Gunny65

Yes, this is on the rotating railway dump truck. No, this valve does not control the rotation, it controls the up/down motion of the bed. I don't have a knowledgeable enough local shop that can source this. I am very rural and my options are limited due to driving distances. If at all possible, I need to do this myself. I do have something to safely hold the bed while I work on the valve. I just need a replacement valve since the original maker is out of business.

I cannot find the flow rate for the hydraulic pump that controls the fluid that operates the bed on my: VIN: DM685SX40451 1979 Mack Model: DM685SX 44k Rear Tandem Axel The hydraulic pump description tag that was on the pump is missing. Hopefully, someone knows the flow rate? Thanks.

Thank you Heinz, I contacted that company and am waiting for a reply. I have other hydraulic valve companies I have contacted as well, just no luck YET.

We have the bed supported in the up position. Safety first. The valve has been out already to see if we could fix it. No go. Yep, I have not been able to find a part that would fit but I am not a mechanic and do not know where to go except internet search. That has gotten me close but not quite there. I was hoping someone on here would have a good place to start. I am calling different companies but so far nothing that would fit.

The bed on my dump truck went up, but will not go down. We found the problem but I don't know where to get a replacement. We tried to fix this one but it is done. Attached is a picture of the valve. It has two wires going inside an opening. The two wires move slightly when the valve is actuated. The valve does not actuate far enough to let the bed come down. The item is a Teledyne Republic Part Number: 962-G34D2, 12 volt, 6 watt, 3000 psi electric directional control valve. I found one company that makes one like it but only has it in 110 volts or 24 volts. Any help is appreciated. Thanks.

Yep, I think that is accurate. My color order is the opposite (in actual order) but that sounds correct. I am not towing anything though. The Red is always off/out. If I hit red it sets the other two to off/out. The yellow is on/in for normal operation and the blue doesn't do anything if I push it. While it has the Knob, I think they replaced the trailer lines when they put in the hydraulics and mechanisms for the rail road wheels/axle/etc. I need to look closer but I don't see any glad hands anywhere. There are old stowing spots for the hands but no actual plumbed lines.

I imagine the PO used the rope going through the engine cover as a way to set the basic start up idle where he wanted it. I don't see any other on demand use for it as you can't let loose of the rope and hope it goes back to the starting point since it is pinched as it comes into the cab. I ordered a replacement idle/throttle cable. All the other linkage is there I just may need to clean it up and lube it.

The hand throttle is missing. I found the cable sheath under the dash and followed it to the linkage under the cab. The throttle handle, dash mount and cable are all missing. At least I know what it is now. Thank you.

I have ordered replacement switches. They will be in next week.

Here is what i think is the buzzer box. One of the spades is busted off and there are no wires close to it that have spade connectors. Another shrug.

This on the passenger side of the engine down on the lower end and back of the engine. The rope goes into the cab. I assume to pull on. Anyone know what this is and why anyone would put a rope on it?

I haven't decided what I am going to do with the railroad wheel axles and associated parts. It is a lot of weight but it isn't in my way either. I would like to take it all off at some point. Maybe repurpose the hydraulic cylinders and valves. I also will more than likely never use the turn table for dumping as it would be way off balance and I have no track to hook the stabilizers onto. It would be a bit dangerous I would think. It is cool and all but I really bought the truck simply because it was $1,600 bucks, it ran and it dumped. I put a clutch in it and some work on the electrical and I have an inexpensive dump truck.

Yep, I have three knobs. Emergency, tractor parking, and system parking. I think the system parking is if a trailer is attached. It also has a jake brake (trolly brake, Johnson bar) on the steering wheel post.

I unplugged that switch you saw on the left of my pic. When I did, the low pressure light turned off. I plugged it back in it came back on. I then unplugged the white square looking switch on the right of my picture and the low pressure light came on. I did notice the square switch on the right has 70psi written on it. The switch on the left has no markings at all and looks to be original. Rusty and beat up really. Now that I know where the buzzer is, I am going to see if that has something to do with the buzzer. I am getting closer. Thanks everyone.

THAT!! I have a black box right where you are talking about. It is not connected to anything and I didn't know what it was. Excellent. Thank you. I will take a pic tomorrow. There are not any unconnected wires hanging near the box that I remember seeing but then again, I wasn't fixated on that part. I switched the wires on the new valve I posted a picture of and now the brake lights are not on constantly...however...they do not come on when the brake pedal is pushed, nor at any other time (IE: air pressure at zero, or at full, with parking on or off). The bulbs come on when the running light switch is flipped. At normal brightness now but I just couldn't get the brake lights working, yet. Yep, I expect it to take me a while to figure out the wiring. Lots of wires not connected to anything and lots of wires that are newer that run to headlights, spliced to old wiring, etc. The marker lights do not work. The turn signals do not work (I put in a new flasher unit, no luck there). Right now I just need brake lights and turn signals. I can work the other stuff over time.