Suction manifold hose collapsing

[harpo]

I have a JD 4300. The hydraulic suction hose above the steering/hydraulic pump collapses when I start the tractor. I have changed the fluid & filter and cleaned the pre-filter above the pto shaft, but I still have the same problem. The old fluid was very cloudy, opaque. I took the suction hose off to inspect for cracks, but appears to be OK. The hydraulics are sluggish and jumpy as well as the steering.
Has anyone else experienced this problem or have an idea what the cause might be?

 

[RogerH]

The 4310 has a coiled spring that slips inside the suction manifold to prevent collapse. You might want to order one for your 4300. Also, did you clean the transmission screen when you changed the oil? I have seen those get stopped up with gunk, particularly when there is water in the oil. If your tractor sits outside, you may also want to change the oil fill cap on the rear to the newer style that was used on the 4310 (and I think is still used on the 3000 series).

 

[harpo]

Roger, thanks, I'll order the spring. I can't locate my manual, where is the transmission screen located? My tractor does sit outside. You think water may be leaking past the cap? I'll order the 4310 cap also. Thanks.

 

[harpo]

Found the tranny screen and cleaned it. Fixed the problem with the suction hose. Thanks. - A side question- Do you check tranny fluid level with engine running or off?

 

[RogerH]

Glad that cleaning the screen seems to have fixed your problem. Perhaps the spring won't be required.

I would suggest checking the oil level with the engine off. When it is running the churning of the oil makes it difficult to use the sight glass. Just be sure to recheck the oil after adding an attachment that uses hydraulics (cycle it a few times first, then check the oil). Sometimes oil will have drained or leaked out of the cylinders of attachments, then the tractor has to make that up.

John Deere made a running change to the fill cap and I seem to recall seeing a service bulletin that suggested that the change was made due to water getting in around the cap. I never liked the fit of the threads on the older style cap. The new one seems to fit better.

 

[Bdawg22]

The 4310 has a coiled spring that slips inside the suction manifold to prevent collapse. You might want to order one for your 4300. Also, did you clean the transmission screen when you changed the oil? I have seen those get stopped up with gunk, particularly when there is water in the oil. If your tractor sits outside, you may also want to change the oil fill cap on the rear to the newer style that was used on the 4310 (and I think is still used on the 3000 series).

Roger are you saying that there is supposed to be a coiled spring inside the F shaped manifold that sits on top of the hydraulic pumps?

 

[beenthere]

Bdawg22
Might send RogerH a PM as his post was 19 years ago. Or post what your situation is now that may be a problem you are trying to address.
Hope the 4310 is running good for you.

 

[kennyd]

Roger are you saying that there is supposed to be a coiled spring inside the F shaped manifold that sits on top of the hydraulic pumps?

Wow...old thread!!!!!!

But, yes, here is the parts diagram. Those rubber manifolds are well known for cracking and allowing the pumps to suck air, causing cavitation. They are cheap to replace.

https://partscatalog.deere.com/jdrc/sidebyside/equipment/4044/referrer/navigation/pgId/2821176