Case 850D Dozer blade hydraulics

Old Bob · Sep 16, 2017

Got a Case 850D dozer. Has a 6 way blade.
Hydraulics spool for blade has a leak. Took the
spools to a hydraulic shop and they put new o rings
in it.

Put it back on the dozer. Still have a leak. It is on
the tilt control of the of the blade. It is a drip out of
the bottom of the valve that works the tilt. Does not
leak if you are not moving the lever to change the
tilt on the blade. When you move the lever to
change the tilt it drips out of the valve that controls
the tilt.

Don't know if I have used the correct terminology
describing my problem.

Thanks in advance.

AJ. · Sep 17, 2017

It seem to be leaking only when under pressure,you will need to know exactly where it is coming from,if its leaking from the around the spool under the lever or from the cap on the bottom,did the shop say the spool was scored or the bore damaged,the o'ring's that is on the top and bottom of the spool is to catch any leak bypassing the valve which is a slip fit,did the shop take the segments apart and renew the o'rings between them,study the leak and find where it is coming from.
AJ

Old Bob · Sep 17, 2017

Leak is only a drip. Coming directly out of the
bottom of the spool that controls the tilt. Doesn't
leak until the lever is moved to change the tilt.

Bottom of spool has a cover on it. Took the cover
off and it exposed the spring on the bottom of the
piston that moves up and down to direct the fluid to
change the tilt.

Again, I hope I have used the correct terminology to
describe my problem.

Thanks again.

AJ. · Sep 19, 2017

The terminology is fine,the oil has no pressure on it till the lever is moved.the cap that covers the spring should not fill up with oil,if its filling the o'ring on the bottom of the spool (piston) is leaking,the spool has to be removed to access the o'ring which is in a groove in the spool bore,one at the bottom and one at the top about a 1/4" up from the bottom and 1/4 down,you sure the shop changed the bottom one,were they thinking there was no need to because of the cover,if there is nothing under the valve you may be able to take it out by removing the cap from the bottom and the lever from the top the spool will slip straight down,if there is no room to get it out that way you can take the spring off the bottom of the spool and then it will go up,you would only need to get it up an inch to clear the o'ring so you can replace it.
AJ

Case 850D Dozer blade hydraulics

Old Bob

Member

AJ.

Well-known Member

Old Bob

Member

AJ.

Well-known Member

Similar threads