Rebuilding a hydraulic pump from a JCB 506c loadall

[Ricothebear]

Hey everyone, so I decided to get my hands dirty again and have a go at fixing a leaking hydraulic pump in a JCB telehandler. It was leaking about a drip every minute, so It was pretty bad. The foreman who was using it said it had been leaking like that for a month. but it only leaked when you shut it off (makes sense because the vacuum created by the pump kept the oil from leaking during use. Then he would park it over a drip pan and turn it off).

I've never done this before but I have worked on automotive transmissions in the past, so I figured this would be the same principle. Pull pump, disassemble, inspect, replace seals (best case) Replace pump (worst case)

I drained the units hydraulic tank and pulled the pump off already. I'm going to disassemble it tomorrow but I wanted to be sure I'm not getting ahead of myself here. So I thought I'd ask here first:

1. Is there any visual indicators that the current pump is garbage
2. Would you bother replacing seals (is it worth the risk of having it leak again) or just get a new pump (cost of JCB seal kit is 70$ , cost of new pump is 950$)
3. What is typically the cause of the pump seal failing?
4. any other advice or suggestions for a first timer here?

 

[f311fr1]

Pictures would help. You can probably replace as cheap as you can repair. What type of pump is it? Gear, Vane, or Piston? If it is a gear you should be able to reverse eng a replacement.

 

[Ricothebear]

Here is the pump, It is a two gear style. I've got it disassembled, the bearings look ok, no scoring or discoloration, gears look ok to me. The leak was coming from the lip seal for sure. I don't have a shop press so I'll have to go get the flange pressed off the shaft sometime to change out the seal. I'm going to call around to JCB dealers and try to get ahold of the seal kit. I got a P/N off their website, hopefully they still make the kit
.

 

[Ricothebear]

So I had my neighbor press the shaft out. Boy, that was in there tight. Scared the **** out of both of us when it popped haha.
The seal was the culprit, it was torn a bit . Funny thing is I think the seal was installed inside out......I may be wrong, but it's a double lip seal and the side that is more open was facing the outside. I always thought the side with more "face" should face out. There is springs on both sides.
Anyways, I hope i'm doing this correctly........we will see I guess.

 

[Ricothebear]

Cleaned it all up, still waiting on weather or not I can get a seal kit.

 

[Ricothebear]

OK bingo, found a seal kit. 100$ Shipped
Local JCB distributor wanted 280$ plus 50$ shipping.........Why is everything so expensive locally?
I got a quote to rebuild the pump earlier from a local hydraulics shop, was over 1200$
Found a local guy who could get me a new pump for 1200$
Went online and found a guy in US who would sell for 800$ shipped
These are all in CAD prices(I did the conversion)

I don't understand

 

[f311fr1]

JCB bought the pump and marked it up to the dealer, who marked it up to you. The guy who sells the pump direct to yo has one less link (markup) in the chain.

 

[Ricothebear]

Makes sense. I understand it too I guess, people providing services gotta get paid.
I used to work for a transmission parts distributor when I was young. We would sell seals anywhere from 0.50 to 7.00 each. After working in a tranny shop years later and seeing the shop charging the customer $40.00 for a $7.00 seal....I was pretty shocked. I'm in the construction industry now. Same thing I guess.

 

[Ricothebear]

Seal kit came in today, Got the case and seal in the freezer right now, probably going to assemble tomorrow. We will see if the freezer trick works. I'm still hoping I was correct in determining that the installed seal was backwards, the U face was facing outwards. I do not know who replaced the seal last time, but I do hope I am correct.

 

[Ricothebear]

Ok so I installed the shaft seal, and replaced all the other seals as well, I didn't have a torque spec on the "clamping bolts" (is what I understand they are called) so I torqued them to 45 ft lbs. The shaft nut with woodruff key I tightened to 100 ft lbs.
I bolted it all back together and replaced the hose clamps on the inlet side because I noticed some were in rough shape and wouldn't tighten properly.
I Filled it back up with hydraulic fluid.
I started it up and all was well. I slowly moved the boom in and out, up and down, drove around a bit. Parked it and checked it a while later, so far no leaks.
This was much easier than I expected, and I learned quite a bit. I do enjoy wrenching on heavy equipment, that's for sure.