302.7d solenoid problem

[Catjoy]

Ordered part number 3860880 $744 non returnable/no warranty from CAT solenoid and before I put it on, I’m looking for some advice. What causes a solenoid to fail? I don’t want to put it on and it fail in 20 minutes because there is really another underlying problem.
“Replacement pressure relief solenoid for main control valve assembly that directs main pump oil for main functions of Cat machine” is the description…all I know is that my hydraulics quit working. It seems to go to the the blade controls and the fast/slow driving speed. Cat 302.7d. Any advice, appreciated.

 

[uffex]

Hi
The common cause of solenoid break down is that the winding circuit has a break, not so common maybe vibration & heat contribute. You can check out the windings easily with a multimeter I guess according to your photo's it is a little late for that.
Kind regards
Uffex

 

[heymccall]

Well, you definitely NOW have a bad solenoid.

As suggested above, most solenoid failures are electrical, in that the windings either break or melt together.

I'm a little slow here, so, maybe you could tell me why you focused on this part initially?

If ALL hydraulics quit, I'd think open pilot solenoid or broken pump coupling.
I'm a little rusty on Cat minis, but, IIRC, the blade is typically run off a gear pump and everything else is from the main pump(s).

 

[mikemcc]

15/01/24. Hello Catjoy. I got exactly the same problem.
Did you get it resolved?

 

[007]

There is a lot of reasons the coil will fail and it is usually heat which causes the coil to swell and expand and often breaks the coil wire some where internally causing an open circuit or short.
If the slightest spec of debris gets caught between the internal plunger and the S/S sleeve can cause the internal plug not to travel all the way up inside the coil magnetic field when energized.
This causes excess current to be drawn by the coil and over heats it.
Since it sounds that you have purchased the complete solenoid that resolves that possibility.
Under voltage when energized can cause a week magnetic field and cause the same problem.
Checking the new unit with a multi meter should resolve any issues like that.

 

[Nige]

15/01/24. Hello Catjoy. I got exactly the same problem.
Did you get it resolved?

As he hasn't been on the site for over a year, and never responded to questions from others who were trying to help (see above) my suggestion would be to start again from scratch.

Describe the problem you have on your machine and any information that might be relevant regarding how it started. Throw in a Serial Number as well and I'm sure someone will try to help you.