I change from 4-1 to power tiller or grapple or etc many times during jobs... Quick connects are hot and I can not push in by hand to release. I have methods which include breaking loose a connector and bleeding the pressure off and/or a ratchet strap to pull it in. Is this normal? I believe the connectors bleed off pressure once you push them in so far, they will pop when they bleed off pressure into the case drain. It seems to be associated with the rise in temperature of the oil. Any ideas?
If it is a direct hydraulic machine ,shut machine off work controls. Electric control shut off machine ,turn key on work controls.this doesn’t always work . Get punch that fits into female end of connectors,put punch in connector wrap with rag wack with hammer. Male end connector ,wrap with rag push end against something Always use safety glasses and wrap with rag because oil will be coming out under pressure.
It is related to the sun heating the oil in the attachments lines and expanding the fluid, this puts pressure on the couplers. I usually just loosen the couplers of the attachment and let a little fluid out, problem solved. I usually try to unhook the attachment in a shady spot, but that isn't always possible.
What machine model?
T300 .... I am getting that this is a common flaw of Bobcat .... so I will continue my fix ... this is modify # 3 ... it seems I need about 16 inches of leverage to overcome the pressures blocking the connection. It also worked with a ratchet strap. this should prove to be less awkward. I change attachments many times in the jobs I do and that makes it a big issue with me.
Tee a ball valve into each line to release the pressure. Parker and other hydraulic company's sell ball valves for up to 6000 psi. Do an internet search for High pressure ball valve . They are on EBay for about $40.00. You can put a safety plug in it to prevent accidental loss of oil.
Firstly, I'm certain that you understand how the 4db4fh works, but I've attached a video, just in case. In the simplest terms, the machine side, by design, can never be hard to connect.
For residual pressure (or higher) on the attachment side, you need to upgrade your male connector to something like this (Holmbury isn't only one).
There are actually tools made for this problem similar to your homebrew fitting grabber I posted links long time ago for some made in germany and there is also one that uses a stanley quick clamp with ends like your steel flat. I'll look for it in a bit. EDIT: I guess it was Irwin tools... https://xboomcoupler.com/QCMate.asp
tinkerer yes on the ball valve to bleed off pressure, I wish bobcat would do it with a solenoid under the hood, and that works for the machine ..but it can be the attachment too.... Heymccall yes I get that about the fluid shooting into the case drain connector, it is a very complex thing, but as the video shows you still have to overcome pressure to get it to blow into the case drain, that can be too difficult at times, its seems to have something to do with fluid temperature. I thought about using a clamp, but where do I store it. I had a rachet idea that worked but I had to climb in and out of cab. ... My home version covered all the issues, I welded a storage place right on the front of the T300, right were I need it. With the 16 inch leverage handle it overcomes the pressure with easy. The connectors can be too hot to handle and oily. I used stainless threaded 1/2 rod so it can stand the weather without seizing up. i also welded a place on the front of the T300 to hang a cheater bar for the Bobtach levers, they can get stubborn too, of course grease fixes them...shame on me...lol.. The engineers should look at a connector that has a manual valve in it. I think the present engineering is flawed.
Well, I has 4 machines with that 4BD4FH manifold on it, and had 6 more. I never has that issue. Sounds to me like you have under lying issue elsewhere. Definitely, you is overlooking something. Case drain plugged, connector in manifold damaged, etc.
heymccall today i had to use my cool tool every time accept once... from a 4-1 to a power tiller and back needed it every time its a hot day the oil was hot both are used constant and heavy ... then i use it on a tilt/rake attachment the oil was cool because i use it very little it does very little. it comes off with easy no help from the tool. So I conclude it works fine. The stubbornness is associated with the heavy use and hot oil. light use is not a problem and it works like it should.