Robert,
Cat will play fair on your core charge.
I stripped my failed D8R pump out of curiosity and it wasn't too bad.
I got about 1500 back if I recall
I was thinking about stripping the core myself just to see if it's totally broken then see what they refund.
So I finally got time to work on the dozer. The hoses took 1 hour to get off, the trans pump took 20 minutes (2 bolts), the implement pump has 4 bolts. I took 3 off in 10 minutes then fought for literally 5 hours on the bottom bolt. The housing was in the way. I made 3 trips to a store for different tools until I finally realized I needed a swivel ratchet wrench. Once I got that I had it off in 20 minutes. Total tear down about 7 hours with the 5 hour hell learning curve.
Put implement pump on in 10 minutes, all bolts on in 10 minutes, forgot to hand tighten one bolt and it got stuck against the pump frame so took bolts back off a little to hand tighten that last bolt and tighten with wrench. Add another 15 min. Trans pump was a breeze, 10 mins to install and tighten bolts. About 45 minutes to install.
I asked cat for all seals including o-rings for hoses. They said it was all there but they forgot the o-rings. So I'm going tomorrow morning to get the o-rings and expect 1-1.5 hours to put hoses back on. So total install will be about 2.5 hours. If I needed to take the whole thing apart again I bet I could do it in 3 hours. Even with my 5 hour wrong tool mistake, a guy (me) with no mechanic experience on heavy equipment did it in less 10 hours without the right tools, 1/6 the 60 hours Cat said they would need. Adds to my mistrust of Cat. That along with them trying to charge 8 hours for the diagnostic.. then I said hey you called me at 9:30am and said it's done so why 8 hours? Then they responded saying oops you really owe 4 hours, our bad. Mhmm... Oh and they were also going to charge 20 hours to clean all hoses.. but also had all new hoses on their parts list, which hoses are custom built and non refundable so I said I'll get if needed, but still they said they were going to charge 10 hours to clean hoses.. new hoses.. very dubious.
Now for the dirty hydraulic tank. All hoses are clean but I cleaned them anyway with water and rags then let dry. Took 30 minutes since hoses were already off and only had 3 hoses connected to the tank. I tore down the entire fender around the tank and opened the tank, used a electric gun so that whole process took 10 minutes. There was about 3 hand fulls of dirt and rocks inside the tank. Good thing the tank sucks oil from the middle. Covered the intake, took a hose and blasted everything out then wiped with non lint towels. 15 minutes.
So cats 20 hour quote to tear down and clean took me 1 hour. Granted I didn't hook up a bladder and run everything to clean out any oil in the hydraulic pistons but since none of the hoses had any dirt in them even with the tank having dirt, I'll probably either change the hydraulic oil once or twice very quickly OR disconnect the return lines from the blade and ripper and let it spit out that old oil. Either way it will be taken care of quickly.
The whole process was very simple. It was hands on with heavy stuff but simple. Tomorrow is the big test to see if the pump was really bad or if it's a stuck valve. I'm still very skeptical of Cats diagnosis for two reasons, one they said they cut the hydraulic filter open and it was full of dirt and metal. Reason for skepticism is they didn't cut it open, and when I cut it open it contained no dirt or metal. Then two, they said they removed the line in the picture below and that's the k screen test which should give 1.5 gallons of oil at full rev and stall however mine gave 5 gallons in 10 seconds at idle. From what I just experienced with those hoses and oil, I find it hard to believe the one tech working by himself was able to disconnect a hose while holding a 5 gallon bucket way down there then turning the machine on from up top without spilling a little oil..then on top of that if they took out 5 gallons like they said the tank should have been 5 gallons lower but it was totally full. But then again they do have OSHA on their arse for any drop so maybe he did do it clean, but doesn't explain the filter not being cut or having dirt/metal and also why the hydraulic tank was full when they said they removed AND wasted 5 gallons. Tomorrow will tell if they really did a correct diagnosis