Case 450B charge pump?

[Jason86]

HELP!!! I've got a Case 450B dozer that was my grandfather's. He had it serviced a few years ago all fluids and filters were changed and he has always taken very good care of it and used it for his landscaping around his house. He has owned it since it was pretty much brand new and it now has just a little under 3000 hrs on it. I used it for my very first time for about 40 hours last summer on and off without any issues whatsoever other than a little bit of an off and on whining sound that was coming from either the alternator or the charge pump below the alternator, I couldn't pin point which one was making the noise but it was very minimal and only happened a few times on and off. Everything was working fine and then I parked it for the winter. When I started it up last weekend I let it warm up for about 10 min. and hoped on but it wouldn't move forward or backwards none of the drive controls worked at all and the tracks did absolutely nothing, the engine is running great, and the blade works fine and will lift the front end right of the ground. When I looked at the drive shaft it was spinning very slowly and didn't have any torque whatsoever and could be easily stopped with minimal effort but would start to spin again if pressure was released. The colored transmission pressure gauge is not reading anything and the needle is just sitting there dead. I believe when I was using it last summer all of the gauges worked other than the transmission temp gauge.

So my big question is does this sound like the charge pump crapped out or is it the torque converter? It's strange as it worked fine when I parked it and now it wont move at all. My gut feeling tells me it's probably the pump but I know nothing about heavy equipment and wanted to check with someone experienced. I see aftermarket charge pumps listed for around $400 online and was quoted $1200 from a local dealer, was thinking of trying out a pump but dont want to change it out if it's not the problem. Are all the pumps that are being sold all the same manufacture but just being marked up by the dealers or are the online ones a cheap knockoff? There seems to be a big jump in price range on these things. I really appreciate any thoughts or solutions. Thank you Jason

 

[AJ.]

Don't despair,the most likely thing that's wrong is it lost it's prime,(the oil has ran back to the transmission)there are two lines attached to the pump trace the one going to the suction strainer and remove it from the strainer,point it upwards and stick a funnel in it pour in a couple of pints of oil,fill the funnel and wait till it goes through,connect the line back to the strainer and try,if you have success have a look around the transmissions for any breathers it may have that could be blocked causing a vacuum.
Good luck
AJ

 

[marloweg]

the oil lines run on the in side of the frame rail and they get packed with dirt and rust holes in them and you will lose prime had to change mine on two machines with hyd. hose

 

[Phil H]

Hi Jason, I had the exact situation for my 450 track hoe. I replaced the engine with a brand new rebuilt, and EVERY thing I could think of, and I do mean EVERY thing. Hydraulic pump, torque converter charge pump, and new lines, new fuel pump, new torque converter, new flex plate, YOU NAME IT!!! I ran it and everything was perfect. I worked the machine for about 40 hours, and I noticed the torque converter pressure was low, about 30 lbs. This is what I did. Check for vacuum leaks, make sure the hoses are clamped tight going to the charge pump. remove the screen filter on the inlet to the pump make sure it is clean. I found, after replacing everything the hydraulic oil in the trans. was low, so low it would not come up on the dip stick. The oil is so clear you can hardly see it. I added about 2 gallons of oil and WOW. All is good. The only thing I can think of, is the torque converter needed to be filled along with all the lines that were replaced, and that was enough to lower the amount of oil in the sump of the transmission. When I first ran everything the oil was thick, but using it the oil thinned out and the pressure dropped. I would check that oil level, park the machine so the front of the engine is down hill, so oil will flow into the pump, I doubt very seriously the torque converter is bad. Maybe the noise you heard was from the pump not having enough oil in it. I would try parking on a slope and add oil, I will bet your problem will go away. Phil H

 

[Jason86]

Thank you for the help guys. I ended up filling the large hose on the charge pump up with oil and started it up. I had to rev the engine up pretty high and it took about 5 seconds of holding the throttle down but it finally primed and have pressure back on the gauge. The dozer was parked over the winter with a very slight back tilt so I'm assuming the oil drained back into the transmission, this fall when I park it for the winter it will be parked on the pallets with a slight forward tilt in hopes it doesnt happen again. I looked over the steel lines and everything looks to be in good shape and I dont see anything leaking to cause a loss of prime and the transmission dipstick tube vent appears to be clean so I will just go from here at least I know what to do if it happens again. Thanks again for the help.