Hi All, I'm hoping someone can help me out. Recently purchased a SN 495A304CB Clark 75C w/ Detroit Diesel 4 - 71 Turbo. We were able to run the machine for a bit both forward and reverse no problem. After sitting for three months it will only move in reverse. Trans fluid is registering full on the sight glass, brakes release. When shiffting into "F", there is no sound at all as if nothing is engageing. Any help would be greatly appreciated. Thanks!
HeavyEquipmentForums HeavyEquipmentForums Greyson
Question Thanks for the help on this. If I have reverse, would that not indicate that the pump and converter are working correctly? Could the problem be with the lingage or transmission valve?
If it still pulls well in reverse, you probably don't have a pump issue. You're going to need a pressure gauge to check engagement circuits. I can't tell you where the ports are on that machine. It sounds like a de-clutch issue, since that feature only acts on the forward control. Greyson
Been a few years since I worked on a Clark transmission but first thing I might check like "gtermini" mentions is he de-clutch valve. I'm not 100% sure if it only works in forward or not but still an easy place to start. I'm attaching a picture that I'm guessing looks like the valve on the side of your transmission where the shift linkage connects. Between the two spools the shift linkage connect is what I believe is your de-clutch valve. On the top where the red arrow is pointing should be a fitting with a hose connected to it, or possibly a metal line. Either way with air pressure up on the loader and engine shut off disconnect this line and see if there is any air pressure coming out. If none, without starting the engine push down on the brake peddle, if two use the left one. There should be air at this line with brakes applied, but none with brakes released. If there is air all the time at this fitting a quick test would be to cap off the line and with it still unhooked from the control valve try moving the loader, it should move. If there is air all the time to this fitting your problem would most likely be sticky brake valve or leaking brake valve. First thing to check is to soak the pivot points on the peddle with penetrating oil. If that doesn't free it up sometimes you just need to remove peddle and valve and clean everything up and reassemble. The brake valve is most likely a common brake valve that any good truck parts shop would sell. If it still doesn't move I would clean off the top of valve and remove the part marked #2. Then lift out the spool marked #10 and spring #11 to make sure the spring is not broke and the spool is free in the bore. You could then disassemble the part marked #2, to make sure every thing in there looks good and moves free. Not sure if you have any books on this machine but here is a link to the parts book I used.: http://www.minnpar.com/partbooks/WHEEL%20LOADER%20MANUALS/MICHIGAN%20VME%20WHEEL%20LOADER%20MANUALS/75C%20%233260.pdf
Gtermini & Kshansen A huge Thank You!
Im new here ! We have a clark 75b no forward and reverse also! . Any tips or idea how to solve this problem .?.
This is an old thread. Please start a new one. Please include make model and serial numbers with a good description of the problem in your post and I’m sure some of the great people on here will be able to steer you in the right direction.