Piston access via oil pan on B7100 HST

[Cryptohorse]

New here but had my B7100 for quite some time.

I'm trying to get access to the bottom of the engine via removing the oil pan. However there is a drive shaft overlaying it and I'm not sure where I should disconnect it and if I do whether a whole lot of oil or other fluid will come out.

Secondly there is a water pipe which i think sends coolant to the hydrostatic fluid pump. It overlays the oil pan bolts on one side so they can't be removed without disconnecting it. I've taken one end off the radiator. Looks impossible to remove the end under the steering wheel without taking off the drive shaft.

Seen a few comments in here about people doing this but no detailed description so any advice or handy hints would be appreciated.

 

[North Idaho Wolfman]

You can remove the cover off the propeller shaft without losing any fluid, and then remove the shaft.
The "water pipe" is a hydraulic fluid cooler line and you should be able to remove the clamps and move it.

But this leads to the question what are you trying to accomplish?
If you simply want to look at the bottom skirt of the pistons, yea you can do that, besides that your not going to be able to do much of anything else.

What is the problem your trying to figure out?

 

[Cryptohorse]

You can remove the cover off the propeller shaft without losing any fluid, and then remove the shaft.
The "water pipe" is a hydraulic fluid cooler line and you should be able to remove the clamps and move it.

But this leads to the question what are you trying to accomplish?
If you simply want to look at the bottom skirt of the pistons, yea you can do that, besides that your not going to be able to do much of anything else.

What is the problem your trying to figure out?

Engine had 1640 hours and was blowing quite a lot of smoke. Had a leaking oil pressure switch which led to what i thought was a head problem from lack of oil. Replaced the head gasket and oil seals but there was a lot of carbon gunk around the center cylinder exhaust valve. Still not working smoothly so I want to pop the pistons out and see if there is any damage. If so I believe I can get a rebuild kit to replace them. Not at all confident about splitting the tractor and getting into the engine as a separate unit. Also on a pension so I can't afford to pay anyone else to do the work.

 

[North Idaho Wolfman]

Engine had 1640 hours and was blowing quite a lot of smoke. Had a leaking oil pressure switch which led to what i thought was a head problem from lack of oil. Replaced the head gasket and oil seals but there was a lot of carbon gunk around the center cylinder exhaust valve. Still not working smoothly so I want to pop the pistons out and see if there is any damage. If so I believe I can get a rebuild kit to replace them. Not at all confident about splitting the tractor and getting into the engine as a separate unit. Also on a pension so I can't afford to pay anyone else to do the work.

Ok now that answers a lot.
You can't get the pistons out of the bottom because the crank has to come out the back.
Splitting these little guys is easy.
You can unbolt the frame from the engine and remove it and the axle in one shot.
I order to do a proper rebuild on these you need to take the engine all the way down and have new sleave pressed in and bored to size.
You might get lucky (RARE) and be able to just use oversized pistons and rings to get it back to spec, you will need to take it all apart and measure the bores to see where the engine is at.

 

[Cryptohorse]

Ok now that answers a lot.
You can't get the pistons out of the bottom because the crank has to come out the back.
Splitting these little guys is easy.
You can unbolt the frame from the engine and remove it and the axle in one shot.
I order to do a proper rebuild on these you need to take the engine all the way down and have new sleave pressed in and bored to size.
You might get lucky (RARE) and be able to just use oversized pistons and rings to get it back to spec, you will need to take it all apart and measure the bores to see where the engine is at.

I believe I can undo the connecting rods and remove the pistons vertically. The head is already off. Is that not possible? I'm not really trying to do a proper rebuild. Just hoping to get it operating a bit better than it was before. All I use it for is moving a few hay bales and running a pump off the PTO a few hours per week.

 

[North Idaho Wolfman]

I believe I can undo the connecting rods and remove the pistons vertically. The head is already off. Is that not possible? I'm not really trying to do a proper rebuild. Just hoping to get it operating a bit better than it was before. All I use it for is moving a few hay bales and running a pump off the PTO a few hours per week.

Yes you'll be able to pull the pistons like that.
At least hone the cylinders to get new rings some chance of sealing.

 

[Cryptohorse]

Yes you'll be able to pull the pistons like that.
At least hone the cylinders to get new rings some chance of sealing.

Will do that. Thanks for the advice.

I'm at the stage where I have slid off the connector on the front drive shaft and removed the three bolts connecting it to the bell housing behind the front axle. I can slide the shaft housing towards the back of the tractor but it doesn't disconnect the shaft from the front axle so I can't get it right out of the way.

Any hints about how I can do that?

 

[North Idaho Wolfman]

Loosen the 2 clamps on the boot (yellow) that will let the shield slide back giving you room to get to the roll pin (green) on the front U-joint.

 

[Cryptohorse]

Loosen the 2 clamps on the boot (yellow) that will let the shield slide back giving you room to get to the roll pin (green) on the front U-joint.

View attachment 144405

Thanks for the advice. I knocked out the roll pin OK. However the shaft won't slide far enough to disconnect it. Seems to be jammed by the other end of the shaft not being able to move. I can get the spline about 6 or so mm away from the U-joint where the roll pin was but not far enough to clear the U-joint.

 

[Cryptohorse]

Upon further investigation it looks as if there is a rear rollpin #120 which I will also need to remove to give enough play to pull the spline out of the first U-joint bracket #170. Does that seem right? Otherwise the shaft seems too long to free up just from the front end.

 

[North Idaho Wolfman]

Upon further investigation it looks as if there is a rear rollpin #120 which I will also need to remove to give enough play to pull the spline out of the first U-joint bracket #170. Does that seem right? Otherwise the shaft seems too long to free up just from the front end.

There might be dirt and such not letting the shaft slide enough to get it apart.

It's easier to remove #200 and pull the whole assembly out of the way.

 

[Cryptohorse]

Upon further investigation it looks as if there is a rear rollpin #120 which I will also need to remove to give enough play to pull the spline out of the first U-joint bracket #170. Does that seem right? Otherwise the shaft seems too long to free up just from the front end.

Looked as if there was a half inch of spline left on the shaft to tap it down from the front axle end. I did that gently and it eventually came free. How I have access to the water cooling lines for the HTS. There are two nuts locking it together and they seem impossible to shift with normal force. Any hints? I have to move them out of the way to get access to the bolts holding one side of the oil pan.

 

[North Idaho Wolfman]

Looked as if there was a half inch of spline left on the shaft to tap it down from the front axle end. I did that gently and it eventually came free. How I have access to the water cooling lines for the HTS. There are two nuts locking it together and they seem impossible to shift with normal force. Any hints? I have to move them out of the way to get access to the bolts holding one side of the oil pan.

It's a HYDAULIC cooling line, you need to turn the 2 nuts in opposite directions to unlock the fitting, they will be tight!

 

[Cryptohorse]

They are HYDAULIC LINES, you need to turn the 2 nuts in opposite directions to unlock the fitting, they will be tight!

I realise that they need to be unlocked in opposite directions. Just hoping they are threaded so that the one closer to axle gets pulled down and the one closer to the hydraulic pump has to be pushed up. They do only have cooling water in them from the heat pump on the front of the radiator so there may be rust or something making them hard to shift. Probably been locked tight for 30 years!

 

[North Idaho Wolfman]

I realise that they need to be unlocked in opposite directions. Just hoping they are threaded so that the one closer to axle gets pulled down and the one closer to the hydraulic pump has to be pushed up. They do only have cooling water in them from the heat pump on the front of the radiator so there may be rust or something making them hard to shift. Probably been locked tight for 30 years!

I don't think you understand, there is no heat pump, there is a hydraulic fluid cooler.
Yes we might have a OZ to US conversation conversion issue on name of parts.
But if that line has water in it you have a serious problem.
That hydraulic line goes to the HST and if the HST has water in it the HST will be destroyed.
HST's do not like water at all!
Yes you have the direction of the loosening right.
You could also remove the banjo bolt fitting on top of the HST and get enough movement to get to the bolts.

 

[Cryptohorse]

I don't think you understand, there is no heat pump, there is a hydraulic fluid cooler.
Yes we might have a OZ to US conversation conversion issue on name of parts.
But if that line has water in it you have a serious problem.
That hydraulic line goes to the HST and if the HST has water in it the HST will be destroyed.
HST's do not like water at all!
Yes you have the direction of the loosening right.
You could also remove the banjo bolt fitting on top of the HST and get enough movement to get to the bolts.

View attachment 144503

Got it undone! The banjo bolt idea was a good one. Just have me enough wriggle room to get my shifter onto the bolts. So now I have the pan bolts exposed. Will take that off next once I've drained it. Will lt you know what I find with the pistons. hopefully this will be a useful thread for anyone else with the same problem.