Question about seal kits for repacking cylinders

[edgephoto]

I just bought myself a Cat 426 backhoe. No externally leaking cylinders and they all work with one exception. The boom drops fairly quickly. I am pretty confident the cylinders are bypassing internally. I plan to repack them myself.

I am in the automotive industry and I know OEM parts are generally excellent but sometimes aftermarket items are actually better and sometimes far inferior. You need to know what you are getting.

Since I am not in the heavy equipment world I figured I would sign up here and learn from you all. My questions is what do you guys use for seal kits?

I see HWPARTSSTORE.COM has seal kits for my machine and the price is good. Are these good or stay away?

Thanks for your insight.

 

[Billrog]

I would be inclined to make sure the control valve isn't the culprit a couple 0 rings are much easier and less costly to replace.

 

[heymccall]

Had to repack all 3 sets (6 kits) of my 416Cit/ 426Cit front boom cylinders. Yup, the piston seal has just hardened up. I just put the Cat kits in the cylinders, and I've never done one twice. The kits (seal construction) are revised since the machines were new. Just did the 3rd machine last year.

The HW kit looks identical in color to what I replaced.

376-9011 for my 1yr00448 ($99.53 ea side)

 

[edgephoto]

@Billrog - I am not sure it isn't the control valve. What o-rings are you referring to about the control valve?

I know all the outer(dust) seals are dried and some have pieces missing from them. I am sure they have hardened up over the years. Unless something is frozen repacking a cylinder is not a big deal. I figured I would start there and see what happens. I just hope there is no scoring inside. If there is then I have to decide whether to have it bored .030/.060 over or find a good used cylinder.

I have a manual on its way.

 

[heymccall]

We beat the bejesus out of ours. Marking in all 6 cylinders was minimal, if not non existant.
Myself, I'd repack the 20 year old cylinders first.

There are instances where the control valve, and or load check valves, would be suspect, but, IMHO, not here, this time.

 

[edgephoto]

That was my thought. Start with repacking the cylinders. I will eventually do all the cylinders. I plan to start with the boom, stick and bucket ones first. Then I will do front loader cylinders and then stabilizers and swing cylinders.

The machine is 30 years old and the boom cylinders have been done at least once. There are wrench marks on the gland nuts.

Anyway back to my original question.....OEM Caterpillar seal kits or are the aftermarket ones ok? Aftermarket seems to be about half the price. But I do not want half the quality.

 

[Tenwheeler]

Start it cold and hold the control lever for that one way and then other. Maybe 3 minutes at a time. Repeat it needed. If the piston seals are bypassing the cylinder will be warm from fluid flowing through it.

 

[edgephoto]

Thanks. Great tip!

 

[Check Break]

Hercules Bulldog makes good aftermarket seal kits. If you can't find them for half the price of CAT, I'd stick with CAT.

 

[Vetech63]

Make sure you have a good quality 1" breaker bar, a 10 ft cheater pipe, and 2 gorillas when you get ready to remove that piston! …………..some of those will drive you to drinking.

 

[DMiller]

Aftermarket is OK if not a daily user in a severe duty assignment company, OE Cat is Better if takes a beating.

 

[Billrog]

I agree with Check Break Hercules Bulldog seals are where I purchase mine for the cat at a fraction of the price .

 

[DMiller]

Herc is about all the aftermarket the shop that supplies my parts sells.

 

[heymccall]

I put Bulldog seals in the stick cylinder of my 5k hour 322B 1YS, and then replaced them twice. Lasted less than a month each time (piston bypassing). Put Cat seals in and never looked back. Sold the machine with 17k hours on it.

But, for backhoe cylinders (no big tools for disassembly, no crane for removal), I'd go Bulldog.

 

[edgephoto]

I guess I will go with my instinct and buy genuine Cat seal kits. Some of the aftermarkets are 50% of Cat price but to save $50 and have to do a ob over again sooner than expected is not worth the savings. I see kits on eBay for $20 but I am sure those are junk.

I was curious about HW Parts but since nobody mentioned them I will skip.

I am a homeowner and bought this machine to clear a heavily wooded piece of land I plan to build a house and barn on. I may not make a living with it I do not want to spend my free time fixing it instead of working it.