722 bobcat hydraulic leak question

[1953belair]

i just bought my first bobcat,it needs alittle work but its leaking hydraulic fluid bad were the u-joints on engine slide on the spline,coming from the drive pump i believe its called....i have read on the forum and to me it sounds like it is the shaft seal,so i took the motor out,the two rings and the spline off the shaft and now im to the point were i wanted to ask before i messed something up....does the whole shaft and bearing come out of the pump? and i called bobcat and they dont make the shaft seal that i need for it anymore?any suggestions? its a older bobcat 722 hydrostatic

 

[Tazza]

Easy fix!
The seals are available, don't believe Bobcat. I suspect its a Vickers TA1919 pump, the same drive pump as the 743 uses.
If you talk to http://loaderpartssource.com/ and tell them you need the rear shaft seal they will hook you up.
When you have the seal you can proceed, if not, you will drail all your oil unless you pump it out first.
As you have removed the snap ring and spline, get a drill and drill two small holes either side of the seal, just big enough for you to screw in two self tapping screws. Screw them in just far enough for them to bite, about 1/2 to 3/4” in is a bearing, you don't want to hit that. All the shavings will be washed out when the oil comes out with the seal. Use pliers and lever the seal out, its not hard at all.
I made sure i removed and burs from the snap ring before installing the new seal. Slide it over the shaft and into the housing. Use a punch to knock it into place slowly. When you get close, slide the snap ring back in, it won't seat but use that to tap the seal in. When it reaches the correct spot it will snap into place bit by bit. One part will locate, then just work around till its all correctly seated. I did it this way soi knew it was parallel.
Good luck with the job, you have done the hardest part already, getting that pesky splined shaft off! they can be rather tight.

 

[1953belair]

Easy fix!
The seals are available, don't believe Bobcat. I suspect its a Vickers TA1919 pump, the same drive pump as the 743 uses.
If you talk to http://loaderpartssource.com/ and tell them you need the rear shaft seal they will hook you up.
When you have the seal you can proceed, if not, you will drail all your oil unless you pump it out first.
As you have removed the snap ring and spline, get a drill and drill two small holes either side of the seal, just big enough for you to screw in two self tapping screws. Screw them in just far enough for them to bite, about 1/2 to 3/4” in is a bearing, you don't want to hit that. All the shavings will be washed out when the oil comes out with the seal. Use pliers and lever the seal out, its not hard at all.
I made sure i removed and burs from the snap ring before installing the new seal. Slide it over the shaft and into the housing. Use a punch to knock it into place slowly. When you get close, slide the snap ring back in, it won't seat but use that to tap the seal in. When it reaches the correct spot it will snap into place bit by bit. One part will locate, then just work around till its all correctly seated. I did it this way soi knew it was parallel.
Good luck with the job, you have done the hardest part already, getting that pesky splined shaft off! they can be rather tight.

ive called loaderparts and they said they didnt have any seals for the 722 drive pump.so i just tell them its a 743? and when i took the spline off all i seen was two snap rings and a bearing? am i missing the seal or is the seal behind the bearing....i havent ran the bobcat but for just a second because of how much hydraulice fluid it was pouring out from behind the spline.

 

[Tazza]

ive called loaderparts and they said they didnt have any seals for the 722 drive pump.so i just tell them its a 743? and when i took the spline off all i seen was two snap rings and a bearing? am i missing the seal or is the seal behind the bearing....i havent ran the bobcat but for just a second because of how much hydraulice fluid it was pouring out from behind the spline.

It must be different.....
The boys at LPS know what they are talking about, if they don't have seals it won't be the same pump.....
Can you get any details off the pump? are there any numbers stamped on it?

 

[flyerdan]

It must be different.....
The boys at LPS know what they are talking about, if they don't have seals it won't be the same pump.....
Can you get any details off the pump? are there any numbers stamped on it?

Tazz, I can't remember; did the 743 have a two speed hyrostatic pump? Don't know if the hi-lo range was just an add on or a wholly different design. Here is the breakdown for the 700/720 series; if you have a 743 catalog part numbers could be compared.

 

[Tazza]

Tazz, I can't remember; did the 743 have a two speed hyrostatic pump? Don't know if the hi-lo range was just an add on or a wholly different design. Here is the breakdown for the 700/720 series; if you have a 743 catalog part numbers could be compared.

The 743 wasn't two speed.
The pump diagram you have there looks the same.
I do have a 743 parts manual. Can you look up my profile and send me an email? this way i won't forget.

 

[1953belair]

The 743 wasn't two speed.
The pump diagram you have there looks the same.
I do have a 743 parts manual. Can you look up my profile and send me an email? this way i won't forget.

the diagram you have looks exactly the same as the one bobcat sent me for a 722

 

[Tazza]

the diagram you have looks exactly the same as the one bobcat sent me for a 722

Sadly, its not the same as the 743 style pump. Its a weird setup, the rear bearing doesn't run in oil like the other ones do. It also makes it harder to access the leaky seal....

 

[1953belair]

Sadly, its not the same as the 743 style pump. Its a weird setup, the rear bearing doesn't run in oil like the other ones do. It also makes it harder to access the leaky seal....

so does that whole shaft come out on the pump b/c i got it to move about half an inch out and the bearing looks like its almost out of the pump....i didnt want to pull on it to hard and mess anything up before i asked...if i can i would realy like to fix it without taken the pump out of the bobcat

 

[Tazza]

so does that whole shaft come out on the pump b/c i got it to move about half an inch out and the bearing looks like its almost out of the pump....i didnt want to pull on it to hard and mess anything up before i asked...if i can i would realy like to fix it without taken the pump out of the bobcat

I really don't know......
The thing that makes me think you will have to pull the pump to do it is the fact that it looks like that shaft also supports the rotating group. If you remove it, the rotating group and pins that hold pieces in place would probably fall off inside the housing. You can always fish them out later, but it still involves pulling the pump.
I have never worked on one of these p umps though, it may work just fine, but looking at the exploded image alone, i don't believe you will be quite that lucky.

 

[cnord]

I really don't know......
The thing that makes me think you will have to pull the pump to do it is the fact that it looks like that shaft also supports the rotating group. If you remove it, the rotating group and pins that hold pieces in place would probably fall off inside the housing. You can always fish them out later, but it still involves pulling the pump.
I have never worked on one of these p umps though, it may work just fine, but looking at the exploded image alone, i don't believe you will be quite that lucky.

The 722 is a TA1515, it is the older version of the TA1919, They are a lot harder to replace the shaft seal on, its set up almost in reverse from the TA1919. And Yes you will have to pull your pump. The biggest thing like Tazza said, is that the rotating group is relying on the shaft to be in there and when you pull it to get to the seal, the group will fall out of place. The best thing to do is to remove the pump to do this repair. I will check to see if we have a seal for you, we may only carry it in our complete seal kit, which is why the sales guys may not have seen just the seal.

 

[cnord]

The 722 is a TA1515, it is the older version of the TA1919, They are a lot harder to replace the shaft seal on, its set up almost in reverse from the TA1919. And Yes you will have to pull your pump. The biggest thing like Tazza said, is that the rotating group is relying on the shaft to be in there and when you pull it to get to the seal, the group will fall out of place. The best thing to do is to remove the pump to do this repair. I will check to see if we have a seal for you, we may only carry it in our complete seal kit, which is why the sales guys may not have seen just the seal.

I just did some checking and we do have the seal available. If you give us a call back we can further assist you. Ask for Chris, and I will make sure which ever sales rep you get knows whats going on. But we do have that seal in stock and it is sold by itself.