a hydraulics question.
Thread Starter
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i ain't rite
Joined: Mar 2005
Posts: 65,449
Likes: 5,518
From: Marlboro Mental Hospital.
a hydraulics question.
on the OLD F-350 flatbed dump i just picked up, the body did not work.
so i put 3 gallons of hydraulic oil in the tank, and after the pump primed, the body went up a bit.
this thing has 2 pistons, one on each side of the frame.
i cycled it a few times, but the only way to get it down is to put weight on the headboard.
it will go up on both sides to the second section of the piston, but the driver side stops at the second stage, and the body starts to twist as the passenger side keeps extending.
does this sound like a stuck piston, or just an air bound system???
all my large trucks have single pistons with air bleeder screws on the top of them.
i have not been able to find any bleeders on these small pistons yet, though i have not looked very hard.
so i put 3 gallons of hydraulic oil in the tank, and after the pump primed, the body went up a bit.
this thing has 2 pistons, one on each side of the frame.
i cycled it a few times, but the only way to get it down is to put weight on the headboard.
it will go up on both sides to the second section of the piston, but the driver side stops at the second stage, and the body starts to twist as the passenger side keeps extending.
does this sound like a stuck piston, or just an air bound system???
all my large trucks have single pistons with air bleeder screws on the top of them.
i have not been able to find any bleeders on these small pistons yet, though i have not looked very hard.
Fleet Owner
Joined: Jul 2006
Posts: 20,347
Likes: 802
From: Mi'kma'ki
try cracking the line on the piston that doesn't want to keep going up.this may bleed it?
i had this trouble last year,and it was water in the system-the truck burned and melted the cap on the pump,and let water in.this was from the truck i got the dump from.
i took the pump inside and let it thaw out overnight.
naturally i flushed my system good when i saw it started working.the old trans fluid was very light pink due to all the water in it!
on a twin ram setup like this.is there some type of proportioning valve that provides each ram with the same amount of pressure?
edit,
i also remember it took mine a good 10 times up and down to fully prime good.it wouldn't go up all the way.your supposed to only go up a little ways and back down,and then progressively go higher,longer as i recall.for twins i wouldn't be surprised to take more.
i had this trouble last year,and it was water in the system-the truck burned and melted the cap on the pump,and let water in.this was from the truck i got the dump from.
i took the pump inside and let it thaw out overnight.
naturally i flushed my system good when i saw it started working.the old trans fluid was very light pink due to all the water in it!
on a twin ram setup like this.is there some type of proportioning valve that provides each ram with the same amount of pressure?
edit,
i also remember it took mine a good 10 times up and down to fully prime good.it wouldn't go up all the way.your supposed to only go up a little ways and back down,and then progressively go higher,longer as i recall.for twins i wouldn't be surprised to take more.
Thread Starter
|
i ain't rite
Joined: Mar 2005
Posts: 65,449
Likes: 5,518
From: Marlboro Mental Hospital.
the pump was dry, and the tank was empty. the pump has a single outlet, that is split into two hoses, one going to each piston.
i was thinking of switching sides with the hoses to see if it was a bad hose.
i figure if it is a bad hose, the problem will switch sides.
the thing of it is, i do not know when if ever the last time this dump assembly was used.
i know it worked in 82 when it was put on the truck, but i am not sure if it was ever used since them.
i was thinking of switching sides with the hoses to see if it was a bad hose.
i figure if it is a bad hose, the problem will switch sides.
the thing of it is, i do not know when if ever the last time this dump assembly was used.
i know it worked in 82 when it was put on the truck, but i am not sure if it was ever used since them.
Post Fiend
Joined: Nov 2003
Posts: 21,285
Likes: 15
From: Nutter Fort, WV
Grease the crap out of all the pivot points.
My guess is you have some rust in them binding up the bed/hoist.
Weight on the head board to get the bed down is what makes me think that.
As for the twisting, probably the same binding piviot points causing that.
Just keep working it up and down, add a bit more grease, more up and down till it free's up.
My guess is you have some rust in them binding up the bed/hoist.
Weight on the head board to get the bed down is what makes me think that.
As for the twisting, probably the same binding piviot points causing that.
Just keep working it up and down, add a bit more grease, more up and down till it free's up.
