Weekend Freedom Machines banner

1 - 20 of 44 Posts

·
Registered
Joined
·
279 Posts
Discussion Starter #1
how can I take my 420 hydro pump out of my 420 with out pulling my engine of transmission??
 

·
Registered
Joined
·
2,402 Posts
You could cut the driveshaft. Seriously though, the engine or transmission need to move. My usual technique is to slide the engine forward a bit by removing the motor mount bolts, and removing the bolts holding the driveshaft onto the engine. With or without tilting the engine a bit for more room, I can usually get the driveshaft to slide off the hydro pump.
 

·
Registered
Joined
·
2,072 Posts
From another post/forum, OP believes pump is bad.

A word of caution on reassembling: Everything MUST be 110% clean, operating room clean! A piece of debris that's .0005" to .002" can destroy your new pump, valves, cylinders! Dirt/debris in a hydraulic system means instant death to the unit. Bob
 

·
Registered
Joined
·
2,194 Posts
Bob is 110% correct. I spent about 9 months working for a Caterpillar dealer rebuilding pumps and motors. That shop was ridiculously clean. No windows. I would eat lunch and take breaks in the bed of my truck to soak up some sun. I left there and went to do construction. I’m a flower I guess...I wilt without sunlight:lol: On a side note, their paint is amazing! Only paint I’ve ever seen that doesn’t fisheye on grease or oil, and it sticks to grease!
 

·
Registered
Joined
·
2,072 Posts
AHH! Whole different story! That's called a charge pump. Drop drive shaft, take 2 bolts out...or pry seal out... and you're home free!

Another word of caution about messing with the charge pump. There's a small, maybe 1/8" dia., pin that drives the gerotor...a kind of gear looking part inside the pump... and MANY people have dropped this without knowing it was even there! Unless you're 100% positive it's in place, dismantle and check.

Clean all debris/rust from drive shaft yoke where it slides through the seal. Check end of drive shaft for a wear groove. If worn, you may have to replace yoke or still end up with a leak! Lube shaft & seal with oil before reassembling. Bob
 

·
Registered
Joined
·
279 Posts
Discussion Starter #8
okay, the pin is still there (I watched a you tube video before I replaced it and he mentioned the pin) I had too pull the hole thing the charge pump is on to replace the seal be cause of how my tractor is.
 

·
Registered
Joined
·
279 Posts
Discussion Starter #9
I got my new filter for my 420 Hydro today and I was wondering is there any thing I need too Do other then change the filter and refill my transmission with oil? if I do it that way will it air lock?
 

·
Registered
Joined
·
279 Posts
Discussion Starter #11
Make sure the tractor has enough hydraulic fluid.
Place the tractor in reverse and rev engine normally. When and if it starts to move, run it backwards for awhile until it operates normally in reverse. After doing the reverse thing try the forward position,

so is that what I need too do?
 

·
Registered
Joined
·
2,072 Posts
Yes. Personally, to me "rev engine normally" would be no more than 1/2 throttle. Also, move outer lever (for rockshaft cylinder) until engine changes sound. Then move lever in opposite direction until engine changes sound. Once you get tractor to move, do some full right circles and then full left circles. Bob
 

·
Registered
Joined
·
279 Posts
Discussion Starter #13
Okay I'll try it and see how it goes.
 

·
Registered
Joined
·
2,072 Posts
Andy, Just to inform/enlighten you a little! The hydro does more than just propel your tractor.

The charge pump delivers oil to 2 places, your power steering valve & the hyd valve with the levers, and then to the hyd pump (for lubrication if Fwd/Rev is in neutral). Draining the hydro oil may...or may not!... drain oil from these parts. Operating the steering and the lever pushes oil through these valves and pushes any air back into the hydro to be vented out. Also, don't be too surprised when nothing happens for a minute or so. Your filter is empty and needs to be filled with oil and nothing happens until it is full.

Once everything works, shut engine down, wait 5 or 10 minutes, and check level. Any air that was in the system has been replaced with oil and level may be a little low. Bob
 

·
Registered
Joined
·
279 Posts
Discussion Starter #15
Okay that makes scene I just replaced the seal that goes around my drive shaft that's why I wanted too know what I should do.
 

·
Registered
Joined
·
279 Posts
Discussion Starter #16
I ordered the wrong filter :cry: so I'm gonna get a new one tomorrow.
 

·
Registered
Joined
·
2,072 Posts
Andy, Wipe area on hydro where filter seats. Cloth is good, and paper usually leaves small fibers which can work their way into system. Do a final wipe with a CLEAN finger. Next, fill filter about 1/3 full of oil and put a small amount of oil around the gasket. Install filter...with the thoughts that some oil is going to run down your arm, as it does mine! Fill hydro and bled air per above instructions. Bob
 

·
Registered
Joined
·
279 Posts
Discussion Starter #18
Thanks Bob I'm getting the right filter today!
 

·
Registered
Joined
·
279 Posts
Discussion Starter #19
I put my oil filter on my 420 and filler it with oil started my tractor and used the steering (it had NO power assist) and I pushed the levers and nothing happened......and my tractor did not move for 5+ minuets...
 

·
Registered
Joined
·
2,072 Posts
Could be a major or minor problem!
Remove oil fill cap and check oil level. Cap is vented and could be clogged giving false reading.
Loosen oil filter about 2 turns, oik should come out. If not, remove filter and fill about 1/3-1/2 full of oil. QUICKLY install filter as oil will run out!
Start tractor, go to rear and verify shaft coming out of hydro unit is rotating.
If you didn't have to add oil and shaft is rotating, could be a bad charge pump.

Do a search online for TM1590 and you'll find free downloads. LOTS of good info in there. Bob
 
1 - 20 of 44 Posts
Top