Cat 140H park brake flashing in gear

2007 cat 140H cca02481 6000 hours
Fault codes
0300271.05
0360549.02
3 days after purchasing this beautiful grader . I started having transmission issues. Lost 3-4-8 and Fault codes led to low voltage on solenoid 5. Changed solenoid, didn't help. Changed cartridge, didn't help. Brought it to a shop they said it was ECU. Changed ECU and fixed gear lose. But now after $11000 went back to work and now have parking brake light flashing in gear. I wish I could just take it back and might have to but was not impressed with some of the work they did. Seems if I put it in park and rev it up take it out of park the light stops flashing. Then will randomly come back mid push. Once again thank you to all helping folks like me chase their stupid f@#$&+g dreams.

The machine main harness goes through the articulation point of the machine. If any of the clamps that secure it to the frame are missing or broken. Then you likely have broken wires. It's also possible that the wires are broken even if your clamps are intact. That is worse case scenario. I would plumb a gauge into the park brake and see if you are dropping pressure when the light comes on. Best case scenario is a failing solenoid.

What you also need to consider is that there was an upgrade on the transmission control valve to assist in preventing failures of #7 clutch. That upgrade was before your machine (around machine CCA02187, transmission EBD04459-Up) ) and it used different clutch pressure settings to the unmodified machines. Set up a transmission using the wrong pressure test specifications and you could be in for a world of hurt.

Attached the troubleshooting procedures for your two Diagnostic Codes. At first glance neither of them are related to your flashing park brake light. Either way you need to fix them.
I'll send you an electrical schematic. You'll probably need one.

Please post a photo of the light that is flashing, just to eliminate all doubt.
Better still, which one of the illustration below is it.? I'm guessing #8.?

Have inspected articulation area all clamps are present and harness cover is all intact. Looks healthy, but inspect closer today. Thank you

Do you have any way of tapping a pressure gauge into the supply line to the park brake to check what the actual pressure is in the system when the light is flashing.? Maybe the light is flashing for low air pressure.? IIRC the light going off is linked to the signal from a pressure switch.

Do you have any way of tapping a pressure gauge into the supply line.

Will figure a way of doing that today. The machine itself holds air really well. Also doesn't drag at all when I coast. I realize this could still be the issue so will do that. Will drain park brake too.

I think it would be a good idea to make sure that the light isn’t coming on because of a lack of air pressure before starting to chase possible wiring faults.

Cassidy said:

2007 cat 140H cca02481 6000 hours
Runs great first couple hours then starts to drop power and run rough, like there's air in system. (Fuel level not a factor)
Have changed check valve, lift pump, fuel cap, and filters. Checked and blew hoses. I have noticed the primary filter gets really hot. The sump gets so hot you can hardly touch it. Maybe that's normal?

Click to expand...

From your other thread. Better to keep it all in one place I think.
First thing I would suggest is to get hold of an infra-red non-contact thermometer, then you will be able to quote actual temperatures rather than your impressions of how hot things are. This will help.

Any black exhaust smoke at all, excessive or otherwise.?
Does the amount of smoke change when the engine gets hotter.?
Have you been into the air filters at all.? What do they look like and/or what does the filter restriction indicator say.?
Do you have any idea when the engine last had a valve adjustment check/set.?
Next thing after checking the air pressure in the parking brake circuit (see above) might be to check the turbo boost.

Cassidy said:

Will figure a way of doing that today. The machine itself holds air really well. Also doesn't drag at all when I coast. I realize this could still be the issue so will do that. Will drain park brake too.

Click to expand...

Confirmed the park brake light in the Monitor Panel is operated on/off by a pressure switch.
Effectively the monitor looks for continuity to machine frame ground via the park brake switch on wire 419 Yellow.
When the pressure in the park brake circuit rises above +/-90psi the switch closes.
The other side of the park brake pressure switch is connected to ground via wire 201 Black.
As soon as the Monitor Panel "sees" ground on 419 YL that is the signal for it to turn off the park brake "ON" light.

Ok thank you Nige. I will delete the other thread.
So I found the sensor with the 419 wire on it. Removed it and put a pressure gauge on it. Seemed to be getting similar pressure to cab gauges. Swapped the sensor with a different one on the machine and the problem followed the sensor. Bought new sensor will replace tonight. Thank you so much Nige.

Glad I could help. Please come back and let everyone know if that definitely fixes the problem.

EDIT: Above you said "swapped the sensor with a different one". Do you mean you swapped the Park brake pressure switch for the main air system pressure switch, because the two switches are both the same Part Number.?

As for the fuel issue.
It hardly smokes no matter the condition.
Air filters are good and indicator shows zero resistance.
I do not know when the valves were adjusted last.
So more on this problem.
It's hard to narrow down cause it won't do it till it's really working. Then I get on the highway to take it to my house and it runs like a top as soon as it touches the asphalt. I originally thought it was the new fuel filter I put on cause it was a Baldwin and the o ring wasn't as thick causing the housing and the metal part of the filter to touch. Figured it wasn't sealing right. Put a cat filter on and it fixed the problem 30%. Then I proceeded to throw parts at it... Only thing left is the hand primer which is likely due anyways. What strikes me as odd is how great it runs for the first few hours. I can say with confidence the engine is up to operating temp in the first 30 mins in this stuff.
The reason I'm asking about the hot fuel is that sump design really only cycles the fuel in the sump not through the tanks. It's safe to say somewhere in this graders previous life it got burried up to its teets in a swamp. I've keep cleaning the sump and under the engine and finally getting it hoping that solves it. Even between the hyd pump and the frame was right full thinking the heat is just compounding. Bare in mind I come from more of the operator side, so grain of salt... Thank you everyone.

By the sounds of the mud you have removed so far from underneath the engine, the sooner you get it completely cleaned the better.

These machines have a sealed fuel cap and vent the tanks through a small hose on the right hand side. You should probably check that it's not bunged up in the sh!t under the engine.

This is the location on the RH fuel tank that the vent hose CMark referred to above comes from.

Managed to get her to work a full shift but not without its wobbles.
Parking light gone and no lights all day.
Cleaned out all the dirt I could reach last night and definitely helped cause I made it past lunch and it was warm here today.
Then my hydraulic system started whinning. Pressuring the tank and hot. (Apparently I need to learn all the systems before I get one check out of her .) Which may or may not have finally caused my lower power issue to come back.
Looked for vent line and all I could find was a small line that led to sump.
I will note I have tried popping the cap when it's acting up and have never observed any type of vacuum pressure. Also tried running with lose cap and did not help.
Once again thank you guys

Is there a hydraulic temp gauge (or just a warning light for high hyd temp) on your machine.?

You really need that infra-red thermometer sooner rather than later.

Definitely no gauge and didn't have any lights flashing. Working on thermometer. Unfortunately I've been 3 steps behind ever since this thing came into my life, and my dirt project is ridiculously behind.