753 leaking fluid into chain case

[jarrettfikel]

I was wondering if anyone had any way of finding which side was leaking?

 

[Tazza]

Seals are cheap enough, do both sides. If one side failed, the other may not be far behind.

 

[7LBSSMALLIE]

Seals are cheap enough, do both sides. If one side failed, the other may not be far behind.

would also reccomend pulling center chain case cover. put a prybar between carriers and check for brg slop. on carriers. dont forget to repllac certs seal on motor. (domed white speckled blue) and honsetly not a bad time to replenish seals in motors . they are on the bench. and may be cause of carrier seal failure. due execcisvive internal leakage. so yea the way i roll with this job is A remove center chain case cover. suck out oil. inspect chains (lift em should not slap covers if they do they are stretched.) B pry bar on carriers (between em should have no radial runout nor end play to exceed about three thousandths (should be o) . bench the motors tear down inspect reseal. TIME THEM. r@r carrier seals. refill button up. chain case now be happy. on a 753 this should be last time you are ever in there. ax seals and brgs differant story. have a good time it aint a bad job. kinda lets you right into the guts of machine.

 

[jarrettfikel]

would also reccomend pulling center chain case cover. put a prybar between carriers and check for brg slop. on carriers. dont forget to repllac certs seal on motor. (domed white speckled blue) and honsetly not a bad time to replenish seals in motors . they are on the bench. and may be cause of carrier seal failure. due execcisvive internal leakage. so yea the way i roll with this job is A remove center chain case cover. suck out oil. inspect chains (lift em should not slap covers if they do they are stretched.) B pry bar on carriers (between em should have no radial runout nor end play to exceed about three thousandths (should be o) . bench the motors tear down inspect reseal. TIME THEM. r@r carrier seals. refill button up. chain case now be happy. on a 753 this should be last time you are ever in there. ax seals and brgs differant story. have a good time it aint a bad job. kinda lets you right into the guts of machine.

thanks for the info. I have a question about the drive motor . you said to tear completely apart and replace all seals and O-rings inside the drive motor ? if so is that a difficult job and do I need special tools to complete this? I checked and a reseal kit is $100 at dealer. a new drive motor is $1200.

 

[jarrettfikel]

thanks for the info. I have a question about the drive motor . you said to tear completely apart and replace all seals and O-rings inside the drive motor ? if so is that a difficult job and do I need special tools to complete this? I checked and a reseal kit is $100 at dealer. a new drive motor is $1200.

I was also told to check and replace the case drain line filters, because they may be clogged causing to much pressure to build up. I'm not sure what they cost but I'm sure looking at how this machine was maintained that they have never been replaced.

 

[7LBSSMALLIE]

I was also told to check and replace the case drain line filters, because they may be clogged causing to much pressure to build up. I'm not sure what they cost but I'm sure looking at how this machine was maintained that they have never been replaced.

100 bucks a side money well spent. only tool will be a tourque wrench and yes case drains imperative mind yoy im assuminining youre keepining this machine, and want years of trouble free service. of course you can just throw two carrier seals at and see what happens . but if you got the componets on the bench ? and just might be cause of failure?

 

[bobbie-g]

100 bucks a side money well spent. only tool will be a tourque wrench and yes case drains imperative mind yoy im assuminining youre keepining this machine, and want years of trouble free service. of course you can just throw two carrier seals at and see what happens . but if you got the componets on the bench ? and just might be cause of failure?

Seems like most of the case drain filters are the same. The elements/o-ring kits are about $20 ea. I suppose the bronze elements could be cleaned with carb cleaner, but I've never tried. I did get an extra filter/aluminum housing, so when I change the filters, I can just remove one housing and replace it immediately with another to keep oil leakage to a minimum. Then rebuild that one and swap it out with the next, etc. ---Bobbie-G

 

[jarrettfikel]

Seems like most of the case drain filters are the same. The elements/o-ring kits are about $20 ea. I suppose the bronze elements could be cleaned with carb cleaner, but I've never tried. I did get an extra filter/aluminum housing, so when I change the filters, I can just remove one housing and replace it immediately with another to keep oil leakage to a minimum. Then rebuild that one and swap it out with the next, etc. ---Bobbie-G

so I just got back from vacation . all the parts are here that I ordered and I removed the first drive motor. the motor carrier seal on the machine is a two piece that looks just like the one in the repair manual 1993 . the seal that bobcat sent me is a one piece and about 4 1/4 " in dia. the old one is about two " dia . I'm wondering if the new seal is just a new type or did I get the wrong part? has anyone ran into this before?

 

[Tazza]

so I just got back from vacation . all the parts are here that I ordered and I removed the first drive motor. the motor carrier seal on the machine is a two piece that looks just like the one in the repair manual 1993 . the seal that bobcat sent me is a one piece and about 4 1/4 " in dia. the old one is about two " dia . I'm wondering if the new seal is just a new type or did I get the wrong part? has anyone ran into this before?

I have only ever replaced seals that were one piece and quite large. Not sure what the ones were for that you were supplied with...

 

[jarrettfikel]

I have only ever replaced seals that were one piece and quite large. Not sure what the ones were for that you were supplied with...

they sent me one piece . the ones that were in the there are three piece . two seal and a seal carrier.

 

[jarrettfikel]

they sent me one piece . the ones that were in the there are three piece . two seal and a seal carrier.

ok one side is done new seals in the drive motor , new inline filter and new carrier seal . the one piece seal is the replacement for the three piece . this must be the first time this seal has been replaced.replacing the seals in the drive motor was fairly simple . thanks for the advice

 

[7LBSSMALLIE]

ok one side is done new seals in the drive motor , new inline filter and new carrier seal . the one piece seal is the replacement for the three piece . this must be the first time this seal has been replaced.replacing the seals in the drive motor was fairly simple . thanks for the advice

youre welcome, and thanks for the feed back. it is nice to know results.

 

[jarrettfikel]

youre welcome, and thanks for the feed back. it is nice to know results.

ok both sides are done . I put new seals in both drive motors replaced both inline filters and replaced both motor carrier seals . I found one of the hoses going to the inline filter was leaking and replaced that also . also new hydraulic fluid and filter and oil in chain case .new air cleaner . ran it for a coulple hrs and no leaks visable and the hydraulic fluid level is now staying full . the left side is still slower than the right and when I start it the machine wants to turn left for a bit .I ran it on jack stands back and forth to break in the new seals and at a stop the right wheels were moving forward and the left was moving backwards .the more I used it the less it did this . I think it might need adjusting does anyone have any input on this thanks

 

[7LBSSMALLIE]

ok both sides are done . I put new seals in both drive motors replaced both inline filters and replaced both motor carrier seals . I found one of the hoses going to the inline filter was leaking and replaced that also . also new hydraulic fluid and filter and oil in chain case .new air cleaner . ran it for a coulple hrs and no leaks visable and the hydraulic fluid level is now staying full . the left side is still slower than the right and when I start it the machine wants to turn left for a bit .I ran it on jack stands back and forth to break in the new seals and at a stop the right wheels were moving forward and the left was moving backwards .the more I used it the less it did this . I think it might need adjusting does anyone have any input on this thanks

old school steering adjusment.. first inspect, hydrostatic drive pump for external leaks. specificaly pintle shaft seals and hydrostatic input shaft seal. next check hydrostatic pump mount bolt ?is it missining is it sheared off in stat. either of these conditions will dictate as to how to proceed with repar.

 

[jarrettfikel]

old school steering adjusment.. first inspect, hydrostatic drive pump for external leaks. specificaly pintle shaft seals and hydrostatic input shaft seal. next check hydrostatic pump mount bolt ?is it missining is it sheared off in stat. either of these conditions will dictate as to how to proceed with repar.

ok the pump is clean and no leaks are present . the mounting bolt on the right front is missing I'm gonna order two bolts and a tilt cylinder repair kit because that blew out and It's leaking too much to run the machine at the moment . how many bolts are there on the pumps ?

 

[jarrettfikel]

ok the pump is clean and no leaks are present . the mounting bolt on the right front is missing I'm gonna order two bolts and a tilt cylinder repair kit because that blew out and It's leaking too much to run the machine at the moment . how many bolts are there on the pumps ?

ok the manual only shows one bolt on the right which is missing . then a couple on the left which go to the hydrostatic mounting flange which are still intact . so Monday I will order two of the one that is missing and reinstall. then I will check operation and report back thanks

 

[mmsllc]

ok the manual only shows one bolt on the right which is missing . then a couple on the left which go to the hydrostatic mounting flange which are still intact . so Monday I will order two of the one that is missing and reinstall. then I will check operation and report back thanks

The lower right-most hydraulic pump mounting bolt seems to either vibrate loose or shear / break off from vibration. ((This bolt I am talking about is a 1/2" diameter bolt & has a spacer that runs through the engine mounting bracket & into the rear of the hydraulic pump.)) If you are LUCKY, then the bolt simply backed out. They can be difficult to reach, but much easier to install as long as it backed all the way out.