Hydraulic Leak Around Filter-Gravely 148Z


LawnSite Member
Northcentral PA
Purchased a used Gravely 148z (2005) last winter, mowed with it all summer (did very well), and then during early fall, I noticed there was a leak developing around the hydraulic filter (see picture). It was VERY slow, but it would be enough to pool up a little puddle about 3" on the cardboard in between mowing sessions (1 week usually). The hydraulic reservoir still reads within normal range, but I'm sure after plenty of mowing, it would drop. Since I didn't mow with it much afterward, I've put off servicing this. Is there a replaceable seal (aside from the one on the filter), or is it likely coming from some other source? There are no breaks in the lines running in or out of the filter, but from the looks of it, it appears the leaks is coming from somewhere above the filter housing. My next step would be to consult the dealer (80 miles away), but I thought I would check here as well for part/general information. Thanks for any information you can provide.



LawnSite Senior Member
Wichita, KS
I have a Gravely walk-behind that has that same filter and mine was leaking as well. What I found was I could tighten the filter more as it appeared to me that it was just leaking from not being tight. I have yet to mow with it to see if it helped as I did it over this winter. But, I am doubting that it would be leaking from anywhere else on my mower. If you can see the filter while the mower is running you may try heating the hydraulics up and then jack the mower up on stands so the wheels can turn freely. Clean the area up and then see if you can see a drop accumulating.

You may be able to remove the filter and inspect the o-ring to make sure its not cracked or damaged in anyway. You would have to purchase a new filter to get a new o-ring and only your gravely dealer would have that filter as it is a special filter made specifically for them. I believe they're pretty expensive, north of $20, from the research I've done but I could be mistaken on that.

Good luck.