Going to rebuild Cylinders in JD420 loader

[AzChopp3r]

Or it should say Im going to rebuild them as soon as I figure out how to take them apart.

Since my last post here: http://www.tractorbynet.com/forums/hydraulics/288209-air-hydraulics.html
I decided to go ahead an order the seal kits for the bucket cylinders for the 420 loader on my 4300.

But all I can find on the internet is the cylinders with the hole and the wire retainer you pluck out. It appears mine do not have this. Anybody have knowledge on these cyls?

I have a few pics I will add.

 

[Zebrafive]

Is there an orange plastic split ring in your seal kits? I think it's #17 in the drawing. I've heard it is used to fill a groove in the cylinder bore to allow everything to be removed.
I think the groove is for snap ring #6 on the rod support #10.
#18 is the seal kit

Remove snap ring #3
Push rod support #10 deeper into cylinder bore
Install tool #17 into groove
Pull everything out.

I have NOT done this! So do at your own risk! I might be wrong!

 

[wdchyd]

Is there an orange plastic split ring in your seal kits? I think it's #17 in the drawing. I've heard it is used to fill a groove in the cylinder bore to allow everything to be removed
I think the groove is for snap ring #6 on the rod support #10.
#18 is the seal kit

Remove snap ring #3
Push rod support #10 deeper into cylinder bore
Install tool #17 into groove
Pull everything out.

I have NOT done this! So do at your own risk! I might be wrong!

Yep, :thumbsup:

Just a tip.....with cyl supported in a good heavy-duty vise, before you poke #10 down in the bore, make sure you pull the rod all the way out (oil all drained out)......when you poke the #10 back in the barrel it covers the port and can create an air pocket if you do it with the rod way down in the barrel, so keep it out and the rod gland (#10 ) will go in with the hyd rod (about 3/4" enough to see the inner hidden groove ) then put that plastic spacer in the groove

then use a piece of scrap round stock to stick in the hyd rod eye to help slam it out

 

[kennyd]

Here is a great thread on these type of cylinders: http://www.tractorbynet.com/forums/hydraulics/122281-jd-hydraulic-cylinder-rebuild-help.html

 

[AzChopp3r]

Thank you, thank you shouldnt be a problem now.

 

[AzChopp3r]

Ok just an update -

Both cylinders are rebuilt and operate excellent. As of 3 hours ago when I look outside at the tractor, the bucket has not budged from where I left it.

The seal kits have an updated seal for the piston, which I believe is where the problem lies with these cylinders. I can only imagine that I will eventually be rebuilding the lift cyls in the future.

The first cylinder took about an hour to do since I was being careful, making sure seals and tapers went the right way. The second cylinder took 12 minutes, Lol. Really a no brainer just pay attention to what your doing.

A few things:

The new piston seal is a bugger to get on. Install O-ring first and boil the heavy outer seal for a minute in the microwave. Install over the piston and gently reshape. Set entire piston back into the hot water for a few seconds to warm everything up and the seal will retake shape.

Make sure the orange plastic "tool" is facing the proper way inside the cylinder groove as the groove is tapered.

Thats about it. Just inspect the rod and cylinder for any debris or burrs and reassemble.

Thanks for everybodys help here.