# BOSS Plow Hydraulic Pump Problems



## CleanCut217 (Jan 7, 2014)

I have a 8ft Boss RT3 thats about 10 years old. Yesterday it started going slow when it would raise up, but turning side to side was completely fine. Sometimes it would cut out and not do anything, then come back on. When I got back to the shop I checked the fluid and it was low so I filled it up. Also on the way to the shop it quit working and had to drive there with it an inch off the ground. I cant get the pump to turn on anymore. What could be wrong? 

I have checked for a good ground. I have power getting to the pump when I push the buttons on the remote as well as the smart switch. I know that the solenoid is functioning properly. What else can I check. I really hope its not the pump. I think its an electrical issue since it was cutting in and out on me. I have checked to make sure the harnness' are pushed together good and they are. Help!!!!


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## CleanCut217 (Jan 7, 2014)

No one has any clue?


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## plowzilla (Nov 19, 2004)

I read that you checked your harness connection. Take it apart and check all the pins on the plow side. There is a pin that is known for breaking off after the years.


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## CleanCut217 (Jan 7, 2014)

plowzilla;1713666 said:


> I read that you checked your harness connection. Take it apart and check all the pins on the plow side. There is a pin that is known for breaking off after the years.


I actually checked those. Also I sprayed it all out with wd40 to make sure there wasnt any water in there.

Update on the problem. I tapped the motor while pushing one of the buttons and the motor started working again. Still working fine side to side. Barley goes up still. Then I tapped on the coils and it shot up for a second and then slow again.

So NOW, heres my question. Why did the pump completely stop working until I tapped on the motor. Did it just kick out because it couldnt flow the fluid?

Also now that I have pin pointed it down to the coil for the up and down, what do I need to replace and could there be a blockage in there somewhere?


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## plowzilla (Nov 19, 2004)

At ten years old, I can be multiple problems. Here is a troubleshooting guide from Boss:
http://www.bossplow.com/content/servicecenter/documents/rt3_straight_blade_troubleshooting_guide.pdf


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## CleanCut217 (Jan 7, 2014)

I know what the problem is. I am wondering if the solenoid coil that releases the fluid to go up is all one part or if there are multiple parts I need to order and also if there is a screen in there or something that could cause a blockage in fluid.


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## terrapro (Oct 21, 2006)

You "tapped" the motor while hitting the buttons on the controller and it started working and you don't think it's the motor?...


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## maxwellp (Feb 16, 2013)

I would put a motor on it. Take an amp reading on the motor. Take the motor off and look at the brushes.


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## CleanCut217 (Jan 7, 2014)

Yea but it works perfectly fine side to side. I think the motor cut out after trying to push the fluid through when the solenoid wasn't open


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## CleanCut217 (Jan 7, 2014)

maxwellp;1713873 said:


> I would put a motor on it. Take an amp reading on the motor. Take the motor off and look at the brushes.


Is there a write up anywhere on how to do this?


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## plowzilla (Nov 19, 2004)

There is a little screen at the end of the lift valve. Go on the boss website and find the diagram for your hydraulic manifold model to determine which is the lift valve. You should also check to see if the coil over that valve is working properly. Have someone hold a metal object, (wrench) next to the coil. When the lift is pressed, the coil should magnetize and pull the wrench to it. Also check for corrosion under the coil, it will interfere with opening and closing that valve.


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## Herm Witte (Jan 27, 2009)

Side to side will often work well in a failing pump. Suggest you check the draw on the pump motor, clean all screens as suggested above, eliminate elecrical issues by checking the grounds etc. I would not be surprised at all if the pump needs to be replaced. They don't last forever.


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## Quickledo (Jan 8, 2014)

Sounds like the motor brushes are stuck/seized in their holders and won't contact the armature effectively. Either clean and lube (fairly easy) the brushes so they will move/slide freely, or get a new/rebuilt motor. Good Luck.


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## CleanCut217 (Jan 7, 2014)

Thanks for the help guys. I will see what I can get done.


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## CleanCut217 (Jan 7, 2014)

Update... got a new motor and put it on as well as a new solenoid for the up hydraulic. I am still having problems with the plow going up and then it will stop. You then have to sit and tap the up button until it is all the way up. I'm stumped


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## plowzilla (Nov 19, 2004)

CleanCut217;1728244 said:


> Update... got a new motor and put it on as well as a new solenoid for the up hydraulic. I am still having problems with the plow going up and then it will stop. You then have to sit and tap the up button until it is all the way up. I'm stumped


When you say "new solenoid for the up hydraulic" do you mean the coil over the lift valve on the manifold?


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## CleanCut217 (Jan 7, 2014)

plowzilla;1728282 said:


> When you say "new solenoid for the up hydraulic" do you mean the coil over the lift valve on the manifold?


Yes sorry. I replaced the whole solenoid coil. Also the down screen on the coil is clean because I checked that one. And I also checked to make sure I was getting magnetism on the up coil after I installed it. The fluid level is where it should be. If you move the blade side to side, then go down and then up the blade will go half way up and then it will stop and that's when you have to start tapping the button to make it go up the rest of the way. Now if it is up and you let it down and go right back up it won't even budge. If that info helps at all. It seems to me that there is a block in the flow of hydraulic fluid somehow but I have checked the hoses and screens in the up and down coils.


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## zlssefi (Dec 29, 2011)

*grounds*

find the wire that is grounding your up solenoid. make sure it has a clean connection. the fact that your only issue is when going up makes me beleive it may be that. Also take out the up valve and push on the end of it with an allen wrench to make sure it moves as it is supposed to.


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## plowzilla (Nov 19, 2004)

CleanCut217;1728293 said:


> Yes sorry. I replaced the whole solenoid coil. Also the down screen on the coil is clean because I checked that one. And I also checked to make sure I was getting magnetism on the up coil after I installed it. The fluid level is where it should be. If you move the blade side to side, then go down and then up the blade will go half way up and then it will stop and that's when you have to start tapping the button to make it go up the rest of the way. Now if it is up and you let it down and go right back up it won't even budge. If that info helps at all. It seems to me that there is a block in the flow of hydraulic fluid somehow but I have checked the hoses and screens in the up and down coils.


Ok, did you follow the torque specs when retightening the nut on that coil and lift valve? I made that mistake before and wound up squishing the lift valve into itself. It does not take much to do this. I believe the correct torque instructions from Boss was to hand tighten the nut with a 1/4 or 1/2 turn, thats it!


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## CleanCut217 (Jan 7, 2014)

The ground is good on the valve. When you say I could have squished the valve, if I loosen the nut will be it fine again? I'll pull it out and see if it moves like it's supposed to


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## plowzilla (Nov 19, 2004)

CleanCut217;1728399 said:


> The ground is good on the valve. When you say I could have squished the valve, if I loosen the nut will be it fine again? I'll pull it out and see if it moves like it's supposed to


No, you would have to replace it as I did.


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## CleanCut217 (Jan 7, 2014)

Ok so I redid the ground on the up coil. I also tried putting the old solenoid and coil on there since I just kinda replaced it even though I was getting magnetism before. Still same thing happening.


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## plowzilla (Nov 19, 2004)

Did you check the lift valve? That is what gets caved in and fluid cannot get thru properly. I squished mine so bad that it only it would only go side to side.
Also, when you lift the plow and it stops, does the motor still run or does that cut out?


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## CleanCut217 (Jan 7, 2014)

plowzilla;1728815 said:


> Did you check the lift valve? That is what gets caved in and fluid cannot get thru properly. I squished mine so bad that it only it would only go side to side.
> Also, when you lift the plow and it stops, does the motor still run or does that cut out?


I checked the valve with an Allen wrench like said above and it moved fine. When the blade is going up and it stops, the motor is still running


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## Woodenshoe (Oct 30, 2010)

You replaced the motor, but did you replace the pump itself? The pump could be worn out and low on pressure. That would explain why turning works (takes very little pressure for side to side) but it cant lift an 800# plow...


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## CleanCut217 (Jan 7, 2014)

Woodenshoe;1729731 said:


> You replaced the motor, but did you replace the pump itself? The pump could be worn out and low on pressure. That would explain why turning works (takes very little pressure for side to side) but it cant lift an 800# plow...


That is one thing I have yet to do is check the pressure


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## plowzilla (Nov 19, 2004)

CleanCut217;1729873 said:


> That is one thing I have yet to do is check the pressure


When you said you changed the motor, I was under the assumption that you bought the whole hydraulic
Unit. It could very well be the pump then.


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## Woodenshoe (Oct 30, 2010)

plowzilla;1729935 said:


> When you said you changed the motor, I was under the assumption that you bought the whole hydraulic
> Unit. It could very well be the pump then.


Never ass u me. Just makes an a$$ out of u & me!


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## CleanCut217 (Jan 7, 2014)

My brother called boss tech support and they had him unplug a wire off the smart switch and now it works? So the smart switch is bad I guess? Makes no sense to me whatsoever. And they said a ground. Coukd it be the ground on the up coil as well. Even tho I checked that...


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## maxwellp (Feb 16, 2013)

Oh please tell us what wire that is.


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## CleanCut217 (Jan 7, 2014)

maxwellp;1730267 said:


> Oh please tell us what wire that is.


ill figure it out and take a picture as well


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## plowzilla (Nov 19, 2004)

Woodenshoe;1729974 said:


> Never ass u me. Just makes an a$$ out of u & me!


Funny, I remember that from an old Benny Hill episode.


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