Hello all im new to the forum and just bought an old 4500 ford backhoe, I think I bought a pig in a poke or maybe just a PIG lol. anyways it seems im in need of some help. The hoe itself is very week the loader buckets works but it too seems week. Is there a place I can check hyd pressure on the pump and I was reading other post pressure should be around 2100psi??? is that right also the p/s is not working ANY HELP would be greatly appreciated
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HarleyOne
- Thread starter Harleyone
- Start date
4500 Ford backhoe
Hello all im new to the forum and just bought an old 4500 ford backhoe, I think I bought a pig in a poke or maybe just a PIG lol. anyways it seems im in need of some help. The hoe itself is very week the loader buckets works but it too seems week. Is there a place I can check hyd pressure on the pump and I was reading other post pressure should be around 2100psi??? is that right also the p/s is not working ANY HELP would be greatly appreciated
Hello all im new to the forum and just bought an old 4500 ford backhoe, I think I bought a pig in a poke or maybe just a PIG lol. anyways it seems im in need of some help. The hoe itself is very week the loader buckets works but it too seems week. Is there a place I can check hyd pressure on the pump and I was reading other post pressure should be around 2100psi??? is that right also the p/s is not working ANY HELP would be greatly appreciated
That sounds right for the pressure. Yes, you can check the hydraulic pressure, but it's not exactly the thing you can explain easily. You could tee into the line safely but that will just tell you that the pressure is low, which you already know because the hydraulics are weak. So either your pump isn't producing enough pressure, or the system is leaking enough to keep it from holding the pressure. If you test the pressure of your pump with the output blocked it can explode, and then you still don't know if it was good or not.
How about this, start the thing up cold, let it run a minute or two, then hold one function "to the relief" for 30 seconds, then shut it off in the same position. So, start it, hold the bucket tilt all the way back for 30 seconds, shut the engine off with the handle still held back, then see if either the hydraulic pump, or any part of the control valve are warmer to the touch than the rest.
How about this, start the thing up cold, let it run a minute or two, then hold one function "to the relief" for 30 seconds, then shut it off in the same position. So, start it, hold the bucket tilt all the way back for 30 seconds, shut the engine off with the handle still held back, then see if either the hydraulic pump, or any part of the control valve are warmer to the touch than the rest.
When you hold the bucket tilt back against the stop, either the pump is not pumping, or a relief valve is leaking oil. Either one will heat up if it's the problem. So probably the pump and/or the inlet area of the loader and/or backhoe control valve will get warm. You can always hope at least. Try that once and see what you can see.
kshansen
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The idea is oil flowing through a restriction will cause the heat.
Hope I can word this so it makes sense:
In the pump if it is leaking internally the oil itself is not moving as such but the turning of gears <or what ever type of pump it is> are moving in the stationary oil. So in effect the "restriction" is moving in the oil. Same thing as the oil moving through a restriction. Like they say "all things are relative".
So what ever is getting hot would be the first item to check out. If it was a bad piston seal in a cylinder you could expect the cylinder to get hot near the area of the leak. But assuming this weakness is not just in one circuit a bad piston seal would not be my first guess.
Hope I can word this so it makes sense:
In the pump if it is leaking internally the oil itself is not moving as such but the turning of gears <or what ever type of pump it is> are moving in the stationary oil. So in effect the "restriction" is moving in the oil. Same thing as the oil moving through a restriction. Like they say "all things are relative".
So what ever is getting hot would be the first item to check out. If it was a bad piston seal in a cylinder you could expect the cylinder to get hot near the area of the leak. But assuming this weakness is not just in one circuit a bad piston seal would not be my first guess.
OK well it finely stop raining here in nc so we had a chance to try out the hoe again we started it up let it run for about 5 min pulled back on the bucket til relief and held it there for 30 to 45 seconds and nothing got hot so what did that tell me??
jimg984
Senior Member
check the strainer in hyd fluid tank it will in line leaving tank to hyd pump 4500 where bad about losing packing from hyd cylinders
My first guess would be to check the relief valve(s?), because it's cheaper and easier than a pump.
So the loader and hoe operate at close to reasonable speed with no load, but have no power. That should be a relief valve or the pump, right? Does the engine load up at all when you the cylinder hits the end? Does it do anything different/funny if you use two functions at the same time, like loader and backhoe at the same time.
I don't know fords, just guessing mostly.
So the loader and hoe operate at close to reasonable speed with no load, but have no power. That should be a relief valve or the pump, right? Does the engine load up at all when you the cylinder hits the end? Does it do anything different/funny if you use two functions at the same time, like loader and backhoe at the same time.
I don't know fords, just guessing mostly.