642 control valve repair

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I just noticed that my control valve was leacking. Is it possible to install new o- rings and seals without taking it out of the machine? What is involved in taking it out of the machine, how long should it take ? Can you get to it from the rear or front?

 

[Tazza]

Depends, where is it leaking? from the end of the spools? is there access behind it for the spool to be removed? Some had hydraulic lines that made it so you couldn't get the spool out without bending it. If you bend a spool its then rubbish, you will need an entire control block then.
Seals can be done without pulling the block if there is nothing in the way, the job is not at all fun, expecially the detent balls..... Very frustrating indeed.

 

[[email protected]]

Depends, where is it leaking? from the end of the spools? is there access behind it for the spool to be removed? Some had hydraulic lines that made it so you couldn't get the spool out without bending it. If you bend a spool its then rubbish, you will need an entire control block then.
Seals can be done without pulling the block if there is nothing in the way, the job is not at all fun, expecially the detent balls..... Very frustrating indeed.

The valve is leaking from the front side toward the seat. I have already messed with the detent balls, not to bad. I can get at the rear part of the valve by taking out tne battery and getting my extended arms out. What happens when I take the spool caps off, I think there called spool caps. Is this where the o- rings or seals go? Never messed with this valve sorry for the ignorance. Just got smoked by a Bobcat dealer and will do all my repairs from now on.

 

[Tazza]

The valve is leaking from the front side toward the seat. I have already messed with the detent balls, not to bad. I can get at the rear part of the valve by taking out tne battery and getting my extended arms out. What happens when I take the spool caps off, I think there called spool caps. Is this where the o- rings or seals go? Never messed with this valve sorry for the ignorance. Just got smoked by a Bobcat dealer and will do all my repairs from now on.

If you can get access, drain as much oil as you can. Remove the allen head bolts and slide the boot off.
Not sure 100% on your control block, some had quad rings that you remove the spool and scoop it out with a seal pick. Some had a steel insert that slid over the spool and held the seal in place, made for easy removal. The ones that are machined into the housing are a little harder to remove, but can be done.
With the cap on the back un-done you can slide the spool out. You technically can just do the front, but if you are that deep, you may as well do both ends, then its right.
Does that make any sense?

 

[cnord]

If you can get access, drain as much oil as you can. Remove the allen head bolts and slide the boot off.
Not sure 100% on your control block, some had quad rings that you remove the spool and scoop it out with a seal pick. Some had a steel insert that slid over the spool and held the seal in place, made for easy removal. The ones that are machined into the housing are a little harder to remove, but can be done.
With the cap on the back un-done you can slide the spool out. You technically can just do the front, but if you are that deep, you may as well do both ends, then its right.
Does that make any sense?

Yeah, the o-rings that set in the block are the funnest to get out. Usually a 90 degree pick will do the trick as long as its small enough. I would highly recommend changing both the front and the back while your in there, because they all have similar ware on them and when you fix one, the other could go bad tomorrow. As always, be clean, incredibly clean. Any dirt that gets in the block or on the spool can and will damage your housing and cause internal leakage, and like said above, big money is needed then.

 

[[email protected]]

Yeah, the o-rings that set in the block are the funnest to get out. Usually a 90 degree pick will do the trick as long as its small enough. I would highly recommend changing both the front and the back while your in there, because they all have similar ware on them and when you fix one, the other could go bad tomorrow. As always, be clean, incredibly clean. Any dirt that gets in the block or on the spool can and will damage your housing and cause internal leakage, and like said above, big money is needed then.

I may have given the wrong name for the valve. Im looking in my shop man. and it just calls it a hydraulic valve ,no metion of control valve. Its the valve that controls the aux. hydros with the three caps toward the back .However its leacking from the spools facing the front of the machine. Is this the same valve that you were speacking of?

 

[skidsteer.ca]

I may have given the wrong name for the valve. Im looking in my shop man. and it just calls it a hydraulic valve ,no metion of control valve. Its the valve that controls the aux. hydros with the three caps toward the back .However its leacking from the spools facing the front of the machine. Is this the same valve that you were speacking of?

Yes that is the same valve they are speaking of.
Ken

 

[bfingar]

Yes that is the same valve they are speaking of.
Ken

Since I believe I need to do the same repair on my 642, are the seals only available through Bobcat or are they available through someone else? Does anyone know the make and model of the spool valves?

 

[Tazza]

Since I believe I need to do the same repair on my 642, are the seals only available through Bobcat or are they available through someone else? Does anyone know the make and model of the spool valves?

You should be able to take the sample seals to a hydraulic seal shop and they can match them for you.

 

[cnord]

You should be able to take the sample seals to a hydraulic seal shop and they can match them for you.

Check with loaderpartssource.com They can rebuild them for a pretty good price.