hydraulic fluid flush advice

[dozingdozer]

Guys,

i posted a problem with loss of reverse drive and didnt get much of a response so i am assuming my problem should be obvious to me, or more easier to diagnose after some proper maintenace and fluid changes. got my gaskets and filters and will get on it soon. do you guys have any advice for flushing the hydraulic systems , tranny and reverser ,to flush out the gunk in there,prior to the first oil change out? trans fluid is chocolate milk and reverser is not as bad, but assume filter is totally gunked? Any additives to run or cycle through to help flush the system?
Thanks,
previous post:

My 75 350c, with a slight leak on the reverser coolent return line, works fine and pushes well but than after 20 or 30 minutes reverse direction gets weaker until it doesn't engage. As it starts to go i can get it to operate in reverse by pushing in and letting out clutch pedal. No loss in forward. I haven't changes the fluid filters yet, waiting for 5ft of snow to melt , but the fluid is relativly new in reverser and up to level. when problem happens i let it sit and cool down for an hour and i can then get 5-10 minutes of reverse power out of it and then it fails again. any thoughts or suggestions?

[gerald]

Dozingdozer,That is a wet clutch hyd activated. I would think there is a directional valve or relive valve in the system for reverse. It sounds like your clutches are ok working in forward gear. What is your service manual say. Let us know .

[KenP]

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[gerald]

Dozingdozer. Since the transmission is a different system should have no effect on reverser and hyd system. Your reverser oil is clean. I had trouble with my hyds and changed the oil it was perfect. The reverser an hyd system are different system. It takes nothing to clean the hyd system out 1 oil change should do it , just wipe out the inside of the tank good.

[dozingdozer]

thanks for the feedback and advice. i think I can plow out a work surface in the snow piles and get to work on the basics.

[digitup2]

When it comes to getting water out of transmision oil you have to replace the oil and filter completly.With a hydraulic system this is easyer than replacing the oil what I do is get one of those moisture absorber units on a cord that removes water from a fuel tank .It is just a round screen with a bag of jell absorbant in it and a cord on it now hang this in the reserve tank so it can't be sucked out with the pickup pipe leave it in and run several times this will remove all water then when oil cleans up remove and discard the moisture absorber .Try to figure out where the water is getting in so this problem dosn't return I had to do some looking around for a moisture absorber but when it worked it worked well It isn't even ment for hydraulic oil just gas or diesel but works great for me and well worth the 20 bucks price tag .I keep several around just for this joband they will only remove so much water so use some better judgement in this area but after several runnings the oil will be cleared up .Digitup.

[gerald]

Dig it up, Good idea removeing water from oil. With Stright 350 it's even tougher getting water out of transmission there is no filter. just the drain plug and half inch filler plug.With my Hyd system it has 2 filters and was easy like I posted but when I hooked up the hoe it contaminted the system again . I need to draw in all the hyd cylinders, dump the oil pull both filters and wipe it out again . Like kemp said do all the PM first then go after the magor proublems. gerald

[dozingdozer]

first order of buisness is complete fluid change outs and filters. this machine was sitting unused and out for years and so far repsoneded to basic tlc and cleaning and grease well and is relativley low hours at 2900 for a 76. might not get to the change out until march when this deep stuff starts to melt hopefully. thanks , dd

[MikeH]

Firstly you gotta see your whats in your service manual. Change the fluid first and see what happens and after that change the filters.