Just bought a 1988 John Deere 450G yesterday 4630 hrs in really nice condition. All new undercarriage original owner. When I was testing it out i noticed that the brake peddle took a little more pressure to apply and went down to fare I thought. It's the long brake peddle in the middle with stick steering am I correct that that is a Direct Drive Not Torque Converter drive. I've gone through the forums and can't find anything much about this. I did read in one that the peddle should pump up when you take the park brake off not sure if that correct. And is anyone familiar with maybe they just need adjusting and if so how? Haven't got a shop manual yet. Any help would be great thanks.
Need a serial number. Make sure all the linkage is free from binding and corrosion. If you just apply the center brake pedal with a machine with steering levers the brake bands apply but the steering clutches remain engaged. So stopping the machine with just the pedal won't happen. If you pull both levers to apply both brakes then the steering clutches will disengage allowing stoppage. Make sure it is Operation and Test Manual TM1403. You definitely need this to adjust the brakes properly. Operators Manual OMT163974 would be of use as well.
So by pressing the left disengage peddle and hitting the big brake peddle you still need to pull back on the steering levers also to stop? I found a OEM Tm1404 manual hope that one covers this machine they sure aren't cheap but a lot better then reprints. I've owned two D4D Cats and a Case 450 this is my first John Deere. Thanks for the help. The serial number is *T0450GF744789*
No, pressing the left pedal and the center pedal will stop the machine. Just pressing the center pedal by itself though won't stop the machine.
Ok Thanks that's what I thought. The big brake peddles seems to go down a long ways is it just hooked to some band brakes that can be adjusted up? And will that OEM TM1404 manual work for this Dozer hope I didn't waste my money.
Ok new at this John Deere manual thing but figured out that TM1404 are for the same machine as TM1403 it looks like. Is the TM1403 included in the TM1404 manual don't want to waste money on duplicate manuals. Thanks
No the TM1404 does not include the TM1403 or vice-versa. TM1403 is the Operation and Test manual which will have all the diagnostic procedures, adjustment procedures and schematics. TM1404 is the Repair manual which is how to disassemble and assemble everything except the engine which is yet another manual which I think for your machine with the 4276 engine would be CTM4.
Got the JD 450G home yesterday. Bought over $500 worth of OEM Manuals for it but they won't be here for a week. I have a question about the decelerator peddle when I start the Dozer the rpm's go up to about 1200 with out holding the peddle down. Shouldn't it idle down to 500 or 600 with the hand throttle at the slowest position. Wonder if someone adjusted the linkage to make it do that.
Got the decelerator peddle fixed it was the end of the cable came apart and was bending when pushed all the way to slow position. All my manuals won't be here for a week free shipping isn't fast. Have a couple problems maybe someone can help with 1st the bulb check lights do nothing when key is turned to that position. 2nd the long brake peddle in the middle does not pump up when the engine is started like it should. Any help would be greatly appreciated.
That spot between on and start? Check the R01 black wire from the monitor to the key switch. When in the bulb check position the key switch provides a ground to the bulbs and the logic module. It won't come up until the park lock lever is raised. Even then if there is enough wear in the park lock linkage that it does not "kick" the FNR lever (shifter) into the neutral slot then the brake pedal won't raise. Same thing if there is enough wear in the shifter linkage that the shift spool does not shift into it's first detent. Are you saying it does not come up at all even when the shifter is in the neutral slot?
I'll check the black ground wire first Thanks . And yes the pedal doesn't come up at all in neutral F or R. The pedal goes to the floor sitting or moving. Maybe not the floor but it has about 5 or 6 inches of travel with very little brake.
Check all the linkages real good first. Also on top of the transmission case towards towards the front and the outside on both sides where the bellcranks for the brakes are there should be a pin sticking up with a spring on it. Are both of them in the up position or stuck in the down position?
Is this under the floor boards or the seat and battery box. Not sure what I need to remove. I just checked again and my manuals should be here Wednesday that will sure help.
I figured it out took the back panel off cleaned out a 5 gallon bucket of dirt. No one has been in there for awhile. Took the bolt out that hold the seat and slid it back kind of handy.
Well after vacuuming over 5 gallons of dirt out I found what you were showing me in the picture. But they look nothing alike here's a picture of mine.
Is it possible that the brake bands can be worn out with only 4600 hrs. And is it a major job to replace them on a 450G lever steering?
You might have to remove the sheet metal from above the track. The pins I am talking about are closer to the track side of the transmission top. How does it steer? How far do you have to pull the levers to steer (in inches). The brakes on those machines are fairly durable. I would wait for the manuals and make sure all the adjustments are spot on.
Ok thanks I'll pull those bottom covers and look . I will measure but you have to pull a long ways on the levers.
Pulled the bottom covers cleaned out all the dirt and finally found the spring loaded pins you were talking about. They are both in the up position one was in oily dirt and the other was not. Soaking it in penetrating oil . Are they important other then towing? Next can't find any slop in the linkage at all it is very tight . So I finally pulled the big plugs were the auto adjusters are bingo the right side has no adjuster and is backed off . So I guess the next step is pull the back cover off and hope I can get to and find the lost parts. Any guidance would be great . Totally explains all the issues I think.
That case holds somewhere around 26 gallons of oil so have plenty of buckets to drain it into. Removing the back cover is a breeze. Self explanatory. However the brake/clutch removal, while not difficult, has a lot more to it than it appears so I would wait until you have the Repair manual to explain the necessary steps. Same with adjustment of the brakes, wait for the Operation and Test manual. There are some very important safety steps to take before adjusting the brakes.
I have a 25 gal drain pan on wheels that worked great . I got my manuals yesterday also. So I took the back off and there are nothing missing on the adjusters. It fooled me because on the right side it is on the back side which is the same side as the left. The case is spotless in side there is about 3/16 of lining on the bands is this about right for 4600 hrs? And there is about 1 inch between the star wheel and the nut on the end of the threaded shaft which I took a picture of but you really can't see it very well. Just need to know if this is all within tolerance the manuals really don't say much about this. Going to put a new gasket on the cover fill it back up with fresh oil and adjust everything like the manual says and see what happens. But would really like to know if the brake lining and that star wheel is ok. Don't know why everything is underlined never had that happen before
Ok one more thought I think pressures might be a problem not sure just a thought. If the Accumulator is low or out would that affect brake function because I keep wondering why the brake pedal doesn't pump up like it should after you start it and take it out of park mode?
While you have it drained check and clean the suction screen mounted on the front side of the case under the floor board. Yes, regardless of the brake adjustment the center pedal should rise all the way. All the accumulator does in this application is absorb pressure spikes, nothing else. I would suggest checking system and steering clutch pressures at this point.
John Deere messed up didn't ship my gasket so waiting till tomorrow morning. Picking up a new O ring for the suction screen housing and clean that. Hope to get it back together and make some progress tomorrow. With all the sensors on this dozer would they have anything to do with the brake pressure if one was not working. Can't imagine but this is the newest dozer I've owned.
Nope
Got the steering brake issue fixed. Pulled the back cover off the transmission everything was very clean. Took the suction screen out very clean nothing on it at all but found a a piece of brass something in the bottom of the can. picture included if someone can identify it for me. Changed transmission filter and then started adjusting the steering according to the book. No play in linkage but levers were pulling to fare back around 9 inches so started manual adjustment until got the pull back down to 5 inches. They were way out of adjustment and were not self adjusting according to the book the stop bolt that goes down threw the top of the case needed to be backed off a quarter turn at a time till they self adjust. I think the part I found may have come from another repair since there were signs it had been in to before. Anyway foot brake works good steering is back to where it should be. Thanks for the help
That brass piece is a thrust washer from one of the clutch packs. I think you will need to figure out where that came from.
help! how to disable the lock engine function? komatsu pc200-8N1 it shows error code D19JKZ and we've already checked all harness and fuses. they're all okay. the engine won't start but cranking, just won't continue
Welcome to HEF Carl ! Please start your own thread in the excavator section. The Komatsu gurus won't see this here.
Thank you. Already started a thread but no one replied yet