.

I really had not considered that possibility until you mentioned it.

Currently I am planning on ordering a completely new pump and was planning on talking with a technician to make sure the relief mechanism comes pre set on a new pump as I don't want to attempt to set it.

Also found a video of the exact model pump I have. This guy is doing a complete rebuild on the pump.

Pump Rebuild

Definitely looks like something that I will attempt with the old pump at some point.

Thanks for the advice.
(I am stubborn enough to always think I can figure this stuff out eventually. Most of the time it works out. Sometimes I end up costing myself extra time and money.)

ETA: You added-

ETA- read your last post. Rotating group on the pump or shaft bearing/bushing sounds like it's shot. You are probably in the right direction, but no guarantees something else didn't die in the process- i.e. motor seals are good, but the rotating group is scarred, causing internal leakage and loss of performance. Make sure you get a 2 new filters if you DIY- this stuff NEEDS MUST HAS TO BE clean. You need to run it, and then change the filter again.
This post was edited on 9/5 at 6:29 pm

Thanks. Will do. Was also going to research how to do system flush.

This post was edited on 9/5/16 at 6:39 pm

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