New Holland L35 Hydrostat Question

[carbineone]

Hey everybody,new here so greetings to all of you.. I have a older L35 and heres whats going on with it..The drives work perfectly on both sides when going forward but the when trying to back up the machine the right side will not work in backwards operation..As sated the machine operates perfectly going forward though...There are no strange noises,the right side trys a little bit in reverse but just moves very slightly,left side works great in reverse however..I would think if the machine works perfectly going forward that this has to be something minor making the reverse not work on one side..Thanks and please help me out if you can....Bruce

 

[Mike10]

There is a forward and reverse relief valve for each side. They are in the center section, backplate, between each pump and motor. You can try switching them to see if the problem reverses. There are also check valves in this center section, backplate. One of them could be bad and not allow pressure to build in reverse. You can go to newholland.com and look up the location of the parts in the parts section of the website. Look for the Cessna backplate.

 

[carbineone]

There is a forward and reverse relief valve for each side. They are in the center section, backplate, between each pump and motor. You can try switching them to see if the problem reverses. There are also check valves in this center section, backplate. One of them could be bad and not allow pressure to build in reverse. You can go to newholland.com and look up the location of the parts in the parts section of the website. Look for the Cessna backplate.

Well heres what I tried,theres two big nuts on the top and the bottom of the right hand block.I removed them and switched the top valve to the bottom port and vise versa and still the same thing..Theres also a small valve on top next to the big one..It has a check of some kind in the small one and my question about that small one is should you be able to just blow through it from both directions with little resistance? Maybe thats the culprit..Also could a valve on the left hand block side cause the right reverse to not work..Never switched any valves from the left side to the right as I just assume the problem is in the right block exclusevly. One other thing could the squash plate or whatever its called that moves the rotating group have a pin sheared inside that may cause the plate to not fully rotate to reverse? But you would think it would kick in occasionally by jocking the handle around..Thanks

 

[Mike10]

Well heres what I tried,theres two big nuts on the top and the bottom of the right hand block.I removed them and switched the top valve to the bottom port and vise versa and still the same thing..Theres also a small valve on top next to the big one..It has a check of some kind in the small one and my question about that small one is should you be able to just blow through it from both directions with little resistance? Maybe thats the culprit..Also could a valve on the left hand block side cause the right reverse to not work..Never switched any valves from the left side to the right as I just assume the problem is in the right block exclusevly. One other thing could the squash plate or whatever its called that moves the rotating group have a pin sheared inside that may cause the plate to not fully rotate to reverse? But you would think it would kick in occasionally by jocking the handle around..Thanks

Check valves are item 6. It has been awhile since I had one apart, but I think there is a ball in each valve and a pin to hold the ball in valve cylinder. The valves are held in place by orings, so all you need to do is grab them with a pliers and pull them out. It looks like you will need to remove item 8 to get to them. If the balls do not seat or are missing you will loose pressure in one or both directions. Item 13 are the relief valves. No need to switch relief valves from the left side to the right side. One side does not affect the other side.

 

[carbineone]

Check valves are item 6. It has been awhile since I had one apart, but I think there is a ball in each valve and a pin to hold the ball in valve cylinder. The valves are held in place by orings, so all you need to do is grab them with a pliers and pull them out. It looks like you will need to remove item 8 to get to them. If the balls do not seat or are missing you will loose pressure in one or both directions. Item 13 are the relief valves. No need to switch relief valves from the left side to the right side. One side does not affect the other side.

Thanks for the diagram,I found that one on the New Holland site you told me and this one in the pic looks like a differant setup than whats in my New Holland,,The pumps in mine have the relief valves that go in the top and the bottom not in sideways like these..The pumps are also mounted in the loader sideways if that helps..They are not in a front to rear setup like in the Bobcats you see..Unusual setup for sure...I will however see if theres one of those covers on the bottom side of the block as shown and see if I can find these check valves..

 

[Mike10]

Thanks for the diagram,I found that one on the New Holland site you told me and this one in the pic looks like a differant setup than whats in my New Holland,,The pumps in mine have the relief valves that go in the top and the bottom not in sideways like these..The pumps are also mounted in the loader sideways if that helps..They are not in a front to rear setup like in the Bobcats you see..Unusual setup for sure...I will however see if theres one of those covers on the bottom side of the block as shown and see if I can find these check valves..

The picture is oriented that way but in the loader the backplate is rotated 90 degrees so the valves are on top and bottom. Just rotate the picture 90 degrees. The only other setup you might have is if you have Vickers hydrastats. The Vickers used hydraulic servo controls for the steering linkage. If you have hydraulic lines going to your steering control linkage than you have Vickers transmissions.if not you have Cessna.

 

[carbineone]

The picture is oriented that way but in the loader the backplate is rotated 90 degrees so the valves are on top and bottom. Just rotate the picture 90 degrees. The only other setup you might have is if you have Vickers hydrastats. The Vickers used hydraulic servo controls for the steering linkage. If you have hydraulic lines going to your steering control linkage than you have Vickers transmissions.if not you have Cessna.

Yes there are lines going to the steering linkages..Probably vickers then? Hope I can figure this out its getting frustrating and I cannot afford to pay anyone to fix it...Thanks

 

[cnord]

Yes there are lines going to the steering linkages..Probably vickers then? Hope I can figure this out its getting frustrating and I cannot afford to pay anyone to fix it...Thanks

Look on the mounting ear or look for a tag and see if you can get us a part number. That might help, or if you can take some pictures.

 

[carbineone]

Look on the mounting ear or look for a tag and see if you can get us a part number. That might help, or if you can take some pictures.

I will take a pic and post it asap...Thanks