Replacing Bobcat loader control valve seals

[willie59]

Glad to hear you got is sorted out sid rust.

 

[FlatTire]

I have an update for the thread. Changed the control valve seals on a 753C recently, they're a kind of a PITA compared to the 763G and 773G. Because of the mounting location of the control valve, doesn't do any good to remove the machine side cover, it won't give you access to the control valve, everything has to be done from the topside. And the front of the control valve is a Bi-itch to get to because the loader arm manual descent valve body is in the way. Aside from this, the repair is pretty much the same method as other models, we'll just cover a few differences doing the 753C.

First, like with other models, remove the bucket, raise loader arms, install safety prop, and tilt bucket coupler all the way forward (dump). Make certain you have cleaned the dirt and crap in the belly of the machine under the control valve, you're going to need that hole open in the belly of the machine to drain oil into a pan when you pull control valve spools out.

The 753C had the hyd tank behind operators seat, you're going to have to drain the tank or you'll lose your oil when replacing control valve seals.

View attachment 71722

Best way to drain this tank? LoL, you guessed it, the suck bucket. Ha ha ha ha

View attachment 71723

Here's one of the problems you're going to have on this model, getting to the allen head screws that hold the dust boots and seal retainers on the front of the valve body, you can't get your hands in there for all the stuff in the way.

View attachment 71724

Now, removing the control valve to perform repairs would be a major disconnect deal, yuk! Likewise, removing that valve body for loader arm descent wouldn't be a piece of cake, no real good options here. Here's about the best you can get to access the front valve components.

Disconnect and remove this crossover pipe.

View attachment 71725

Remove the hose connected to the T fitting.

View attachment 71726

Your thread with instructions is greatly appreciated Willie!! I just finished the spool seals on my 753, and i felt like a Chinese body contortionist trying to get to all the allen heads!

 

[Mr. John]

Thank you Willie59! Your initial post is going on 11 years and there isn't anything better out there. I completed replacing the new seals in a 773F, slightly different than the "G", but on page 4 of the forum explains the difference in the seal placement from excalibor67 and confirmed by Willie59. The "F" series can be accessed from the top without going through the side access panel. Take out one spool at a time...taking out the top one first giving better access to the allen bolts on the bottom one. It is a tight fit accessing the bolts along the side wall. It is a "feel" process rather than "sight" getting the allen wrench into place. Assembly was considerably quicker by complete assembly and installation of the bottom spool first then the top. This allows for easier access to starting the bolts. Also, rather than a "seal kit" at $85 from Bobcat and a 3 week wait, only 4 seals are needed at $3.80 "on-line" or $4.25 through Bobcat which they have in stock. The seal kit gives seals an o-rings for numerous applications. After a half day of labor, it is up and running with no leaks. Well worth doing it yourself and the $17 for seals. Thanks guys!!

 

[shehorn]

I have read this post a few times but still struggling where to start. Would you recommend taking the lock valve off to gain access to the Allen bolts. This is a 773 machine.

 

[gta18]

Hi Guys,

I just purchased an unknown hours 1994 753H I believe because of it having 1 aux set pair on the left front side. I'm slowly fixing things on it and have so far have unstuck the 2 sov body's for the aux and got that working.

Now I'm onto troubleshooting the Lift arm And Bucket tilt that slowly (about an hour) the arm goes from fully raised to down to the ground.

Will the leaking spool seals cause this problem? It happens to both lift and trebuchet tilt.

Thank you

 

[Shay downey]

Well after like 3 hours I've read through all of these comments and Willie59 you sure know your stuff. However I've got a 92 I belive 753 pretty sure its a "c" series and I need to pull the whole valve body because the seals are leaking and I've tried doing them 3 times now and the same one is still leaking. I just can't find any info on pulling the whole damn thing. Any suggestions or tips before I really tear into this thing? I'll try to upload some pics of it.