420c motor problems or something else???

[JD Tim]

I was looking a buying a 420c and went to get it running today and it ran fine for about 5 minutes and then it started making a metal to metal screeching sound and bogged the motor and stalled out. Yes it has oil in it(with oil pressure in the normal range.) and all the other obvious things to. We refired it and it runs fine for 15 seconds(with no noise) or so and then does the same thing. Took the plugs out and it turns over freely. It has a dozer blade on it so could this have anything to do with the hydraulic pump seizing up? Also what would this be worth in this condition(everything looks to be in better than average shape.) What do you guys think?

[redkneckracer]

yeah that sounds like your hydro pump is cavitating.try lifting your blade as soon as you start her and see if it stals your engine at idle. she should lift her blade no sweat at idle. and if you can't pin point the scraping sound id try running her with the clutch disengaged first to make sure its an engine problem and not your transmission going to peices. if she got good undercarrage and good finals she still worth $2000 or $3000 in my oppinion.

[JD Tim]

Tried it with the clutch in and out, trans in neutral, there is no reverser, no difference, same problem. Thanks for the reply! If anyone else has any ideas let me know.

[H-D]

I wonder if there might be enough water in the hydraulic fluid to block the suction screen? That should cause a similar racket to what you report. It would cause a cavitation issue as redneckracer opines as well. I'd try to warm the old girl up before getting too bent.

[Ray III]

If it is below freezing where you are, and water has gotten into the hydraulic system, it can cause problems like this.

[Willyr]

LOL dumb question? What happens when you loosen your generator / alternator?