Cat 938m P5K01390. Have to reseal this hmu looked on sis for a disassembly/assembly manual didn’t see one for this don’t know if it’s hidden or just none. My question is does this have to be timed.
Call me a idiot what are refering to as a hmu?
Hand metering unit/ steering metering pump. Im pretty sure it has to be timed or the steering will take off. Just having a hard job finding an exploded diagram or disassembly section for that.
I've always known them as HMU's also. No D&A procedure anywhere that I can see. Only specifications and they dont show much. Yes it will definitely have to be timed when reassembled. The only parts I see fopr it is a seal kit 257-8471. I reckon that means they don't want people messing with it. No Reman either which is a bummer.
An interesting snippet for you. As a result of liability concerns from incorrectly assembled HMUs (the timing issue you asked about earlier) instructions for repair of HMUs were removed from the system some time back and it was decided to make them non-serviceable. I wouldn't mind betting even that seal kit I mentioned above is no longer available.
I did get the seal kit from cat a whopping 66$ haha. It’s a char-Lynn Eaton so I did find it from them.
Well at least you got the seal kit which is half the battle. All you have to do now is rebuild the HMU correctly so that it doesn’t break someone’s wrists the first time the machine is fired up.
That is correct
If anyone runs into this issue you can find all the service information/parts/timing procedures you need at www.midweststeering.com if cat eventually stops selling the seal kit you could purchase from a char-Lynn eaton /danfoss dealer.
As I recall, the timing had to do with the position of the gerotor in relation to the springs. If you are careful when you remove the top plate and don’t spill the shaft and everything all out at once, you can take a photo of that relationship for reassembly. I have also learned the hard way to only touch the outside of the steering wheel and be ready at the key if the wheel takes off.
good to see you back John