Help with Brush Hog bypass valve.

sawdustmaker · Sep 15, 2016

I have a Brush Hog i need to get running but it will not bypass properly. There appears to have been a spring loaded lever that pushed the bypass valve down but its is no longer there? Is this correct?

sawdustmaker · Sep 15, 2016

I have tried to google image search a picture of what this is supposed to look like with no luck. this is a bobcat brand attachment.

lantraxco · Sep 15, 2016

Little more info? Model of the attachment, or more pictures... "Brush hog" is a pretty generic label for anything from a field mower to a full out forestry mulcher.

Some of the bobcat attachments have a safety shutoff...

Ronsii · Sep 16, 2016

Also any info that is on the valve in the pic would be helpful to determine what it is for and does so you could either activate it or at least bypass it.

hvy 1ton · Sep 16, 2016

It's a crossover relief valve. The relief function should be handled by an internal pressure relief valve set somewhere north of operating pressure. Willie posted this diagram in a similar thread.

https://www.heavyequipmentforums.co...stopping-mower&p=650241&viewfull=1#post650241

If i had to guess i'd say the broken spring? is part of a safety that shuts the mower off when it's lifted off the ground.

sawdustmaker · Sep 16, 2016

I do not see a model tag. It's a 5 foot bush hog. "Brushcat".

Attaching images here is not as simple as it seems

sawdustmaker · Sep 16, 2016

I had not thought about the possibility of it being an "off ground" safety shutoff. I think you are correct about that.
I have been through the whole valve body and cannot find anything that is wrong. It will power up and run like its is supposed to but when you let off the hydraulics is makes a terrible noise from the gear housing. Obviously it is not bypassing properly. i do not see any simple check valve in this housing. To be honest im not sure why this housing is anything more than a check ball besides what hvy 1ton said about it being a off ground safety.

lantraxco · Sep 16, 2016

I don't have access, but yeah the specs say it has a safety shutoff which I would guess that spring is the only thing remaining from the linkage. If you think you might cause damage operating the way it is, wouldn't take much to tee in a check valve or low pressure relief.

sawdustmaker · Sep 16, 2016

I have thought about that. It would be pretty easy.

crewchief888 · Sep 16, 2016

sawdustmaker said:
I had not thought about the possibility of it being an "off ground" safety shutoff. I think you are correct about that.
I have been through the whole valve body and cannot find anything that is wrong. It will power up and run like its is supposed to but when you let off the hydraulics is makes a terrible noise from the gear housing. Obviously it is not bypassing properly. i do not see any simple check valve in this housing. To be honest im not sure why this housing is anything more than a check ball besides what hvy 1ton said about it being a off ground safety.

brushcats have always made noise when the hyd's are shut off, especially at full throttle....

that valve is a safety shutoff that stops hyd flow when the attachment is lifted off the ground. you are missing the lever, pivot bolt/nut/ washers and a chain master link that connects the lever to the spool.

parts are available from bobcat

:drinkup

TriHonu · Sep 16, 2016

Bobcat has their parts diagrams available online at [url]http://bobcatpartsonline.com/bobcat/[/URL]

You must use Internet Explorer and your pop-up blocker must be disabled, or you will not be able to view the diagrams.

In the Model dropdown list, select Rotary Cutter. The next screen will allow you to select a specific model. I saw diagrams that showed a lever attached to the valve.

lantraxco · Sep 16, 2016

TriHonu said:
Bobcat has their parts diagrams available online at [url]http://bobcatpartsonline.com/bobcat/[/URL]

You must use Internet Explorer and your pop-up blocker must be disabled, or you will not be able to view the diagrams.

In the Model dropdown list, select Rotary Cutter. The next screen will allow you to select a specific model. I saw diagrams that showed a lever attached to the valve.

I couldn't get it to work, but it is now, lol... Thanks for the pointers!

Help with Brush Hog bypass valve.

sawdustmaker

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sawdustmaker

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lantraxco

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Ronsii

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hvy 1ton

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sawdustmaker

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sawdustmaker

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lantraxco

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sawdustmaker

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crewchief888

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TriHonu

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lantraxco

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