Replacing Bobcat loader control valve seals

[andyjax]

Thanks again very much Steve-

Just finished the repair, cranked the old girl up, and to my amazement there were no leaks anywhere! This really saved me a lot of trouble and bucks. Never could have attempted it without your excellent post. Can't thank you enough.

A.Jackson
Brooks, Ga.

 

[willie59]

Nice to hear you did the repair andyjax. :drinkup

 

[DrJim]

Related (New) Thread: Repairing Bobcat Loader Float Detent

I have finally paid a tiny portion of my debt to Willie59 by . . . staying up til 2:15am and posting the year-and-a-half old images of the float detent repair procedures. See the new thread, "Repairing Bobcat Loader Float Detent".

(No, Willie, you can't borrow my pliers! :laugh )

 

[kenmiller]

I have a 2004 773 Bobcat. Because of an accident to my right foot I have very limited strength and movement. Is there a way to adjust the amount of foot pressure required to activate the bucket valve?

 

[crewchief888]

I have a 2004 773 Bobcat. Because of an accident to my right foot I have very limited strength and movement. Is there a way to adjust the amount of foot pressure required to activate the bucket valve?

no.

changing/modifying the centering spring on the spool will only result in a spool that doesnt stay centered.
make sure the pedal pivots freely, and that theres no rust/corrosion or binding at the front of the valve where the linkage connects to the spool.

sounds like you may need to find an AHC equipped machine.

:drinkup

 

[Axel]

I'm planning to reseal the spools as well as the seals on the pump control shafts.

how do you go about cleaning these areas before starting?
i've got a serious amount of greasy mass coating everything.

hot water pressure washer?

 

[willie59]

I'm planning to reseal the spools as well as the seals on the pump control shafts.

how do you go about cleaning these areas before starting?
i've got a serious amount of greasy mass coating everything.

hot water pressure washer?

Yes, hot pressure washer and a lot of time. You likely not only have an oily mess about the control valve and drive pumps, but a pile of goo in the belly of the machine. Bobcat didn't provide large holes to wash this crap out of the bottom of the machine, just small holes here and there depending on the model, and that goo is a PITA to get out of the machine. I've washed on Bobcats for hours and hours and still can't get all that crap out of there. With a Bobcat, you don't get them clean, you only get them clean-er.

Pressure washing around the control valve is no problem, but don't point the jet of water at the drive pump control shafts, you can inject water into the pumps via the failed shaft seal, just clean the area near and around the control shaft, then take the control components off. Once you've exposed the shafts, clean that area with brake cleaner and compressed air to remove the gunk.

 

[Axel]

Remove the 2 allen head screws that secure the lower spool cap. Grasp the cap and gently pull it off the detent mechanism. Make certaing that shaft sticking out the back of the cap is loose and free as your removing the cap. Do not put any pull on that shaft.

View attachment 64740

Grasp the centering spring of the lower spool. Do not grasp or disturb the detent mechanism on the rear of the spool. Gently pull the entire spool assembly backwards out of the valve body.


View attachment 64741

Remove the top spool assembly in same manner by grasping centering spring and pull entire spool out of valve body. Here are the two spool assemblies with old seals and seal retainer disks still on the spools.


View attachment 64742

in my 863F there seems to be barely enough room to even grasp the spool cap.
Did you have to remove many of the hoses to pull the spools out?
I'm guessing it's a good idea to drain the hydraulic fluid first?

also, how much torque did you apply to those allen head mounting screws?

here is a photo of my actuators and control valve



does it look like my control valve is without a spool lock assembly like the one in your photos?
does that mean my spools may be shorter?

BTW it seems I have two different model actuators, one has rubber boots and the other has some kind of aluminum adapter/extension.

what's odd is that this top one with the adapter/extension which I'm assuming is a newer model has failed. while the older and more oil covered bottom lift actuator has continued to work.
do tilt actuators fail more frequently?

 

[crewchief888]

in my 863F there seems to be barely enough room to even grasp the spool cap.
Did you have to remove many of the hoses to pull the spools out?
I'm guessing it's a good idea to drain the hydraulic fluid first?

draining the oil might be a good idea. the hyd tank is gravity feed to the pumps.

you may need to remove any hoses and tubelines that are in the way

also, how much torque did you apply to those allen head mounting screws?

it's a 1/4" bolt, (3/16" allen) and has thread sealant from the factory. i use a long 1/4" dr ratchet to break them loose, and a std length ratchet to snug them back up. (i'd guesstimate you'll be in the 12-15 ft/lb range)

here is a photo of my actuators and control valve

View attachment 130034

does it look like my control valve is without a spool lock assembly like the one in your photos?
does that mean my spools may be shorter?

your valve does not have spool locks, so yes the spool will be a little shorter.

BTW it seems I have two different model actuators, one has rubber boots and the other has some kind of aluminum adapter/extension.

what's odd is that this top one with the adapter/extension which I'm assuming is a newer model has failed. while the older and more oil covered bottom lift actuator has continued to work.
do tilt actuators fail more frequently?

a LOT of times actuator failures are from oil getting INSIDE the actuator.
it's about 50/50 on actuator failures....

View attachment 130035

the bottom actuator is the original, old style of the 2 you have. they are no longer available, and are replaced by the style on the top. it used different allen screws, pin, and the aluminum adapter.

:drinkup

 

[willie59]

Yuk, I think I would pressure wash that thing a bit before I busted it apart, too easy for some of that crap to enter the control valve when you pop the spools out.

And yes, you will leak a little oil. If it's an older model with the high hyd tank, you'll for sure dump some oil. I have a collection of plastic caps that I've accumulated over the years which allows me to pull the spool and shove a handy tapered plastic plug in the hole.

And yes, some models have a hose or two in the way of pulling the spools. Seems I recall one I had to remove the fuel fill hose to get the spool out, just gotta do what ya gotta do.

 

[Axel]

thank you for the answers! my new addiction of asking any bobcat question that pops into mind just got seriously reinforced lol :drinkup

BTW, I'm hoping that the oily seepage on the opposite end of the control valve around the spool end caps will also be resolved after spool resealing?
Is there anything else that might leak at that end? difficult to tell what's going on over there from the awkward view angle and concealing debris...
Trying to make sure I order all parts/seals that are necessary.

 

[willie59]

Spool seals should pretty much take care of the leaks at the control valve, at least it's the most common problem.

 

[mattyt1984]

I am currently doing this job on a 873 bobcat. The lower spool had oil pouring right out of it. Just wondering why does the lower e clip need to be removed? Can it not just be unbolted and the entire spool come off? Can it be installed like this. I to went fishing for spring and check balls. Does the upper spool have detent with springs and balls to be concerned with?
Thanks a lot this was an excellent post

 

[willie59]

I am currently doing this job on a 873 bobcat. The lower spool had oil pouring right out of it. Just wondering why does the lower e clip need to be removed? Can it not just be unbolted and the entire spool come off? Can it be installed like this. I to went fishing for spring and check balls. Does the upper spool have detent with springs and balls to be concerned with?
Thanks a lot this was an excellent post

Yes, a person could likely pull the spool out with the e-clip installed, however, you take the risk of pulling the detent collar off and go fishing. I just find it less stressful to simply remove the e-clip and cap, then I can grab the spring and pull the spool as opposed to pulling on the detent collar.

The upper spool does not have the float detent like the loader arm spool does.

 

[Axel]

Lubricate the lower spool with detent mechanism with assembly grease, place some grease where the seal will fit into valve body bore.

Is it ok to use "assembly lube" instead of "assembly grease"? http://www.permatex.com/products-2/...tex--ultra-slick--engine-assembly-lube-detail

 

[Axel]

Here's the 4 new spool seals and 2 o-rings to seal the spool lock assembly mounting.

View attachment 64744

each kit comes with two O-rings. but it seems that only one end of each spool actually gets them?
I looked at the diagram and as far as I can tell.. it also shows only one o-ring per spool.
since I can't see the other side of the valve without a mirror.. I wasn't sure if maybe I dropped them into the pool of oil below...

 

[willie59]

That's correct axel, each spool gets one of those green u-cup seals on each end of the spool and the two large o-rings seal where the spool lock body mounts to the front of the control valve. And yes, an assembly lube will work just fine.

 

[Axel]

Thank you Willie59, Your response is a confidence booster :cool2

Btw about how much oil might be lost after resealing the spools with loader arms up and lift cylinder fully extended?
I have been able to capture the oil that leaked from the drain hole below, but since the machine is on a slope causing a large amount of oil to remain pooled inside and it's difficult to estimate how much has actually come out of the system.
I have set up a "suck bucket" to remove the oil after I reseal the pump control shafts but will probably purchase some oil sooner.
I was informed that the entire system uses 13 gallons. I'm gonna guess that I've captured about 2.5 gallons and there is another 2-3 pooled inside.
Is there a way to get all 13 gallons out of the system?

 

[Caveman3]

Hello to all,
I am new to this forum and have a problem with my 2002 T190 lift spool. It had been drifting for some time, and then one day the rubber cap blew off and started bleeding hydraulic fluid. Not having seen this forum, I pulled the pump and replaced all the seals, rather than doing an in machine repair. The back side quad seal was the only smoking gun, so I thought I had solved the problem. Got everything running, checked pressures (3200 relief) and flow (16.5 gpm) and no leaks.
Ran the unit for about fifteen minutes and it started leaking again. Raised the cab, and the rubber cap had blown off again and was leaking like crazy.
Could the lift relief valve be causing a problem here? During the rebuild, I did a detailed inspection and found no damage to the spool, and there were no left over parts after the valve was reassembled.
Anybody know what might be going on here?

 

[crewchief888]

Hello to all,
I am new to this forum and have a problem with my 2002 T190 lift spool. It had been drifting for some time, and then one day the rubber cap blew off and started bleeding hydraulic fluid. Not having seen this forum, I pulled the pump and replaced all the seals, rather than doing an in machine repair. The back side quad seal was the only smoking gun, so I thought I had solved the problem. Got everything running, checked pressures (3200 relief) and flow (16.5 gpm) and no leaks.
Ran the unit for about fifteen minutes and it started leaking again. Raised the cab, and the rubber cap had blown off again and was leaking like crazy.
Could the lift relief valve be causing a problem here? During the rebuild, I did a detailed inspection and found no damage to the spool, and there were no left over parts after the valve was reassembled.
Anybody know what might be going on here?

you probably put the seal in backwards....

:drinkup