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Hydraulic cylinders dump truck.

Willie B

Senior Member
Joined
Jan 2, 2016
Messages
4,039
Location
Mount Tabor VT
Occupation
Electrician
My Heil dump body, probably built 1975 has two stage hydraulic cylinders. The part number is AID or ALD 2039-1
In dumped position it does not leak & would stay up months. In down position it leaks out the breather. I'm of the belief the pressure seals the piston, but when pressure is released, it seeps past the piston.

Hydraulic repair shops are understaffed, overloaded with work. The wait seems forever. Most promising is a shop in next state, a one man shop. He makes promised of "a few weeks turnaround". I think I can handle the rebuild, but a seal kit is at best a maybe.

I googled it, Found a company Allegany York, they offer a kit for Heil cylinders. Surely, there is more than one variety cylinder for Heil dump bodies? Could it be? The seal kit RH-K272-4893Faceless.jpg
 

Old Doug

Senior Member
Joined
Oct 16, 2013
Messages
4,485
Location
Mo
I have good luck just taking the seals to a place that rebuilds cylinders they can match most any thing up.
 

Labparamour

Senior Member
Joined
Sep 6, 2013
Messages
732
Location
Washington
I have good luck just taking the seals to a place that rebuilds cylinders they can match most any thing up.

Agree.
Several hydraulic hose/cylinder shops have helped me with seals and packing for an old Melroe bobcat hoe and a Deere cylinder packing, wiper seals, etc.
 

Tenwheeler

Senior Member
Joined
Dec 15, 2016
Messages
870
Location
Georgia
My Heil dump body, probably built 1975 has two stage hydraulic cylinders. The part number is AID or ALD 2039-1
In dumped position it does not leak & would stay up months. In down position it leaks out the breather. I'm of the belief the pressure seals the piston, but when pressure is released, it seeps past the piston.

Hydraulic repair shops are understaffed, overloaded with work. The wait seems forever. Most promising is a shop in next state, a one man shop. He makes promised of "a few weeks turnaround". I think I can handle the rebuild, but a seal kit is at best a maybe.

I googled it, Found a company Allegany York, they offer a kit for Heil cylinders. Surely, there is more than one variety cylinder for Heil dump bodies? Could it be? The seal kit RH-K272-4893View attachment 252520
Look into Hercules sealing products and the Red Book. I would take them apart. Measure and order the seals. Hopefully that matches your part number. No telling if those cylinders were replaced over the years.
 

SoCoHyd

Member
Joined
Oct 29, 2020
Messages
6
Location
Houston
How much oil is leaking out ? unless its a considerable amount, I wouldn't even worry about it. if you think it's just the bleeder then remove the bleeder and change it out. no need to pull the cylinder and have it resealed because of a bleeder. But considering you said that it doesn't leak down at all when in the up position then it's most likely not the bleeder.
you might just be confusing oil accumulation on the rods and caps as an oil leak from the bleeder. Telescopic cylinders allow for a film of oil to accumulate.
of course I can't confirm this without seeing it
but for some piece of mind here is a quote from a reference guide on telescopic cylinders provided by Hercules Sealing Products

"A damp to light film of oil on each plunger or stage of a telescopic cylinder indicates good cylinder operation. After many cycles of the cylinder, a small accumulation of oil may be noticed on the plungers or sleeves at the head nuts. This should not be mistaken for packing leakage. Cylinder should be free of entrapped air. It is advisable to bleed air from cylinder weekly for a smooth operation."

this quote, along with other information, can be found @ this link. click on the "Technical Information" tab which will open a PDF and it will be on page 7 of the PDF (page number of the article will say 559) https://www.herculesus.com/page.php?name=Reference-Guides&id=306

here's the direct link to the PDF although im not sure if this link will work. chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/viewer.html?pdfurl=https%3A%2F%2Fwww.herculesus.com%2Foracle%2Ffiles%2Freference-charts%2FTech.pdf&clen=845279&chunk=true
 

SoCoHyd

Member
Joined
Oct 29, 2020
Messages
6
Location
Houston
If you still feel like your cylinder needs to be taken to a shop to be resealed be wary of what they will charge you for reseal/repair. I wouldn't pay more than $1000 to repair a 2 stage telescopic cylinder.
If its a generic cylinder with no extra features you can most likely buy it brand new anywhere from $1200-$1800

here are some options. https://www.baileyhydraulics.com/pr...escopic?order=onlinecustomerprice:asc&show=48
 

Willie B

Senior Member
Joined
Jan 2, 2016
Messages
4,039
Location
Mount Tabor VT
Occupation
Electrician
How much oil is leaking out ? unless its a considerable amount, I wouldn't even worry about it. if you think it's just the bleeder then remove the bleeder and change it out. no need to pull the cylinder and have it resealed because of a bleeder. But considering you said that it doesn't leak down at all when in the up position then it's most likely not the bleeder.
you might just be confusing oil accumulation on the rods and caps as an oil leak from the bleeder. Telescopic cylinders allow for a film of oil to accumulate.
of course I can't confirm this without seeing it
but for some piece of mind here is a quote from a reference guide on telescopic cylinders provided by Hercules Sealing Products

"A damp to light film of oil on each plunger or stage of a telescopic cylinder indicates good cylinder operation. After many cycles of the cylinder, a small accumulation of oil may be noticed on the plungers or sleeves at the head nuts. This should not be mistaken for packing leakage. Cylinder should be free of entrapped air. It is advisable to bleed air from cylinder weekly for a smooth operation."

this quote, along with other information, can be found @ this link. click on the "Technical Information" tab which will open a PDF and it will be on page 7 of the PDF (page number of the article will say 559) https://www.herculesus.com/page.php?name=Reference-Guides&id=306

here's the direct link to the PDF although im not sure if this link will work. chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/viewer.html?pdfurl=https%3A%2F%2Fwww.herculesus.com%2Foracle%2Ffiles%2Freference-charts%2FTech.pdf&clen=845279&chunk=true
Leakage is perhaps a pint from each after being dumped. I generally leave it parked body up to drain rain or melting snow. No leakage. Leakage happens body down at rest. When I tow, I can't raise the body, so it leaks.

The above mentioned seal kits are described as being for Heil cylinders. I'm perplexed at a kit so non specific.

How does one bleed air from a cylinder? How does air get in? I expect air above the piston, but below is perplexing.

No, the site wouldn't open.
 

SoCoHyd

Member
Joined
Oct 29, 2020
Messages
6
Location
Houston
Leakage is perhaps a pint from each after being dumped. I generally leave it parked body up to drain rain or melting snow. No leakage. Leakage happens body down at rest. When I tow, I can't raise the body, so it leaks.

The above mentioned seal kits are described as being for Heil cylinders. I'm perplexed at a kit so non specific.

How does one bleed air from a cylinder? How does air get in? I expect air above the piston, but below is perplexing.

No, the site wouldn't open.

oh well that definitely sounds like a leak and not just a "light film of oil" haha.
I'm pretty sure that cylinder part number you gave that starts with "2" indicates it's the "old style" Heil telescopic cylinder which means this cylinder is going to have "vee packing." Vee packing reacts to pressure so you're right on the money when you were talking about leakage when pressure is released.
Before you pull the cylinders you might try tightening the 2 gland caps with a pipe wrench and run it up and down a few times. If that doesn't work then pull the cylinders and do the reseals

Air can get in these telescopic cylinder from the negative pressure they produce when retracting as well as when they are being installed after a reseal. It should have a breather at the rod eye. it will most likely be a bolt that you would loosen until oil starts coming out.
 

SoCoHyd

Member
Joined
Oct 29, 2020
Messages
6
Location
Houston
Leakage is perhaps a pint from each after being dumped. I generally leave it parked body up to drain rain or melting snow. No leakage. Leakage happens body down at rest. When I tow, I can't raise the body, so it leaks.

The above mentioned seal kits are described as being for Heil cylinders. I'm perplexed at a kit so non specific.

How does one bleed air from a cylinder? How does air get in? I expect air above the piston, but below is perplexing.

No, the site wouldn't open.

Can I ask how you determined that seal kit part number ?
I just took a look at the seal kit number you gave and it shows that the seals in this kit are "u-seals" as opposed to "vee packing"
I don't think Allegheny sell kits for Heil Dump Truck Cylinders. I think the seal kit number you gave is for a telescopic cylinder off a Heil Refuse Truck.
Another reason I think its Vee packing is due to the age of the truck as well as I've found vee packing to be the norm in Dump truck cylinders
I would call Allegheny and make sure the kit is for a dump truck cylinder
If it is Vee Packing
Hercules Sealing products has Heil Vee packing kits
https://www.herculesus.com/product.php?name=Special Heil Telescopic Vee Sets&cat=16530
part number for the 3 -1/4 " stage is "HL26A2039"
part number for the 4" stage is "HL40004X184"

I hope I was able to help and if not good luck !
 

Willie B

Senior Member
Joined
Jan 2, 2016
Messages
4,039
Location
Mount Tabor VT
Occupation
Electrician
Can I ask how you determined that seal kit part number ?
I just took a look at the seal kit number you gave and it shows that the seals in this kit are "u-seals" as opposed to "vee packing"
I don't think Allegheny sell kits for Heil Dump Truck Cylinders. I think the seal kit number you gave is for a telescopic cylinder off a Heil Refuse Truck.
Another reason I think its Vee packing is due to the age of the truck as well as I've found vee packing to be the norm in Dump truck cylinders
I would call Allegheny and make sure the kit is for a dump truck cylinder
If it is Vee Packing
Hercules Sealing products has Heil Vee packing kits
https://www.herculesus.com/product.php?name=Special Heil Telescopic Vee Sets&cat=16530
part number for the 3 -1/4 " stage is "HL26A2039"
part number for the 4" stage is "HL40004X184"

I hope I was able to help and if not good luck !
Thank you so much for your contributions. The Allegheny website brings up this part number when I googled the cylinder part number. I'm not convinced these will fit. Website says $190 per, but I Emailed them, she says $80 per.
 

materthegreater

Senior Member
Joined
Jul 25, 2012
Messages
642
Location
VT
Willie, how did this turn out?

In testing my dump hinges today, I discovered that the "not leaking" used cylinder I bought leaks oil out almost as fast as the pump can get it in there. So it looks like I'll be tearing the cylinder apart and trying to find the problem.
 

Willie B

Senior Member
Joined
Jan 2, 2016
Messages
4,039
Location
Mount Tabor VT
Occupation
Electrician
Willie, how did this turn out?

In testing my dump hinges today, I discovered that the "not leaking" used cylinder I bought leaks oil out almost as fast as the pump can get it in there. So it looks like I'll be tearing the cylinder apart and trying to find the problem.
The valve used is not the detent style that locks in the down position. Put a bungee cord on the handle to hold it in down position. It no longer leaks.
 

56wrench

Senior Member
Joined
Dec 4, 2016
Messages
2,074
Location
alberta
I never store a truck with the hoist in the raised position because it exposes the cylinder to dust, rain etc. i only raise it about 1 or 2 feet, enough to let moisture drain out of the box. Dirt and moisture can work their way through the wiper as it is lowered as well as the upper stage/stages can rust if left exposed if the wiper is doing its job
 
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