Tilt cylinder wont hold position (853)

[Fishfiles]

had a few hours today after work so i drained hydarulic fluid, removed the hydraulic tank and removed the spool for the steering levers at the hydrostatic block. I'm wondering that there are no o-rings on the spool:

I dont really understand the drawing on pdf page 93 of the parts list.
Should i try to get o-rings ? Two or only one at the top of the spool ?
Sorry for asking so many stupid questions, i simply never worked with hydraulics before.

take off the spring and there should be a white back up ring and oring on the top of the spool

 

[ard]

take off the spring and there should be a white back up ring and oring on the top of the spool

Thanks, yes already found the o-ring and washer, they are ordered and should be delivered next week.
Got the spool seal kits and removed one spool from the control valve today. As shown in the parts manual there are two seals

There are two black seals but the seal kit contains a lot more, what are the two orange ones, the two yellow ones and the large o-rings used for ?

The kit i got was 6816250, the dealer told me it was a replacement for 6823605

 

[Tazza]

Thanks, yes already found the o-ring and washer, they are ordered and should be delivered next week.
Got the spool seal kits and removed one spool from the control valve today. As shown in the parts manual there are two seals

There are two black seals but the seal kit contains a lot more, what are the two orange ones, the two yellow ones and the large o-rings used for ?


The kit i got was 6816250, the dealer told me it was a replacement for 6823605

I believe the kits cover a few machines, you won't need all the seals and O-rings in the kit. Just use the ones that match what you took out.

 

[ard]

I believe the kits cover a few machines, you won't need all the seals and O-rings in the kit. Just use the ones that match what you took out.

Installed the seals today and it seems to be ok, will see when i will work a bit with the machine. However, BOSS now shows AF2 (Air Filter) again, both filters are new. In addition is shows AF6 (Air filter sensor). Does someone know how that sensor works, there is no description in the service manual. It shows up as a closed switch in the schematic but it is not closed (engine on or off). Cabling from the sensor to the BOSS unit is ok. I have not yet removed the sensor, that's open for next weekend ;.), should i order a new one ? Btw, is there a description of the symbols on the BOSS display (or is the symbol shown always the same as the code ?)

 

[Tazza]

Installed the seals today and it seems to be ok, will see when i will work a bit with the machine. However, BOSS now shows AF2 (Air Filter) again, both filters are new. In addition is shows AF6 (Air filter sensor). Does someone know how that sensor works, there is no description in the service manual. It shows up as a closed switch in the schematic but it is not closed (engine on or off). Cabling from the sensor to the BOSS unit is ok. I have not yet removed the sensor, that's open for next weekend ;.), should i order a new one ? Btw, is there a description of the symbols on the BOSS display (or is the symbol shown always the same as the code ?)

The sender could be bad, it should screw into the ait filter box where the hose goes to connect to the inlet manifold. It's essentially a vaccum switch. When it reaches a set value it turns on or off to tell the operator that the air filter(s) are causing too much of a restriction. I guess you could even have a bad connector/wire somewhere too....

 

[ard]

The sender could be bad, it should screw into the ait filter box where the hose goes to connect to the inlet manifold. It's essentially a vaccum switch. When it reaches a set value it turns on or off to tell the operator that the air filter(s) are causing too much of a restriction. I guess you could even have a bad connector/wire somewhere too....

Tazza, thanks for the answer. I already checked the wires from the sensor to the BOSS unit yesterday.
I had a little bit time after work today and removed the sensor. When i short the wires, BOSS no longer shows AF6 so the sensor switch has to be closed when engine is off. (As shown in the schematics).
Will try to get a new one tomorrow, lets hope that it is not to expensive. (They charged $30 for the spring at the steering spool only)

 

[Tazza]

Tazza, thanks for the answer. I already checked the wires from the sensor to the BOSS unit yesterday.
I had a little bit time after work today and removed the sensor. When i short the wires, BOSS no longer shows AF6 so the sensor switch has to be closed when engine is off. (As shown in the schematics).
Will try to get a new one tomorrow, lets hope that it is not to expensive. (They charged $30 for the spring at the steering spool only)

The dealer may be exensive, but these are used in trucks too. Visit your local druck shop and they may be able to hook you up with one at a better price. The numbers on the outside should tell them what vaccum they turn off at.
As these switches are common on newer machines, the dealer may charge a good price for them too.

 

[ard]

The dealer may be exensive, but these are used in trucks too. Visit your local druck shop and they may be able to hook you up with one at a better price. The numbers on the outside should tell them what vaccum they turn off at.
As these switches are common on newer machines, the dealer may charge a good price for them too.

Ok, changed the sensor and AF2 and AF6 will no longer been shown. Control valve and steering spools are no longer leaking, however, there is an other oil leak i have to find. Would assume there is something between the engine and the hydro pump. Will check that when i'm back home (2 weeks).

 

[Tazza]

Ok, changed the sensor and AF2 and AF6 will no longer been shown. Control valve and steering spools are no longer leaking, however, there is an other oil leak i have to find. Would assume there is something between the engine and the hydro pump. Will check that when i'm back home (2 weeks).

Good to hear you are slowly getting all the leaks fixed. They can be frustrating to find....

 

[mauro70]

Good to hear you are slowly getting all the leaks fixed. They can be frustrating to find....

Hello, I am looking to see if the seals under the Pintle arm could be replaced without causing the neutral and such to be lost. I purchased a manual, and they only take apart the levers and work on the pump completely outside the machine. It is a BOBCAT s530-

 

[Tazza]

Hello, I am looking to see if the seals under the Pintle arm could be replaced without causing the neutral and such to be lost. I purchased a manual, and they only take apart the levers and work on the pump completely outside the machine. It is a BOBCAT s530-

There is a good chance they will be changed, but not too bad to get back to neutral, as it will have some wear now, may be a good time to adjust it if needed after doing the seals.

 

[[email protected]]

Hello, I am looking to see if the seals under the Pintle arm could be replaced without causing the neutral and such to be lost. I purchased a manual, and they only take apart the levers and work on the pump completely outside the machine. It is a BOBCAT s530-

I have a 2005 S250 and I cannot find the hydraulic spool valves. I am trying to replace the spool seals. Can someone show me the location?

 

[flyerdan]

I have a 2005 S250 and I cannot find the hydraulic spool valves. I am trying to replace the spool seals. Can someone show me the location?

The parts book shows that the pedal linkages go backwards, so the valve should be under the floor just in front of the seat.
If there is an access panel, that would be the first place to look.