Construction and Road Equipment

Construction and road equipment repair questions? Ask a mechanic ASAP

Connect one-on-one with {0} who will answer your question

This answer was rated:

I have no hydraulics at all on a 2006 Cat 277B (MDH4477).

I have no hydraulics...

I have no hydraulics at all on a 2006 Cat 277B (MDH4477). The machine has been sitting for several months as I had to have a final drive rebuilt. I put the motor on yesterday and was bleeding lines. I moved the tractor forward and backward a couple of times and everything was working fine. then it just stopped. Hydraulic pump is still moving oil because I can hear it circulating in the tank. Park Brake releases and the solenoid in the left joystick engages, however, there's no pressure change at the joystick, like there normally is, and nothing hydraulic is working. No lights are flashing, everything is normal. I checked the relay's and they are both clicking, I didn't have a meter with me in the pasture to see what they were reading. The 10a hydraulic fuses in the box are good. I don't know what else to be looking at. Like I said, they just stopped working...period.

Mechanic's Assistant: Sometimes things that you think will be really complicated end up being easy to fix. The Heavy Equipment Mechanic I'm going to connect you with knows all the tricks and shortcuts.

I have no hydraulics at all on a 2006 Cat 277B (MDH4477). The machine has been sitting for several months as I had to have a final drive rebuilt. I put the motor on yesterday and was bleeding lines. I moved the tractor forward and backward a couple of times and everything was working fine. then it just stopped. Hydraulic pump is still moving oil because I can hear it circulating in the tank. Park Brake releases and the solenoid in the left joystick engages, however, there's no pressure change at the joystick, like there normally is, and nothing hydraulic is working. No lights are flashing, everything is normal. I checked the relay's and they are both clicking, I didn't have a meter with me in the pasture to see what they were reading. The 10a hydraulic fuses in the box are good. I don't know what else to be looking at. Like I said, they just stopped working...period.

Show More
Show Less
Ask Your Own Construction and Road Equipment Question
Answered in 15 minutes by:
7/7/2020
Mechanic: Dan, Technician replied 2 years ago
Dan
Dan, Technician
Category: Construction and Road Equipment
Satisfied Customers: 15,122
Experience: 17+ yrs. shop and field experience with all major brands of heavy equipment and trucks - 1995 WyoTech graduate.
Verified

Hi, It is Dan. I will be glad to help. We can follow up as needed on here, Give me some time to review your information and follow up with my responses. Professionals are not employees of the site but users of the site and help on here as time allows in between jobs, family,etc. Response time can vary depending on my work load each day but I will always respond back on my next available login. Feel free to respond back at anytime if for any reason we seem to get separated,for status, etc.

Ask Your Own Construction and Road Equipment Question
Mechanic: Dan, Technician replied 2 years ago

Sorry to hear you're having troubles with this machine. If all of your safety interlock switches and wiring as well as your other components within that circuit check out okay, you have lost all functions, it truly leans towards a possible pump drive coupling failure. The coupling could have failed in such a way that the pump may turn a little here and there but not enough to build pressure for any functions if it is slipping on the shaft or the splines have stripped. Remove your charge pump at the end of the main pumps, disable the fuel from starting at your fuel shut off, then crank the engine to see if the pumps are turning at engine RPM when cranking the engine over. Also check inside your hydraulic filter for any signs of fine metal or debris that looks like glitter in the oil and filter which would flag a hydrostatic pump or component failure has occurred. If all this is clean, you're going to want to get some test gauges and a flowmeter on this machine. I have a feeling that you may very well find a problem with the pump drive coupling. It's a pleasure to help anyway I can.

Ask Your Own Construction and Road Equipment Question
Customer reply replied 2 years ago
Okay, thank you. I will begin working on this today
Mechanic: Dan, Technician replied 2 years ago

You are very welcome.

Ask Your Own Construction and Road Equipment Question
Customer reply replied 2 years ago
Hi Dan~
I just checked the shaft and splines on the charge pump. They look good as new. I was unable to actually crank the engine and look at the pump because I’m out here alone and, with the cab up, I’m unable to be in a position to see what’s going on. Here are a couple of things that I found though. Let me back up to the original issue, though, as this might tell you what happened. The bottom hose on the final drive was loosened a bit so that whatever air might have been in it could bleed out. Under pressure, the o ring gave way and oil went everywhere, of course. I replaced the o-ring and tightened everything back down thinking that the air was out, being as fluid came through that hose and it was full. What I think happened is that it sucked air into the line. Reason I say that is because when I released pressure on other fittings around the pump, the oil was frothy. Air released and it, eventually started coming out clear. Also...I can hear bubbling in the fluid tank. I don’t know how I can get the air out. Do you think that might be why it’s not building up enough pressure?
Thanks,
Lesthe filter is clean...no metal or anything like that...just a bunch of tiny bubbles. It was not full to the top so I topped it off and replaced it
Mechanic: Dan, Technician replied 2 years ago

Hi Les, the system should bleed itself out with the oil level full and even if you experienced a little bit of cavitation initially from not having the bulk of the air out of the system, it still should've come out of it. Usually with the engine off or fuel shut off disabled, you can either crack loose one of the lines and in some cases there is a plug or case drain that you can crack loose to bleed some arrow while cranking the engine over before allowing the engine to start. It is not the splines on the gear pump that is concerning. It is the pump drive coupling between the engine and the main pumps that usually fail and in some cases the couplings between the pumps. If no sign of glitter or pump and component failure is found in the oil, I think it's very important to see if you can get a helper out there to either confirm or condemn the theory of a pump drive coupling between the engine and hydraulic pumps. If there is any way you can get a remote start switch connected to the starter assembly which will give you remote access, I would attempt to do so shy of having a helper out there. And even if the pump turns a little bit you want to be sure that it's turning consistently at engine RPM when cranking over.

Ask Your Own Construction and Road Equipment Question
Customer reply replied 2 years ago
Okay, I will figure something out so we'll know for sureSorry this is taking so long...lol. Machine in the middle of pasture and I'm the Lone Ranger out here on this ranch...
Mechanic: Dan, Technician replied 2 years ago

If you can grab a remote start switch from your local auto parts store or if you have a momentary switch, you can make your own start switch with some wiring and some alligator clips to send 12 V to the starter solenoid signal wire or S terminal.

Dan
Dan, Technician
Category: Construction and Road Equipment
Satisfied Customers: 15,122
Experience: 17+ yrs. shop and field experience with all major brands of heavy equipment and trucks - 1995 WyoTech graduate.
Verified
Dan and 87 other Construction and Road Equipment Specialists are ready to help you
Ask your own question now
Was this answer helpful?

How JustAnswer works

step-image
Describe your issueThe assistant will guide you
step-image
Chat 1:1 with a mechanicLicensed Experts are available 24/7
step-image
100% satisfaction guaranteeGet all the answers you need
Ask Dan Your Own Question
Dan
Dan
Dan, Technician
Category: Construction and Road Equipment
Satisfied Customers: 15,122
15,122 Satisfied Customers
Experience: 17+ yrs. shop and field experience with all major brands of heavy equipment and trucks - 1995 WyoTech graduate.

Dan is online now

Related Construction and Road Equipment Questions
I have a cat 287b. It doesn't want to turn from stationary,
I have a cat 287b. It doesn't want to turn from stationary, but will turn fine while moving forward and backward … read more
Dan
Dan
Technician
Auto Mechanics 1&2/diesel mech
15,122 satisfied customers
I'm back on that 287c MAS01944 The code e571-2 isn't due to
Hello! So I'm back on that 287c MAS01944The code e571-2 isn't due to the hoses as I previously thought since I rearranged them to correlate with the cats factory hydraulic diagram.I realized that the … read more
catmastertech
catmastertech
Field service technician
Vocational, Technical or Trade Scho
1,325 satisfied customers
For catmastertech the left pilot solenoid replacement seems
for catmastertechthe left pilot solenoid replacement seems t have taken care of the electrical issues _ Yah!There is a remaining issue of the draw down on power after the right stick is used 9/10 time… read more
catmastertech
catmastertech
Field service technician
Vocational, Technical or Trade Scho
1,325 satisfied customers
I recently purchased a 2006 Cat 252B and unfortunately the
I recently purchased a 2006 Cat 252B and unfortunately the middle section of the Operators manual is missing. I'm not sure the process to engage the auxiliary hydraulics. I've confirmed all the fuses … read more
catmastertech
catmastertech
Field service technician
Vocational, Technical or Trade Scho
1,325 satisfied customers
2009 CAT 247b2 serial # CAT0257bvslk07704 Have right
2009 CAT 247b2 serial # CAT0257bvslk07704Have right joystick with thumb roller. Was running rock grapple and it quit responding. Would open and close sporadically. Would have to move roller back and f… read more
catmastertech
catmastertech
Field service technician
Vocational, Technical or Trade Scho
1,325 satisfied customers
Re: Cat 277B (MDH4477) I parked the machine and it was
Re: Cat 277B (MDH4477)I parked the machine and it was operating fine. I replaced an outboard bearing and, once completed, I attempted to move the machine. The left hydrostatic drive will not move. The… read more
catmastertech
catmastertech
Field service technician
Vocational, Technical or Trade Scho
1,325 satisfied customers
I'm helping a friend try to diagnose the steering issues
I'm helping a friend try to diagnose the steering issues with his TB42 snorkelift. The machine will move forward / backward but the steering seems to be locked out. As in the joy stick will not move f… read more
Curtis B.
Curtis B.
Technician
Associate Degree
2,324 satisfied customers
My Cat 277B auxiliary hydraulics stopped working completely.
My Cat 277B auxiliary hydraulics stopped working completely. The 1st sign that they were going out was when the grapple would fully open it would shut off the auxiliary power. I would press the park o… read more
Mikael
Mikael
Bachelor's Degree
150 satisfied customers
My Cat 289c high flows lock the arm movement. I can go back
My Cat 289c high flows lock the arm movement. I can go back and forward but can't move the arms up and down or tilt. I notice the machine works normally until I move the right joystick to the right.… read more
catmastertech
catmastertech
Field service technician
Vocational, Technical or Trade Scho
1,325 satisfied customers
I have a Cat 420eit sn:DAN00662 when i put it in any gear
Hi there. i have a Cat 420eit sn:DAN00662 when i put it in any gear and push the direction lever to forward or reverse i get a malfuntion light and audible alarm but the machine will drive. any idea w… read more
catmastertech
catmastertech
Field service technician
Vocational, Technical or Trade Scho
1,325 satisfied customers
I have a 2006 cat 277b with the aux thumb wheel. Is there
I have a 2006 cat 277b with the aux thumb wheel. Is there any way of locking the hydraulics so I dont have to hold the thumb wheel while power raking … read more
catmastertech
catmastertech
Field service technician
Vocational, Technical or Trade Scho
1,325 satisfied customers
I have a cat 277b and the auxiliary hydraulics are
i have a cat 277b and the auxiliary hydraulics are constantly running causing the plow attachment to drift to the left i can hear the hydraulics hissing when the machine is running but if i hole the t… read more
catmastertech
catmastertech
Field service technician
Vocational, Technical or Trade Scho
1,325 satisfied customers
I have a 226B cat skid steer. The hydraulic controls for the
I have a 226B cat skid steer. The hydraulic controls for the bucket open and close have gone haywire. How to diagnose the problem is my ?… read more
catmastertech
catmastertech
Field service technician
Vocational, Technical or Trade Scho
1,325 satisfied customers
I have a similar problem right now with a cb534d not moving
Hi I have a similar problem right now with a cb534d not moving front or back. Have done the handle calibration with success. But still have the 5-2 flash code. Neutral fault. I would like to know how … read more
Dan
Dan
Technician
Auto Mechanics 1&2/diesel mech
15,122 satisfied customers
Cat 248 high flow skid steer Lift arm/bucket hydraulics
cat 248 high flow skid steer Lift arm/bucket hydraulics won't operate. When it first happened the parking brake light came on, I pushed the button to release the parking brake. The indicator light wen… read more
Dan
Dan
Technician
Auto Mechanics 1&2/diesel mech
15,122 satisfied customers
I have a 2004 caterpillar 287b track machine. Joystick
I have a 2004 caterpillar 287b track machine. Joystick control. When going forward, I let go of joystick to center position to stop and the machine comes to a stop but also turns to the right. Then it… read more
Dan
Dan
Technician
Auto Mechanics 1&2/diesel mech
15,122 satisfied customers
I have a cat 247 b2 that blew a hydraulic hose yesterday. i
i have a cat 247 b2 that blew a hydraulic hose yesterday. i pulled the hose and changed it out. i then refilled the hydraulic fluid and started the machine. it wont move forward or backward as well as… read more
Wayne
Wayne
Journeyman
Vocational, Technical or Trade Scho
1,298 satisfied customers
Have a cat D5C #6CS01127. Rt side track will not move. when
have a cat D5C #6CS01127. Rt side track will not move. when you hold joystick to left to make rt track move you can hear the hydraulics whine like its building pressure. worked off and on before faili… read more
catmastertech
catmastertech
Field service technician
Vocational, Technical or Trade Scho
1,325 satisfied customers
Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

JustAnswer in the News:

Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.

What Customers are Saying:

Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help.

Mary C.Freshfield, Liverpool, UK

This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!!

AlexLos Angeles, CA

Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult.

GPHesperia, CA

I couldn't be more satisfied! This is the site I will always come to when I need a second opinion.

JustinKernersville, NC

Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around.

EstherWoodstock, NY

Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know.

RobinElkton, Maryland

He answered my question promptly and gave me accurate, detailed information. If all of your experts are half as good, you have a great thing going here.

DianeDallas, TX

< Previous | Next >

Meet the Experts:

Curtis B.

Curtis B.

Technician

2,324 satisfied customers

Technican turned service manager with multiple lines of equipment and rental units.

Wayne

Wayne

Journeyman

1,298 satisfied customers

worked on many road graders, Bull dozers , skid steers, Rollers

Cat Man

Cat Man

Cat Engine Expert

578 satisfied customers

I am ASE Master Certified.

dieseldan55

dieseldan55

Mechanic

299 satisfied customers

Road Mechanic for Volvo Construction Equipment.

Chris (aka- Moose)

Chris (aka- Moose)

Technician

85 satisfied customers

24 years of experience diagnosing & repairing

Steve

Steve

Mechanic

42 satisfied customers

Heavy Equipment Mechanic for 25 years

JBFixxer

JBFixxer

Mechanic

22 satisfied customers

16+ years experience, hydraulics,hydrostatics, engines, fuel injection systems. And everything in between.

< Previous | Next >

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Show MoreShow Less

Ask Your Question

x