ARNAUDVILLE
Member
thanks I had the same problem .
Branson 4720H Whine
- Thread starter Eric1973
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Texasmark
Elite Member
- Joined
- Apr 24, 2012
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- 3,703
- Location
- N. Texas
- Tractor
- Ford: '88 3910 Series II, '80 3600, '65 3000; '07 6530C Branson with FEL, 2020 LS MT225S. Case-IH 395 and 895 with cab. All Diesels
I look for 2 specs for my tractors, not because I have a JD (which I had several and currently don't) but because if any spec is posted, J 20C shows up for the premium fluid required in today's tractors, and JD 303 shows up for the yesteryear tractors like my Fords.
The whine in hydraulics usually is little bubbles in the fluid cause by a compression of some sort in the line changing the flow from "laminar" to restricted/released, causing "turbulent" flow where the release is essentially a vacuum "pulling the oil apart" sorta thing.
The hotter the fluid the more volatile and the easier it is to "pull it apart". The hydraulic circuit is a closed loop and the pump is pumping on the one hand and sucking on the other....source of the vacuum. It's kind of like boiling water. At one atmosphere it boils at 212F but if you pull a vacuum on the container you can get it to boil at a much lower temperature. Not a hydraulics expert but that's how I see it.
The whine in hydraulics usually is little bubbles in the fluid cause by a compression of some sort in the line changing the flow from "laminar" to restricted/released, causing "turbulent" flow where the release is essentially a vacuum "pulling the oil apart" sorta thing.
The hotter the fluid the more volatile and the easier it is to "pull it apart". The hydraulic circuit is a closed loop and the pump is pumping on the one hand and sucking on the other....source of the vacuum. It's kind of like boiling water. At one atmosphere it boils at 212F but if you pull a vacuum on the container you can get it to boil at a much lower temperature. Not a hydraulics expert but that's how I see it.