r/Hydraulics

Hi, looking for some advice! Got to replace this hose, can’t get a regular 19mm spanner into the gap to remove old hose.
Is there any tool that could be recommended?

Hello everyone. Im having an issue with a bobcat e45 mini ex where it has slow hydraulic functions until it warms up. Super slow in the winter time. It has a variable displacement piston pump. Ive only had the chance to look at it once when it was cold. First thing I did was check pilot pressure and it was in spec and didnt drop when using the all the different functions. Then i hooked the gauge to the main valve and dead headed all the functions to check the circuit releifs and they were all in spec. Machine was moving incredibly slow while doing all this. I dont have a flow meter but I feel like the pump isnt weak or anything like that. Once it warmed up the functions were moving quick and it still had same amount of power.

Im leaning towards something to do with the load sense circuit, but this is my first time diagnosing any sort of load sense thing so im not exactly sure how it works. I have the manual but it doesnt exactly say how it works either. I think i have an idea how it works, so please tell me if im wrong.

Number 7 on the schematic is the pump. That sends fluid to P1 on the valve block and down to all the spools. When a function is activated, the spool shifts and sends pump pressure to whatever function you activated, but also sends it to number 31. That shifts number 31 spool over and sends fluid into the load sense circuit, and then down to the pump to change the angle of the swashplate in the pump and increase pump output. Is this accurate? Im not exactly sure how number 8, 9, and 10 in the pump work to achieve the swashplate angle change. If theres any videos or literature on this that you think would help, please send it my way. Thank you all in advance.

Added a better picture of the schematic in the comments

Forgive my ignorance. But would it be possible to convert this style of hydraulic press to run with a electric pumo rather than the hand valve? I have a basic understanding of hydraulics but not enough to try and do the conversion without much more information. The plan is to use is as a small forging press, in its hand pump function its rated for 10tons but i cannot find information on the ram specifications and im away from the one i have to measure it. Im not sure if because it only has one port it would even work or if i would have to aquire a different ram. Any help is appreciated.

I'm starting to sell these fittings and i dont know much about them. To my surprise when i got them, they came without the orings, is this standard practice? Also what do you guys prefer, do you think im better to pre install them on the fittings or should i send them on the side. Im selling to hydraulic shops or anyone that assembles hoses.

Thank you for your input

Hello. I have a hydraulic power unit. I am trying to make it work. How do you wire up this remote up and down please? Included are a couple photos of the solenoid directional I am trying to mate it with. Thanks for any and all information.

This is twice with the same skidsteer "tree puller" implement. This is the low-flow hydraulic fitting on my Kubota SLV75. The first time it happened I was worried about it being a banged up male end (bought the tree puller used), so I replaced that too.

The device is nothing more than a single piston for moving one arm of the scissors.

I'm hoping that the answer is "pulling too hard on the line" because then I can just get a longer hose or be more careful. I'm not sure what else it could be.

I'm interested in an expert's opinion.

Hello and thanks for any help. I've got an older craftsman 3.5 ton floor jack. I recently drained the jack oil, refilled and bled it. It seems to be working fine in the little bit I've used it since. 

The thing I'm wondering about is the release valve. It seems to wobble a bit as it travels up and down. As in I can see that the center of the star gear doesn't stay centered as the release valve goes up and down thru its travel.

Not sure if it has always been this way or if I somehow caused this while I was draining and filling the oil. I didn't really use this jack much and it's been a while since I used it last so it is possible it's always been like this. But should it be? Maybe I never noticed it before and I'm only noticing it now after poking around and working on the unit.

Should the release valve be seated such that the star gear will stay centered thru its travel? There's not too much wobble, maybe a couple millimeter worth of difference measured at the center 

It is enough play that as I spin the handle to tighten/loosen the release valve I notice a difference in engagement between the two stars of the universal joint. I can feel a tight spot where the star gear of the release valve strays far enough from center that it slightly binds against the star gear of the handle.

So, wondering if that play/wobble in the release valve is normal. The jack does operate well enough to use normally. Just annoying to feel that slight binding.

Thanks for your time. 🤙

Hi

I am looking for failure modes that would allow more oil than necessary to pass through a flow control valave. So far l have:

1. The valve/orifice failed open and allows more oil to pass through

2. The check valve stuck in open position due to contamination or some other reason.

My question: Did l miss anything?

My question applies to both a catridge type and an inline type of flow control valve

Hi! I’m trying to identify a reusable hydraulic hose fitting that was used on a transmission cooler line on a car over 20 years ago!

Here are the details I have:
● The fitting appears to be a two-piece field-attachable (reusable) hose end rather than a crimp fitting.
● The male thread measures approximately 9/16-18.
● The nose has a tapered sealing cone, but I’m trying to determine whether it’s JIC 37°, SAE 45°, or another sealing standard.
● The fitting has been on the vehicle for years, so I don’t know the original manufacturer.
● Several people have referred to it as a “Strat” or “Stratoflex” fitting, but I’m not sure whether they’re referring to the brand or just using shop slang for a reusable field-repair fitting.
My questions are:
1. Based on the photos, can anyone identify the manufacturer or fitting family (Parker/Stratoflex, Aeroquip, Weatherhead, Gates, etc.)?
2. Does the nose geometry look like a JIC 37° flare, SAE 45° flare, or something else?
3. Is there a reliable way to distinguish these reusable hose ends by their machining features or dimensions?

Thank you!

Hello everyone, I have this old Parker valveP/N: D1VW20DNYC5-72 (first picture), the vendor offered the one in the second picture. I have doubts about it because the diagrams are different, but on the Parker catalog, there is a note calling out "spools have closed crossover".

Do you think this is a direct replacement?

Thank you!

https://preview.redd.it/l9v0qbo792ah1.png?width=1600&format=png&auto=webp&s=7aa2a8e469ae5d86dc920cefcc95061989866608

https://preview.redd.it/jf3xmtgea2ah1.png?width=1600&format=png&auto=webp&s=60af612ab0b406d5ddab37c70d1b0648fdd334ef

This is the lifting apparatus for a dam gate for some part of the Hillsborough river, or possibly an extension off of it. They spend a lot of time and money to schedule these down for service outside of hurricane season so they can control flooding all through Tampa and the surrounding areas. I serviced and repaired probably a dozen of these cylinders over about 2 years, I had several custom tools I built to remove these threaded rod ends from these massive clevis. Then there was some internal restructuring and the contract was handed off to another company. The new company came out and you can see their attempts at unthreading the rod from the clevis. I don’t work there anymore, these were forwarded to me by my dad who owns the repair business I worked for.