Another power steering (HSU) leakage problem

[MArvane]

I have a '93 early model 4500 with a whopping 160 hours. Last weekend it started squirting PS fluid from the top of the steering column. I purchased the manual and started the procedures to remove the hydrostatic steering unit. My first problem is that I can not manage to remove a connection next to a piece of tubing that is apparently welded or brazed into the HSU (see photos 1 and 2). The quarters are so cramped that I can't get sufficient swing radius for a wrench. I took a 7/8" box wrench and cut open the end to go around the tubing but the clearance between the fitting and the tubing next to it is so close that the wrench won't go on. A standard wrench is too thick/stubby to get in at anything other than an angle too short to turn the fitting. Any suggestions as to how to remove this connection would be appreciated.

My second problem starts after I figure out the first. At this point the manual simply states to remove the four bolts that hold the HSU bracket down and remove the entire unit. The problem I see is that the two forward mounting bolts are under the fuel tank with insufficient clearance for access and removal (see photo 3). It appears that even if the fuel tank were loosened and lifted it would hit the tractor body within a fraction of an inch, not rising enough to allow removal of the bolts. I'm hoping that there is sufficient clearance to remove the HSU from the bracket out the side, but that even looks very, very difficult.

Does anyone have any experience in this HSU removal operation? Your comments and suggestions are appreciated. I can't believe how user-unfriendly this design is, but I'm sure it went together easily.

 

[bindian]

I have a '93 early model 4500 with a whopping 160 hours. Last weekend it started squirting PS fluid from the top of the steering column. I purchased the manual and started the procedures to remove the hydrostatic steering unit. My first problem is that I can not manage to remove a connection next to a piece of tubing that is apparently welded or brazed into the HSU (see photos 1 and 2). The quarters are so cramped that I can't get sufficient swing radius for a wrench. I took a 7/8" box wrench and cut open the end to go around the tubing but the clearance between the fitting and the tubing next to it is so close that the wrench won't go on. A standard wrench is too thick/stubby to get in at anything other than an angle too short to turn the fitting. Any suggestions as to how to remove this connection would be appreciated.

My second problem starts after I figure out the first. At this point the manual simply states to remove the four bolts that hold the HSU bracket down and remove the entire unit. The problem I see is that the two forward mounting bolts are under the fuel tank with insufficient clearance for access and removal (see photo 3). It appears that even if the fuel tank were loosened and lifted it would hit the tractor body within a fraction of an inch, not rising enough to allow removal of the bolts. I'm hoping that there is sufficient clearance to remove the HSU from the bracket out the side, but that even looks very, very difficult.

Does anyone have any experience in this HSU removal operation? Your comments and suggestions are appreciated. I can't believe how user-unfriendly this design is, but I'm sure it went together easily.

Looks like you need an offset angle wrench or a flared crows foot. The angle wrench has two different angles and are different angles than an open end or combination wrench. This wrench and an open end wrench should do the job. If not............a Bluepoint flared crows foot wrench (really a socket that can be used with a ratchet or breakover bar) from Snap On should be able to get in to do the job. Those bolts that lack clearance might just be an optical illusion until you get everything loose and try to remove them. Be careful prying any bolts out and back in as you may damage the threads enough to not start the bolt upon installation.
hugs, Brandi

 

[MArvane]

Thanks Brandi; I'll check it out. But first I'm going to try to find out if I need to take apart the entire tractor to get to this first. I just looked at a 5500 that was in the shop and M&M seems to have rectified the problem in subsequent units by relocating the interfering linkage, getting the front mounting bolts out from under the fuel tank, and raising the HSU enough to take it out without removing the entire bracket. Those small changes could have saved a lot of R&R time.

 

[bindian]

Thanks Brandi; I'll check it out. But first I'm going to try to find out if I need to take apart the entire tractor to get to this first. I just looked at a 5500 that was in the shop and M&M seems to have rectified the problem in subsequent units by relocating the interfering linkage, getting the front mounting bolts out from under the fuel tank, and raising the HSU enough to take it out without removing the entire bracket. Those small changes could have saved a lot of R&R time.

Leave it to an engineer:ashamed: to leave mechanical types:thumbsup: no easy way to fix stuff!
hugs, Brandi

 

[DJP]

HI: BINDIAN I have a Mahindra 4500 2wd, my HSU also started fluid leak coming from under the steering wheel, to later find out it was a leak in the top of the HSU. I took it to a repair shop, which they replaced the top seal. It also took me a long time getting out the HSU in my 4500 tractor model, which looks like the one MARVANCE has in his tractor. find the right set of tools to remove this HSU. Ok I got it removed and replaced back in my tractor. I checked and rechecked any leaks around the HSU, and the hoses that connect to the HSU, there was no leaks. But my problem is now that I did not have before I removed the HSU and had the seal replaced, after reinstalling the HSU, my steering will turn the front wheels a little to the left and a little to the right. I cannot make a sharp turn. the steering wheel will just go round and round while the tractor is moving and running, but the front tires turning very little. T turn my tractor around I have to make a large wide turn. Question is. 1. did the shop not set something in the HSU while replacing the seal that is not allowing me to make sharp turns<<< @. did I not sink in the steering wheel drive shaft correctly when reinstalling the steering wheel shaft on the HSU??? 3:is there maybe air in my steering lines. I jacked up the front wheels off the ground, with the engine not running and as I turn the steering wheel, the front wheels do not turn at all. Please give me some advice or what and how to check my steering issues.

 

[bindian]

HI: BINDIAN I have a Mahindra 4500 2wd, my HSU also started fluid leak coming from under the steering wheel, to later find out it was a leak in the top of the HSU. I took it to a repair shop, which they replaced the top seal. It also took me a long time getting out the HSU in my 4500 tractor model, which looks like the one MARVANCE has in his tractor. find the right set of tools to remove this HSU. Ok I got it removed and replaced back in my tractor. I checked and rechecked any leaks around the HSU, and the hoses that connect to the HSU, there was no leaks. But my problem is now that I did not have before I removed the HSU and had the seal replaced, after reinstalling the HSU, my steering will turn the front wheels a little to the left and a little to the right. I cannot make a sharp turn. the steering wheel will just go round and round while the tractor is moving and running, but the front tires turning very little. T turn my tractor around I have to make a large wide turn. Question is. 1. did the shop not set something in the HSU while replacing the seal that is not allowing me to make sharp turns<<< @. did I not sink in the steering wheel drive shaft correctly when reinstalling the steering wheel shaft on the HSU??? 3:is there maybe air in my steering lines. I jacked up the front wheels off the ground, with the engine not running and as I turn the steering wheel, the front wheels do not turn at all. Please give me some advice or what and how to check my steering issues.

I am thinking air in the lines. It might take cycling left and right alot to get it out. You might have to crack a fitting loose to bleed it out. I am not sure. Also, after R&R the HSU, it took a lot of fluid to refill it, with it rebuilt and the lines disconnected.........is your reservoir full?
hugs, Brandi

 

[DJP]

I am thinking air in the lines. It might take cycling left and right alot to get it out. You might have to crack a fitting loose to bleed it out. I am not sure. Also, after R&R the HSU, it took a lot of fluid to refill it, with it rebuilt and the lines disconnected.........is your reservoir full?
hugs, Brandi

THANKS FO THE REPLY BINDIAN: Which hose at what point should I take loose to bleed out the power steering line????I have the Mahindra 4500 2WD There is no fluid bleed cap or bolt either on the HSU/Steering cylinder between the two front tires that let you bleed out any air???

 

[bindian]

THANKS FO THE REPLY BINDIAN: Which hose at what point should I take loose to bleed out the power steering line????I have the Mahindra 4500 2WD There is no fluid bleed cap or bolt either on the HSU/Steering cylinder between the two front tires that let you bleed out any air???

Where ever it is easiest. Usually it's the hose fittings attached to the steering cylinder. Crack it until fluid drips, but not too much. Crank it up and turn the wheel back and forth. It's air if you see lots of bubbles or spurts, then a steady stream. You want a steady stream. Other than that, I have no idea. You could trying removing and reinstalling the unit again. After all that.............................it's likely to be shop error.
hugs, Brandi