BH77 backhoe swing problems.

mmhulan · Mar 16, 2025

I am having a problem for some time now with my Kubota BH77 backhoe. The swing from side to side is losing power and stopping and starting. I can swing the boom from side to side free hand by holding the stick hard over and it moves freely. Ive done a lot of testing and it seems like it maybe pressure release problem. The control valve for the swing has two control release valves. One on top and one on the bottom. Im confused as to what each one does and which one releases for what each function. Has anyone experienced this type of problem. Thanks

rScotty · Mar 16, 2025

mmhulan said:
I am having a problem for some time now with my Kubota BH77 backhoe. The swing from side to side is losing power and stopping and starting. I can swing the boom from side to side free hand by holding the stick hard over and it moves freely. Ive done a lot of testing and it seems like it maybe pressure release problem. The control valve for the swing has two control release valves. One on top and one on the bottom. Im confused as to what each one does and which one releases for what each function. Has anyone experienced this type of problem. Thanks

There has been quite a bit written about irratic swing problems in backhoes. In Kubotas it seems to be a relief valve or check valve problem in the backhoe control valve assembly more often than not. Nobody seems to know for sure, but some believe the proble is a piece of crud gets caught on the valve face.

The relief valves have a lot of small parts to keep in order, but are simple to take apart and clean. That has worked for several people on TBN. I can't point to the specific thread, but recall several threads on that.

I couldn't have figured out our Kubota M59 TBL without the shop manual. The TBL series Kubotas use the TB series hoes, and their shop manuals go into a lot of detail about what each relief valve does with photos and illustrations of flow. It is surprising how different each hoe is, though. Is there a shop manual for the BH77 series hoes?

rScotty

jfsawatzky · Mar 16, 2025

I should have a wsm for my bh76 but I don’t recall if its for that specific model… I don’t think I could find one for the bh76 when I was looking so I bought the closet I could find. I’ll attach a photo/s when I have a chance