Export thread

JD 425 mystery oil leak

#1

Deere1329

Deere1329

I have upgraded from my GT235 to a 425 because it was a deal that was just to good to pass up. It only has 610 hours on it and needed a fuel pump and the fenders and hood were pretty busted up. But for $325 it didn't matter to me. Once I replaced the fuel pump and cleaned up the carb she fired up immediately and runs great. The only outstanding issue is the oil leak. After sitting overnight I see 2 small oil spots on the floor near the front of the deck (where the roller is). I have read that the valve covers are usually the culprit, however I am not really seeing any leaks there. Any one with a 425 have any advice? Also anyone have a PDF of the tech manual for a 425 that they would be willing to share with me? All help is appreciated. Thanks in advance.


#2

StarTech

StarTech

Install about 1/2 oz of oil uv dye, engine engine 5-10 minutes, and scan with uv dye leak detection light. Should make finding a lot easier than guessing.


#3

Deere1329

Deere1329

Install about 1/2 oz of oil uv dye, engine engine 5-10 minutes, and scan with uv dye leak detection light. Should make finding a lot easier than guessing.
Thanks for the advice I will look into that and a few cans of part cleaner to get the oil build up off of everything :)


#4

JoeM(GA)

JoeM(GA)

valve covers did tend to leak, along with dipstick tube o-rings and with age the oil pan end crank seal as there is no true crank bearing. They ride on a machined taper in the cast aluminum oil pan and it can wear.

message me your email, I can help you out with the PDF


#5

StarTech

StarTech

They ride on a machined taper in the cast aluminum oil pan and it can wear.
Hmmm, When did the Kawasaki started using tapered main crank journals on the FD620D? As far as I know they straight line bored. And the crankshaft only has a taper for the flywheel.

Any way once the engine exterior is cleaned the UV dye will pin point the leaky area. Just this week I found the two leaks on a Husqvarna rider has been in the dealer three times for oil leaks and they couldn't find the leak which stood out like sore thumb with the dye.


#6

Scrubcadet10

Scrubcadet10

This have the FD620 Kawasaki?


#7

StarTech

StarTech

Yes the JD 425 came with several versions of the FD620D. It also came with a diesel engine.


#8

Deere1329

Deere1329

Thanks everyone for the advice. I put in an order today for some uv dye, light and glasses kit. Fingers crossed!


#9

Hammermechanicman

Hammermechanicman

425 carburetor. 445 fuel injected. 455 diesel. If the gas engine made before 1998 may still have plastic cam. Around 800 to 1000 hours it will let go. Rebuilt a few of them.


Top