Cat 320C Power Shift PRV calibration

[03hdrk]

Read a lot of info on this site and the internet about calibrating the Pressure relief Valve, so I ordered a manual to get the full set of instructions. Waiting for the manual to come in.

My question is - Do I have to have a computer and software to do this calibration, or is it done through the monitor?

BTW - this is all because the machine is slow in all functions.

 

[Cmark]

Done through the monitor, but you will need a pressure gauge with a long hose.

 

[03hdrk]

Thanks for the reply. Got the pressure test gauges and fittings - just need more hose.

 

[03hdrk]

Worked on the machine today. Pressures show to be good. I can go into many details, but I this point I would like to know how to calibrate the Power Shift functions if possible. The manual I bought just tells how to measure and adjust all the pressure relief valves and flow control.

The machine seems to move slow in most or functions when under a load even though the pump is producing a little higher than normal pressure. I noticed today that the boom down function will move about 2/3 then will stall as if a relief is open but the pump stays up to pressure - then if I hit stick out the boom down will continue until maxed out.

Another symptom may be that when I entered into the CALIBRATE PS PRV-LOW mode the machine will be strong again, but will stall the engine when put under load.

Any advice?

 

[TVA]

Worked on the machine today. Pressures show to be good. I can go into many details, but I this point I would like to know how to calibrate the Power Shift functions if possible. The manual I bought just tells how to measure and adjust all the pressure relief valves and flow control.

The machine seems to move slow in most or functions when under a load even though the pump is producing a little higher than normal pressure. I noticed today that the boom down function will move about 2/3 then will stall as if a relief is open but the pump stays up to pressure - then if I hit stick out the boom down will continue until maxed out.

Another symptom may be that when I entered into the CALIBRATE PS PRV-LOW mode the machine will be strong again, but will stall the engine when put under load.

Any advice?

 

[TVA]

When you hit stick out does pressure in boom down increases?
See if your manual has a pressure value for opening of holding valve.

 

[03hdrk]

Book says to measure pressure at Right pump test port, just FYI, which means I have not measured at cylinder. However, I think it is safe to say that there is something going on in a valve. Did not notice if pressure when stick out … When motion stops on boom down, pressure at right pump is maxed out.
I will look into holding valve.

I have some codes:
Active 1 of 1 - 69:1162.03
Logged events -
1 of 1 69:179
Logged Error:
6 total
69:588-09
167-08
110-10
1161-03
1162-03
96-03

Thanks

 

[Nige]

Your active Code is related to the 2-speed travel. Troubleshooting procedure attached. I don't think it would prevent you doing the calibration (or indeed the calibration from running correctly) but I may be wrong. It may be that ANY Active Code inhibits a successful calibration.

 

[Mobiltech]

I think you need to stick with the prv calibration first.
I tried to upload the info but I cant do it on this laptop. Can someone with sis post it?
If you have a book it will be under the electronic control testing and adjusting, its not in hyd system info

 

[Nige]

Is this what you're after..?
There is also a PRV Sweep Test but to perform it requires a Test Harness which I'm fairly sure the OP will not have, although looking at the diagram below it appears to be a fairly simple thing. Indicates "used to check operation of PRV solenoid be measuring a current signal (sweep test)"

 

[03hdrk]

Thanks to everyone. I got it resolved today. Here is a summary.
I found some info online that indicated that the code is also referencing Pump 2 pressure sensor - shorted high. The 2 speed travel was definitely being affected - it would not work after a short warm up according to the operator. I ended up testing the circuit at the pressure sensors first - There is a battery positive, a ground and a signal. Battery and ground good. Signal measured .7v with key on and 1.3 with engine running - on both sensors. Found the instructions to go to the status screen - then #3 is the reading of the pump 2 sensor. Started working the machine - the reading was about 4000 at idle and would increase depending what cylinder I was moving, but the machine did not seem right still. THEN THE 4000 WHEN TO 0 - tested the voltage on the signal wire again it was fluctuating around 9.4v. Pump 1 still the same. Unplug sensor and the voltage would goto 4.4 and would not throw a code just FYI - switched sensor and the code followed to pump 1. THE SENSOR AND A HARNESS REQUIRED FOR THE NEW PART NUMBER WAS $800 WITH TAX. Machine works as it should.
Some of the info on the internet that I found was incorrect and even the wire colors on the "correct"electrical diagram were incorrect but the "A" "B" C" terminals on the connector and diagram were correct.

Interesting note: this problem was five years old and they continued to use the machine. They were having to bring the loaded bucket close to the machine to lift it - so you can imagine how less capable it was. AND THEY LAYED THE MACHINE OVER ON A HILL - they tracks would not move fast enough or sometimes at all as they were working on a hill causing the operator to lay it over as he moved on a hill. Said the operator knew to stop the engine so they manage to get the oil out of the cylinders and no harm was done.

 

[Nige]

One question. You mentioned that you got a lot of information from the internet. Is this also where you got the "correct" electrical schematic..?

 

[03hdrk]

No, I did not find the 100% correct schematic. I ordered the manual that correctly matches the SN and the wire colors and even the wire numbers were different. I basically made an assumption bases on my knowledge regarding each wire's function - black assumed as ground, left me with a purple and a yellow - in the manual A,B C on the deutch connector were labeled as B+, (-), and Signal - black was in the same location to I went with the ABC location in the connector - even though the only wire number I could read was on the purple and did not match any of the wire numbers on the schematic. I also had a tech from Holt Cat on the phone and asked him if this was the write schematic and he confirmed that this happened all the time. Correct schematic just does not have the correct colors and numbers.

Hope this makes sense.

Without the internet, my job would be way more difficult. People like you "Nige" make this site worth visiting. Whether you have helped me directly, or just by me reading other post you have replied on - you have helped me many time.

Thanks

 

[Nige]

Just for sh1ts & giggles post up your Serial Number. I’ll find the Schematic from the system and you can see if it’s any different to the one you have.

 

[03hdrk]

SN was pac00750 - already sold the manual to the owner of the machine so I don't have it anymore. I could go by memory, but these days I would not be sure of my memory regarding the wire colors - I think they were black purple and yellow on the machine - wire number on the purple was the only one I see a partial that did not match any of the print. If the operator does not like the way it runs they may ask me to do more calibrations at which time I think I will need the Volume one of the service manual. But it will be a while before they get it on the job

Thanks

 

[Nige]

For that machine the correct schematic is RENR7088-01. The schematics on the internet are often not genuine or if they are, they are not the latest version. If you'd like a copy drop me a PM with your email address and i'll mail it to you as a pdf file.