materthegreater
Senior Member
Thanks for the offer! I've asked two guys locally so if neither has one I may take you up on it. What type of fitting does it have?
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2019 Deere 75G
- Thread starter materthegreater
- Start date
Columbo
Senior Member
This is the setup I have, I believe the gauge is 1/4 male NPT and I have an adapter down to 1/8 male NPT. I had it setup on my cat excavator when I was chasing a fuel issue. Let me know if you’re interested in using it.
materthegreater
Senior Member
Thanks for the offer. I was able to find a 0-15 psi gauge which should make it easier to read if the pressure drops below 1 psi.
I'm hooking it up now.
materthegreater
Senior Member
Just over 1 psi at idle
It drops to basically 0 when a load is applied.
It drops to basically 0 when a load is applied.
Columbo
Senior Member
You’re welcome! Waiting to hear the results…
Columbo
Senior Member
Well, I guess that’s pretty clear….
materthegreater
Senior Member
Thanks for the idea to check this. Could it be as simple as a bad lift pump? Or is there some sort of regulator in the filter housing that is supposed to maintain proper pressure?
Columbo
Senior Member
I’ll let on of the Deere guys chime in, but if it were me I’d disassemble every hose and fitting from your test point back to the tank and blow each one out with brake cleaner then compressed air. If you blow them into a clean bucket you’ll see if any crap comes out. Also, look for possible air leaks along the way. Then, reassemble, prime the system and retest. If you still have a low reading I’d suspect the lift pump. Someone more familiar with Deeres may have a specific place to check or know of an inline screen filter like Cat likes to hide in there.
materthegreater
Senior Member
I disconnected the hose coming from the fuel tank and blew through it with compressed air to make sure that it wasn't partially plugged (fuel was gushing out before and after blowing it out but I wanted to be sure). I bypassed the suction filter/water separator and connected the inlet of the pump directly to the supply hose from the tank. Then I put the gauge on the output of the pump (not teed, but deadheaded) and it will build almost 4.5 psi. That's as far as I've gotten today.
Columbo
Senior Member
mg2361
Senior Member
With the gauge tee'd so you can run the engine, what is the fuel pressure at key on, engine off?
Fuel pressure should never reach zero when under load.
DTC 157.18 (P0094) Rail Pressure Deviation Error During the Actual Rail Pressure Drop.
Check your messages. (both of you)
Fuel pressure should never reach zero when under load.
DTC 157.18 (P0094) Rail Pressure Deviation Error During the Actual Rail Pressure Drop.
Check your messages. (both of you)
Last edited:
Columbo
Senior Member
@mg2361 thank you for the detailed test instructions! @materthegreater, looks like you’ve got the next steps laid out pretty well.
materthegreater
Senior Member
Columbo
Senior Member
Keep us posted!
materthegreater
Senior Member
A little progress today. I did the flow test for the transfer pump, and it flows about twice the minimum volume - filled a 16 oz pyrex in about 30 seconds (going through both filters).
Next I started trying to access the high pressure pump so I can get the gauge installed in the recommended location instead of at the filter head where I had it previously. I ran out of time before I was able to get it connected and do the pressure tests.
Next I started trying to access the high pressure pump so I can get the gauge installed in the recommended location instead of at the filter head where I had it previously. I ran out of time before I was able to get it connected and do the pressure tests.
materthegreater
Senior Member
Ok, I gained access to the injection pump and put the tee and gauge in the recommended locations, using clear hose. Here are the results:
Key on engine off: 4 psi
Key on engine idle: 1.5 psi
High idle no load: 1 psi
High idle under load: 0
Moving on to check tank outlet, though I'm doubtful that it's the problem because it passed the flow test going through both filters.
Key on engine off: 4 psi
Key on engine idle: 1.5 psi
High idle no load: 1 psi
High idle under load: 0
Moving on to check tank outlet, though I'm doubtful that it's the problem because it passed the flow test going through both filters.
materthegreater
Senior Member
I cleaned the fuel tank outlet and the final filter head. No obstructions at either.
Same results at the gauge. My next thought is replace the transfer pump. Even though it flows well at no pressure, and it builds proper pressure at KOEO, it doesn't seem to be able to maintain pressure and flow simultaneously.
Same results at the gauge. My next thought is replace the transfer pump. Even though it flows well at no pressure, and it builds proper pressure at KOEO, it doesn't seem to be able to maintain pressure and flow simultaneously.
materthegreater
Senior Member
Now, why would they have it listed as a 12v pump? The machine is clearly 24v.
mg2361
Senior Member
Interesting. Don't know. That pump is used on many machines, both 12 and 24 volt. Our parts system does not list specifications for that pump.
materthegreater
Senior Member
I assume there are two different pumps, surely the same one can't run on both 12 and 24 volt?
Is my thinking correct that I should try replacing the pump next?