# Hydraulic filter blowing off



## tccoyle (Nov 6, 2006)

hello out there,
I recently got an old Telelect Digger/Derrick. I was told that we can't use the lift in the winter because the filter blows off and dumps all the fluid due to the cold weather. Anybody else out there have a similar problem or know a fix? Is the by-pass suppose to take care of the high pressure? 
Pretty sure it has the cold weather Hydraulic fluid.
Chris


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## John464 (Nov 6, 2006)

cant help you on the filter.... but curious to know how you apply a Derrick Digger to tree work?


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## tccoyle (Nov 6, 2006)

*bucket truck*

Its a bucket truck...I used the proper name off the repair manual in case someone out there had one.
Chris


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## ASEMASTER (Nov 6, 2006)

BE SURE OF THE PROPER WEIGHT HYD. FLUID AND THE RIGHT FILTER , IT SHoUlD NOT BLOW OFF DOWN TO -30, IF YOU USE IT BELOW THAT TRY A HEATER ON THE TANK FIRST (NO NEED TO WORK BELOW THAT TEMP)
sorry forgot the cap lock on.


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## jonseredbred (Nov 6, 2006)

make sure the filter is on the return line of hydro system, not pressure side.

if it is on the return line, check for blockage between filter and tank. check cap and make sure it is a breather type. make sure tank is able to accept flow,(not chuck full with a tight cap)


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## tccoyle (Nov 6, 2006)

*Thanks*

Thanks for the in-put. I agree that -30 is too cold to be out in workin.
Chris


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## CylinderService (Nov 7, 2006)

Chris,
Sounds like it needs a bigger filter assembly (larger ports). When it's coming down, your lift cylinder may push more GPM than your pump. And with cold, thicker oil, the return line from the filter to the tank may back up more pressure than the filter can take (usually 200-300 PSI). Filter heads usually have a relief, but it won't help if there's too much backpressure from the outlet line. Let me know if we can help. 

Don the Hydraulics Guy


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## Bigstumps (Nov 12, 2006)

Make sure the filter head is on correctly. There is an in and an out. Out towards the tank.


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