I thought I might mention this as it might help others. I would have LOVED to have had some of this information weeks ago when one of my lift cylinders started making squishy sounds and peeing all over the floor.
My lift is an XPR-10XC purchased and installed by me in 2009. In its defense, it's been great and I've basically done nothing to it from 2009 to 2024. It also doesn't see the traffic of a busy commercial shop.
When I discovered the leak, I also found that the gland nut on that cylinder was unthreaded by at least several turns. In speaking with a tech guy at carliftparts.com, he said this is not uncommon and is one of the things he looks for when conducting inspections on BP lifts. He said he's not sure exactly why it happens.
I'm also not sure it had anything to do with my failure. It might have allowed the piston to travel too close to the gland nut threads and damage the u-cup seal, but I'm not convinced this was possible with the amount it was unthreaded.
Carliftparts insists all BP cylinders will have a blue, yellow or red band painted around them at some point on the body. Well, mine had no color band of any kind. I wound up ordering a BendPak "universal" kit from them, which I think they just made up because they were baffled that I had no color band. It was $100 and I wound up using exactly ONE thing from it, but I need my lift.
Once I got it apart the problem was at least evident:
The damaged u-cup seal was labeled as 40.8 50.8 6. It's no leap to assume that's metric but the ID makes little sense at 1.606", while the OD makes perfect sense at exactly 2". The seal measured more like 17/64" high but hey, 6mm is close enough.
I dug through the assortment of seals in my "universal" kit and was faced with a blue one that was labeled as 40 50 6. Hmm, ok, kinda close.
Or I had a white one labeled 1.62 1.87 6.
The seals had to rest in a groove measuring 1.619" so the blue 40mm would be tight while the white 1-5/8" would be a touch loose. Despite being labeled as 1-7/8" OD the white seal ultimately measured 2" on the OD at its "flared" lip, so I opted for this.
I also think u-cup seals are supposed to be able to spin a little once installed based upon a wacky Chinese video I watched, so I liked the slightly larger ID of the white seal for my piston (1‐5/8" on a 1.619" minor dia)
I tried way too hard to make a fancy sleeve to install the u-cup seal and my plan even involved an exhaust pipe spreader ("NOT A JOKE!") but after wasting too much of my life I went caveman with boiling water and carefully levered the seal into place.
I had purchased this JIC plug set and that was awesome to plug the line while working on the cylinder. My BP used JIC 4 and because my projects always fight me, I got to learn that #4 uses 7/16-20 threads which I had to chase (not the fault of the plug kit)
I initially could NOT get the piston to move when I got the cylinder on my bench, but putting a little air into the bleeder took care of that. Be careful!!
Upon completion the lift handled my 2007 F150 fine, so I'm cautiously optimistic it's ok despite my prior lack of hydraulic cylinder knowledge.
I deemed my wiper seal to be in good condition so left it alone. I did not like any of the wear bands provided so reused the existing wear band. I have no idea if I'll regret that choice.
If others have experiences with lift cylinders that may help people in the future, please post up
My lift is an XPR-10XC purchased and installed by me in 2009. In its defense, it's been great and I've basically done nothing to it from 2009 to 2024. It also doesn't see the traffic of a busy commercial shop.
When I discovered the leak, I also found that the gland nut on that cylinder was unthreaded by at least several turns. In speaking with a tech guy at carliftparts.com, he said this is not uncommon and is one of the things he looks for when conducting inspections on BP lifts. He said he's not sure exactly why it happens.
I'm also not sure it had anything to do with my failure. It might have allowed the piston to travel too close to the gland nut threads and damage the u-cup seal, but I'm not convinced this was possible with the amount it was unthreaded.
Carliftparts insists all BP cylinders will have a blue, yellow or red band painted around them at some point on the body. Well, mine had no color band of any kind. I wound up ordering a BendPak "universal" kit from them, which I think they just made up because they were baffled that I had no color band. It was $100 and I wound up using exactly ONE thing from it, but I need my lift.
Once I got it apart the problem was at least evident:
The damaged u-cup seal was labeled as 40.8 50.8 6. It's no leap to assume that's metric but the ID makes little sense at 1.606", while the OD makes perfect sense at exactly 2". The seal measured more like 17/64" high but hey, 6mm is close enough.
I dug through the assortment of seals in my "universal" kit and was faced with a blue one that was labeled as 40 50 6. Hmm, ok, kinda close.
Or I had a white one labeled 1.62 1.87 6.
The seals had to rest in a groove measuring 1.619" so the blue 40mm would be tight while the white 1-5/8" would be a touch loose. Despite being labeled as 1-7/8" OD the white seal ultimately measured 2" on the OD at its "flared" lip, so I opted for this.
I also think u-cup seals are supposed to be able to spin a little once installed based upon a wacky Chinese video I watched, so I liked the slightly larger ID of the white seal for my piston (1‐5/8" on a 1.619" minor dia)
I tried way too hard to make a fancy sleeve to install the u-cup seal and my plan even involved an exhaust pipe spreader ("NOT A JOKE!") but after wasting too much of my life I went caveman with boiling water and carefully levered the seal into place.
I had purchased this JIC plug set and that was awesome to plug the line while working on the cylinder. My BP used JIC 4 and because my projects always fight me, I got to learn that #4 uses 7/16-20 threads which I had to chase (not the fault of the plug kit)
I initially could NOT get the piston to move when I got the cylinder on my bench, but putting a little air into the bleeder took care of that. Be careful!!
Upon completion the lift handled my 2007 F150 fine, so I'm cautiously optimistic it's ok despite my prior lack of hydraulic cylinder knowledge.
I deemed my wiper seal to be in good condition so left it alone. I did not like any of the wear bands provided so reused the existing wear band. I have no idea if I'll regret that choice.
If others have experiences with lift cylinders that may help people in the future, please post up
