I am going to attempt repacking a tilt cylinder on a Cat 951C and I would appreciate any advice. I just did a cylinder on a Case backhoe thanks to some info I found snooping around these forums. Those pictures in the excavators forum of Lashlander putting seals in the cylinder on his 345 are awsome. I don't think this job will be quite that massive but the procedure will be similar. Anyway, the questions I have are... Can I do it without any special tools. The Cat manual says you need an expander to get the piston seal on and a compressor to get it back into the bore. I think not. I picked up the kit from the Cat dealer and it looks pretty standard. I also noticed from the diagram that the piston fits on a taper on the rod. Does this press on or will it pop off easily? Please let me know if anybody has experience with this.
Personally, I don't have much knowledge with your cylinder in question. Just pay attention to the way you dis-assemble the unit and the way seal lips are facing.
Packing No disrespect but refer to some form of reference because I have taken some apart that where assembled wrong. History repeats itself.
that piston should pop off of the tapered end of the rod fairly easy with a few good taps from a hammer. make sure you don't hit it on the edge and mess up the edge though. It's a pretty straight forward process as you said but if at all possible I'd try to find a diagram as said above to make sure you put it together correctly. I've repacked multiple cylinders that had been reassembled wrong(seal lips facing wrong way). And lastly make sure everything is spotless before reassembly. Cleanliness is next to godliness especially in a hydraulic system.
there should be a special instruction included in the kit that will tell you how the seals are oriented. if you don't use the expander on the seal ring then wrap it with some card board and put a hose clamp on it to shrink it back into place. also clean the outside of the wiper seal off with contact cleaner and scotch brite, there is a rust inhibter on it that will prevent it from bonding to the head. glue it into the head with retaining compound. lastly make damn sure you get the piston nut tight, very tight, allot of locals in our area will bring there rods and pistons to the dealer to have them loosend, they will then reseal it themselves and return to have the nut retorqued. 951 Tilt Cylinders (5J9815, 5J9816, 7J9833, 7J9834, 8J5939, 3G8083) (1) Torque for nut ... 1000 ± 120 lb. ft.(1350 ± 160 N·m)
Hey, I got 'er done! I will try to post some pictures when I get time. It wasn't a bad job, but it sure helps to have the right equipment to do it. Thanks for all the suggestions! I had the service and parts manuals so I got everything together correctly. The seal kit had several diagrams and instructions to go by also. Thanks again.
Good job Smitty and well done, thanks for the update....................................now wheres the pictures
Good tips here. I've had ripper cylinders resealed incorectly in the past, it all depends on which way the cylinder is being used with the highest amount of required pressures. The seals can be installed wrong so be careful. On other words, (newbie alert) I have a 951C myself and it is good to hear from someone else who runs the old iron. Let me clarify though as sadly my 951C caught fire a few months ago and I'm still mumbling around wondering if I should rebuild her or let it go for parts. I tried cranking it over and she is leaking fuel around the inlet side of the injector pump so it is not looking good. Runs good with a light mistig of ether though.
Great thread, I have two lift cylinders on a jd555a highlift that I am going to have to repack. Thanks for the info and insight guys!:thumbsup