SevenCorners
Silver Member
I have heard reference to "dead head the pump" for some time without really understanding what this means. Can someone please enlighten me?
Terminology Question
- Thread starter SevenCorners
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Soundguy
Old Timer
- Joined
- Mar 11, 2002
- Messages
- 51,575
- Location
- Central florida
- Tractor
- RK 55HC,ym1700, NH7610S, Ford 8N, 2N, NAA, 660, 850 x2, 541, 950, 941D, 951, 2000, 3000, 4000, 4600, 5000, 740, IH 'C' 'H', CUB, John Deere 'B', allis 'G', case VAC
Blocked or severly restricted pump output. With a positive displacement pump.. if you block the output.. the oil still goes somewhere.. usually blows a seal out.. or cracks a casting.. rarely it may blow a fitting from a line.. and even more rare may make a line rupture... but the oil does go somewhere. ( or the pump self destructs )...
I've seen oil pumps ( pow streering ) that were coupler driven of the back of other devices.. like gennies.. and the pump deadhead, and have it shear the pump input shaft.. or destroy the lovejoy coupler.. or even destroy the input shaft / gearing the primary load was driven off of.
As it pertains to jinmas.. I've seen quick disconnects added in right after the hyd pump ( for a loader? ).. but before a relief ( super bad design idea.. whether it was practical or convienient or not....)... if that qd comes loose, the pump deadheads. I've heard some people use zip-ties as a 'safety' to prevent the slipped coupler issue.
Before greg hops on me with the 'you don't own a jinma issue': /forums/images/graemlins/grin.gif /forums/images/graemlins/smirk.gif /forums/images/graemlins/wink.gif
When i say heard.. that means 'read'.. as in here.. in this forum.... When i say 'saw'.. I mean as in person, looking at an actual tractor at farmpro dealer, ( I have the brochure from the deal if you want proof I actually was there! /forums/images/graemlins/wink.gif ) where you could see the qd inline directly a few inches from the pump.. looked like a gas can dangling over a fire...
If you want non tractor related hyd reference.. you can research 'head' as it applies to fluid power.
Soundguy
I've seen oil pumps ( pow streering ) that were coupler driven of the back of other devices.. like gennies.. and the pump deadhead, and have it shear the pump input shaft.. or destroy the lovejoy coupler.. or even destroy the input shaft / gearing the primary load was driven off of.
As it pertains to jinmas.. I've seen quick disconnects added in right after the hyd pump ( for a loader? ).. but before a relief ( super bad design idea.. whether it was practical or convienient or not....)... if that qd comes loose, the pump deadheads. I've heard some people use zip-ties as a 'safety' to prevent the slipped coupler issue.
Before greg hops on me with the 'you don't own a jinma issue': /forums/images/graemlins/grin.gif /forums/images/graemlins/smirk.gif /forums/images/graemlins/wink.gif
When i say heard.. that means 'read'.. as in here.. in this forum.... When i say 'saw'.. I mean as in person, looking at an actual tractor at farmpro dealer, ( I have the brochure from the deal if you want proof I actually was there! /forums/images/graemlins/wink.gif ) where you could see the qd inline directly a few inches from the pump.. looked like a gas can dangling over a fire...
If you want non tractor related hyd reference.. you can research 'head' as it applies to fluid power.
Soundguy
SPIKER
Elite Member
hi seven:
dead heading the pump means stopping the flow of liquid OUT of the pump (used here mostly describing the hydraulic pump)
other pumps can handel this OURS can't the pump we have is designed to put out a certain amount of fluid per revolution. say 1 CU inch of voulme per turn of the pump stop the output and the fluid has no where to go this results in damage, becasue fluid does not compress. the results are usually broken pump seals, pump shaft or sheared keyway if you are lucky. most of the time the seals blow out of the pump as the fluid finds SOMEPLACE to go!.. There is a HYDRAULIC QUESTION posted I belive in the general forum above which I went into greater depth. but you should get the gist of it.
Mark M /forums/images/graemlins/smile.gif
dead heading the pump means stopping the flow of liquid OUT of the pump (used here mostly describing the hydraulic pump)
other pumps can handel this OURS can't the pump we have is designed to put out a certain amount of fluid per revolution. say 1 CU inch of voulme per turn of the pump stop the output and the fluid has no where to go this results in damage, becasue fluid does not compress. the results are usually broken pump seals, pump shaft or sheared keyway if you are lucky. most of the time the seals blow out of the pump as the fluid finds SOMEPLACE to go!.. There is a HYDRAULIC QUESTION posted I belive in the general forum above which I went into greater depth. but you should get the gist of it.
Mark M /forums/images/graemlins/smile.gif
OP
SevenCorners
Silver Member
Thanks guys, I zipped tied my QD but never really understood why, it was just a recommendation I picked up here. Now it makes sense.
JohnS
Platinum Member
</font><font color="blue" class="small">( I've heard some people use zip-ties as a 'safety' to prevent the slipped coupler issue.
)</font>
Yep, I use them myself. While it probably provides only limited safety, ie in case vibration or something causes the coupler to pop off, it does provide the focus that you need to pay attention to the couplers. It is very easy to think you have the couplers seated correctly, but they are not. You need to pull vigorously on the ends, to make sure. The ties also prevents someone who is not familiar with the tractor, from inadvertly disconnecting them.
It is one of the design issues that the owner has to be aware of, and prepared to handle. Recommend having a spare pump on hand, or at least the rebuild kit. While some dealers will plumb the fel, past the diverter valve, the QD might still be there.
Tie Wrap Info
)</font>
Yep, I use them myself. While it probably provides only limited safety, ie in case vibration or something causes the coupler to pop off, it does provide the focus that you need to pay attention to the couplers. It is very easy to think you have the couplers seated correctly, but they are not. You need to pull vigorously on the ends, to make sure. The ties also prevents someone who is not familiar with the tractor, from inadvertly disconnecting them.
It is one of the design issues that the owner has to be aware of, and prepared to handle. Recommend having a spare pump on hand, or at least the rebuild kit. While some dealers will plumb the fel, past the diverter valve, the QD might still be there.
Tie Wrap Info
OP
SevenCorners
Silver Member
So what should one do when faced with a scenario from John's link if your tractor does not have a decompression handle?
Soundguy
Old Timer
- Joined
- Mar 11, 2002
- Messages
- 51,575
- Location
- Central florida
- Tractor
- RK 55HC,ym1700, NH7610S, Ford 8N, 2N, NAA, 660, 850 x2, 541, 950, 941D, 951, 2000, 3000, 4000, 4600, 5000, 740, IH 'C' 'H', CUB, John Deere 'B', allis 'G', case VAC
I had always thought if I had bouhgt a unit like that that I would re-plumb it.. so that the qd was after the output. Whether this involved a new hose.. or a new hose and and extra relief valve.. even if the extra relief simply dumped the oil straight out on the ground in the case of a deadhead scenerio.. seems like cheap insurance for a known issue.
Next to that.. securing it like you folks do/mention, with the zip ties sounds like the next best bet.
Soundguy
Next to that.. securing it like you folks do/mention, with the zip ties sounds like the next best bet.
Soundguy
JohnS
Platinum Member
Out of a number of people that I have heard about, having blown pumps, he was the only one to have that dieseling issue. If you don't have a decompression lever, not sure what you do. In this case, removing the fuel source, could be a bit un-nerving, ie draining the crankcase while engine running /forums/images/graemlins/crazy.gif
Boltonpower
Silver Member
Hi there,,
When I order single pump tractors like the 204 and 284 I
have the factory plumb the loader supply out of the steering
diverter valve waste port. If you pop the QD the steering gets
a little strange but nothing is damaged. For the life of me I don't
know why the factory default is direct from the pump.
Never been able to figure that out.
Regards
Graham
Bolton Power
When I order single pump tractors like the 204 and 284 I
have the factory plumb the loader supply out of the steering
diverter valve waste port. If you pop the QD the steering gets
a little strange but nothing is damaged. For the life of me I don't
know why the factory default is direct from the pump.
Never been able to figure that out.
Regards
Graham
Bolton Power