345 D Hydraulic Problem

strum456 · Oct 25, 2016

I have an intermittent problem with the internal hydraulics on my 345d. When on a a tilt (usually with the back of the machine facing down hill), there is a total loss of hydraulic pressure (no remotes, no PTO, no hydraulic lift). This doesn't happen often, but tonight it was pretty inconvenient when I had to remove the backhoe just so I could get the tractor onto level ground.

Conventional thinking would say that the fluid is low. According to the dipstick that screws into the top of the transmission, it is fine. I have never been able to find any other check or fill holes on the machine or in the manual, so I assume everything is filled through the top of the transmission.

If oil level isn't the problem, then maybe it is a pickup tube problem??? The hydraulics are strong and fast all other times. It is all or nothing.

TractorTech · Oct 25, 2016

Strum, the rear axle/hydraulic oil is separate from the transmission. There should be a dipstick on the LH side top of the rear axle facing back to be able to check from the back. The fill is through either of the large plugs on the top rear of the rear axle.

strum456 · Oct 26, 2016

Thanks for the info. Are you aware of a parts breakdown that shows this dipstick and fill plug? I have checked and checked.... I've been all over the tractor too. I really don't think mine has a dipstick where you are describing. It is an industrial model. 4x4 with a cab. The transmission is an 8x8 electric power shuttle.

aircommuter · Oct 26, 2016

Where is the hydraulic pump located?

TractorTech · Oct 26, 2016

I tried to include a picture from the parts book, BUT, it doesn't show any reference and TBN is being buggy about loading it. In short, it is item 52 and 53 at URL:Official New Holland Online Parts Store and Online Parts Catalog for New Holland and Ford Tractors.. If TBN blocked the URL, then go to a Messicks.com, New Holland Ag parts, 345D, Hydraulic System, Flow Control Piping, 53-Dipstick.
52 and 53, tube/dipstick go into the rear axle housing, LH side, into the hydraulic filter housing, I believe, on the 8X8 transmission equipped units. Otherwise, it goes into a blank plate with 4 holes on the rear axle center housing.

TractorTech · Oct 26, 2016

Aircommuter, on the 8X8 transmission equipped tractors, it has the pump in the RH rear axle center housing. On 4X4 models, it is located on the LH side of the engine block, rear.

TractorTech · Oct 26, 2016

Strum, since it has a cab on it, it should have the deluxe remotes on the back. The oil fill, because of the cab, should be through a tube with a cap on it that comes out of the rear axle behind the cab. The parts book doesn't show it, but it is the same or similar to that on a 4630 ag. tractor.

aircommuter · Oct 26, 2016

The reason I was wondering is he mentioned backhoe, usually the loader and the backhoe do not use the rear axle oil supply. They often have a front crankshaft mounted pump which gets oil from a tank in front of the radiator. i am familiar with the both the left rear engine mounted pump made by Sunstrand, and the internal axle housing pump but neither supply the volume required for a backhoe.

TractorTech · Oct 26, 2016

aircommuter said:
The reason I was wondering is he mentioned backhoe, usually the loader and the backhoe do not use the rear axle oil supply. They often have a front crankshaft mounted pump which gets oil from a tank in front of the radiator. i am familiar with the both the left rear engine mounted pump made by Sunstrand, and the internal axle housing pump but neither supply the volume required for a backhoe.

I see why you asked about the pump. I was focused on the problem of no 3pt, PTO or remotes, which as you know, operates off the rear sump and the backhoe would/should operate off of the front pump loader hydraulics.

strum456 · Oct 26, 2016

TractorTech said:
Strum, since it has a cab on it, it should have the deluxe remotes on the back. The oil fill, because of the cab, should be through a tube with a cap on it that comes out of the rear axle behind the cab. The parts book doesn't show it, but it is the same or similar to that on a 4630 ag. tractor.

I found the dipstick...it is me. Now I just need to figure out where to put the oil in the tractor (LOL). I'll let you know how it goes tonight.

Thank you so much for saving me big $$$ repairs. Do you know if the hydraulic pickup is down in a sump? I'm wondering if I now have to worry about damage done to my gears / bearings or if the oil level would have been adequate to provide lubrication.

I think I know why the oil would be low. Last winter we notcied that the 3 point was jerking. After some investigation, I found that the filter gasket was leaking. Something hit the filter, denting it and causing it to come loose. I put on a new filter, checked the TRANSMISSION oil (whcih of course was fine), and we've maybe put 30 hours on the tractor since. Most of that time would have been random loader work (not continuous) with the tractor in 4x4 and some backhoe work (tractor stationary). This tractor spends a lot of time idling while we hook up chains to whatever we are going to move or as we work from inside the bucket. Hopefully I didn't ruin the whole rear end!