Hydraulic pressure D47U with No 44 hydraulic

I just found in the #44 parts book that the operating pressure is 1,000 for a D4 and the bypass is set at 1,200 PSI, so I should be ok with the less expensive hose selection but I didn't know if anyone knew of a situation where the pressure could spike a lot higher.

i think it is possible to create a sudden pressure situation by getting the blade in a bind but i think the 7200 burst pressure would work just fine.

the working pressure of these old girls is max 1200psi for the type 44 hydro unit. SAE 100RT2 2 wire hose is the correct hose for the field fit SAE code61 fittings. note if you get new hoses made with crimp on fittings you have to recycle the original 2 bolt flanges as the current stuff is 4 bolt 2 piece the only difference is the flange all dimensions are the same.

the hoses on a d4 are dash-12 which is 3/4. a dash is equal to a 16th of a inch for hydraulic fittings.

also fit new grade 8 high tensile bolts with nyloc nuts to the hose clamps when replacing the hose. dont let anyone tell you the field fit stuff isnt suitable they are not working at 5000psi like the modern machines.

it is a good idea to use hose burst sleeve or spiral wrap to protect the hoses from wear.

i picked up a 10metre roll of 100R2 for Aud$110 plus post

As usual, you guys came through and I thank you! Aeroquip makes new adaptors that go from type 61 to JIC. I reused the original flanges and they seem to work well. Now I have a much easier to replace JIC hose. My hose ends were getting pretty rusty and a couple were bent, so this seemed a good option for me. It is not original, but this machine will never go to a show anyway. Thanks again!

Elton

some of them are supposed to be bent to allow the hose to work. or were yours bent more than the 37degrees there supposed to be. but yes adapting to jic isnt a bad idea. original who cares. most machines are not original. actually all machines have been modified from factory many with genuine accessories cat in the early years never made blades, winches and other attachments. these were made by LeTournue, laplante choate and hyster for cat machines

Trainkid88, a couple of my ends were bent to the point of crimping. I am using 45 degree adaptors on the valve side and straight adaptors on the cylinders which are close to the original in application. I am now trying to decide the hose length I need. Thanks for your input. Elton

I want to say my hoses were cut to either 30 or 36". I don't have the tractor handy to measure them unfortunately but I can ask my buddy if he could walk over and get a measurement tonight