I was wondering if someone could help me out as far as acquiring information or from past experience work on a hydraulic oil tank leak. My mid 1960's era cat 922B front end wheel loader has a few leaks stemming from the tank itself and also from some of the hydraulic lines that attach to it from the outside. I know there is a members library that might contain parts and service manuals that could help me out but I just don't have the extra money right now to afford the paid membership needed to view those materials. On the bottom of the hydraulic tank there is a thick removable metal plate held in by like 30 or more bolts that seals the bottom of the tank that has a constant slow leak. Also higher up on the tank there are i believe one or two hydraulic lines that use a flange style end fitting to move fluid in and outta the tank that are also leaking. My first question would be, how are those lines sealed to the tank? Is it simply just an o-ring that fits into a small channel in the flange? And then my second question, can I just drain the tank, remove all of the bolts along with the bottom plate and drop it down outta the way or do I need to worry about something inside the tank like a hydraulic oil pump that's gonna fall on my head when I undo the last bolt. I'm just not sure what to expect since I can't find a single shred of information regarding this process. And finally, when all is said and done can I just reseal the bottom with RTV or do I need to make or acquire an actual gasket for the best possible results? If anyone can help me out with some guidance, information, or past experience I would definitely appreciate it. I will try and follow up with some pictures soon. Thanks, Dan

PS: I have included some pictures of the hydraulic tank and lines that are an issue, I have also included a pic of the trans hi/low shift shaft that protrudes through the case which is also leaking fairly consistently. Can any one tell me what type of seal that is on the shift shaft? It almost looks like a bonded washer type seal but I'm not really positive, also can anyone tell me if I can change/replace that seal from the outside of the case. And if any of you guys might know the part #'s for the hydraulic line flange seals on the tank side along with the bottom tank plate gasket and the hi/low shift shaft seal please let me know. Thanks, Dan

The hose ends and steel tube lines use a round rubber o-ring, some early o-rings were metal backed and would sometimes crack and leak and are now updated. The bottom can be removed, get a new gasket and clean well before reassembly, Cat used to supply a green colored gasket cement for hydraulic tanks, I think they use "Form a Gasket #1" Cat Part#4C9501, Its fast drying. Dont use just any ole sealer.

stag jointing paste is another that would be suitable or loctite 515 master gasket no matter what clean the mating surfaces well or the gasket wont seal. a tip is to put a dab of gasket sealer on the bolts as they can leak especially if they are not blind holes. the gasket is either cork or paper you can get these in sheet form from any auto parts or industrial supply. your cat dealer can help with most parts and in particular gaskets and seals.
to cut a gasket use a small ball-pien hammer to gently tap around the edge of the cover and the bolt holes it will cut a gasket that very neat you can also tap just enough to bruise the gasketing and get the outline so you can cut out with scissors you then locate it on the tank with a few bolts and do the same to cut out the middle.

dont use rtv silicone it doesnt work properly with hydraulic oils.

try ebay for service,owners also called operators and parts books. just be sure to get one that covers your machines serial number as cat made changes over the years.

I always wonder just how many under 50 have had someone teach them to make gaskets as you described. Not a hard or that time consuming if the gasket is on flat surface you can get to.

Right on Trainz about silicone does not fare well with oils etc. When the RTV first came out it was hyped to seal about anything and that is so true if it was water!!

a family friend taught me how to do it. he is a automotive mechanical engineer by trade. his one tafe instructor was the late phil irving of repco brabbham engine fame.
he has the tiny ball pien that is just perfect the handle is only 5 inches long.

a retired marine engineer taught me some stuff too.

other things i was shown sealing welsh bungs with litharge powder and glycerine make paste to coat sealing surfaces install and let dry heat is what cures it properly.

my love of stag joint paste comes from dad he worked for a irrigation company working on bore pumps and travelling irrigators they used stag on all fittings and gaskets the tin sat open in the tool box with a brush in it as it dried out you added more metho and give it a stir.

well when you hang around old machinery and collect it from a very young age i was attending displays from 7yr old and since i was small for my age and i asked questions i was shown stuff. i can thank dad for that he involved me in stuff a lot unlike what he was at the same age he got pissoff out the road from my grand father and the when older was expected to know and work in it was a issue when dad got his first car he was expected to be able to do his own maintenance but didnt know how as he hadnt been shown.

ive found its the easiest method to make a gasket beats struggling with pen, paper and scissors. particularly with thin paper it tears so easy

I like to just dial my Cat dealer and have the gasket next day with a perfect fit, lol

Rome wrote:

I like to just dial my Cat dealer and have the gasket next day with a perfect fit, lol

Nothing wrong with that way of doing it. But we are getting to where Cat is not always making gaskets for the machines talked about on here. A very simple procedure to make a gasket with a ballpeen hammer in many cases. Just a bit of knowledge the next generation needs to know about. There is a alternative to using goo out of a tube.
 

loctite make a excellent gasket eleminator but it doesnt work on sheet metal flanges. 515 master gasket will work on sheetmetal covers but they cant be buckled. many machines now dont have gaskets as the are oring sealed. many places dont stock orings they keep the oring maker kits were you cut it to length and gule it together with a special instant adhesive. like white metaling its becoming a lost art.