L48 no forward or reverse

[DMacBuilder]

Installed new front pump and clutch everything worked just fine after about 10 hours. I moved the machine and I stopped and then it wouldn't move again fel and backhoe work buy I have no forward or reverse I noticed I have a small leak now at the auxiliary pump top line and the backhoe /PTO handle for when the backhoe is removed has no resistance when you move it

 

[rbargeron]

Installed new front pump and clutch everything worked just fine after about 10 hours. I moved the machine and I stopped and then it wouldn't move again fel and backhoe work buy I have no forward or reverse I noticed I have a small leak now at the auxiliary pump top line and the backhoe /PTO handle for when the backhoe is removed has no resistance when you move it

Many HST problems start somewhere in the linkage on the outside. Aux pump is not involved in HST's function. Usually something under the right floor board isn't right. Hope this helps. Dick B.

 

[rScotty]

Installed new front pump and clutch everything worked just fine after about 10 hours. I moved the machine and I stopped and then it wouldn't move again fel and backhoe work buy I have no forward or reverse I noticed I have a small leak now at the auxiliary pump top line and the backhoe /PTO handle for when the backhoe is removed has no resistance when you move it

Many HST problems start somewhere in the linkage on the outside. Aux pump is not involved in HST's function. Usually something under the right floor board isn't right. Hope this helps. Dick B.

View attachment 807703

Nice illustration! When my HST F/R quit working it was an external control cable that had come undone.

BTW, did you mean the backhoe/3pt lever? On our M59 that lever never has had any resistance to movement. I'm not even sure why it stays in any location.
rScotty

 

[DMacBuilder]

Thank you guys yes I meant the backhoe PTO lever anyway I'm the original owner since new back in 2001, so I'm very familiar with the machine and all the linkage and how it works I do believe the hydrostatic works of pressure and I'm not sure how to check any of that I did see one cable underneath, but that went to the PTO lever I have the workshop service manual, and a parts diagram book and I have just enough knowledge to get myself in deep ****. I build homes for a living and I've done all the service to the machine shop mechanically inclined but when it comes to hydraulic flow and I'm lost. my son installed a new clutch for me and everything worked fine until like I said I moved maybe 50 feet no noise no nothing just wouldn't move again

 

[rScotty]

I'm wondering why the original clutch and pump work was done. And I'm confused about the ten hours. Did you do a lot of HST work in that ten hours or was that stationary? If it drove around OK for ten hours, then I'd figure the insides were good forever and be looking at the external control levers - like that PTO lever & cable.
Why would it have a lever for chosing between PTO and Backhoe? At first I thought it was a hydraulic motor driven PTO - but I don't see it on this diagram.
BTW, it is a PDF so I think it will download instead of display. If anyone knows how otherwise give it a go.

 

[DMacBuilder]

Most of that 10 hours was that backhoe work I change the pump because I did something wrong to it externally on the threads. The clutch needed to be replaced because in the winter while plowing, the machine did the same thing stop moving it was shot The machine is 20years old. So it definitely needed a new clutch. How do you test the pressure on the hydrostatic transmission?

 

[DMacBuilder]

Also win the backhoe is not on the machine. The lines are not connected so you have to move the lever. I would assume to divert the flow, so it doesn't deadhead at the end of the line.

 

[rbargeron]

There's a discussion about similar symptoms here that might give you some ideas.

Did you replace the front-most pump (steering) or the one right behind it (main hydraulics)? Reason I ask is the HST's charge pump gets oil from the steering return line - if there's a loose fitting there or on the oil cooler the charge pump may be sucking air and not supplying the regulator - so no shifting.

 

[rScotty]

There's a discussion about similar symptoms here that might give you some ideas.

Did you replace the front-most pump (steering) or the one right behind it (main hydraulics)? Reason I ask is the HST's charge pump gets oil from the steering return line - if there's a loose fitting there or on the oil cooler the charge pump may be sucking air and not supplying the regulator - so no shifting.
View attachment 807822View attachment 807825

Yes, I agree with that. I remember back at the start the OP said there is a slight leak at an upper connection. So we should talk a bit about suction leaks. A suction leak will put enough air into the system to prevent the HST from working, but will not leak visible oil out until the engine is turned OFF. The reason for that is that with the engine off, the pump is not sucking air into the line and that means that any oil that is sitting in the line or up in the pump is free to slowly leak out.

BTW, looking for an oil wetness that doesn't happen unless the engine is not running is a good way - an old mechanical trick - to look for suction leaks that you just cannot find any other way. First wash it down in that area with soapy pressure washer to get the old oil off and then you can tell by seeing new shiny clean oil after you run it. Or another way is to simply replace all suction lines and tighten suction joints. Particularly be sure to replace all 20 year old rubber suction hoses even if they look good - and especially if they are the kind held on with worm drive clamps - they leak at the ends where you can't see the split.

I cannot emphasize to strongly how often a suction (air) leak between the hydraulic filter and the pump is what is causing a hydraulic problem.

Here are views of the PDFs I posted yesterday.
rScotty

 

[rbargeron]

Does your steering still operate easily and smoothly left-to-right-to left with the tractor running but not moving? If its jerky the front-most pump may have a suction leak - which could make the hst stop shifting F - R. Check (tighten) the connections at the pump.