HST filter

   / HST filter #1  

Mike H

Silver Member
Joined
Apr 6, 2000
Messages
120
Location
SW MI
Tractor
TC33D 7308 loader 757C backhoe
First a caveat: I'm an engineer and can't evade failure analysis.

When I did my 50 hr maintenance recently (TC33), the HST filter looked funny to me. It was raining today so I finally got around to cutting it open and looking at it. The filter element was buckled. The metal center cylinder was dented in radially about 3/8". My first and second reactions were "oh !%$@#!". But I really don't think this buckled hydraulically. The paper element is almost perfectly clean, there are no tears, and there's no damage to the elastomeric seal (so there was no pressure release rupture). As I studied it some more, the only explanation I could come up with is that it was mechanically damaged prior to assembly. It looks like crap but functionally, it would work fine. I know that in my job daily I'm called on to evaluate discrepant parts and if they won't hurt functionally, we ship 'em.

Thoughts? Anybody seen anything like this beforel
 
   / HST filter #2  
A tree limb will also cause the metal to buckle. They just don't make the canisters heavy enough./w3tcompact/icons/smile.gif
But the inner canister well thats something that I can't answer.
Gordon
 
   / HST filter #3  
Have not seen this before. I've had the outside shell blow on a truck when the engine block bypass stuck. This was a cold start and no relief. Blamo! /w3tcompact/icons/shocked.gif You never saw 6 quarts hit the ground quicker.
If the filter was still functioning, consider yourself lucky you did not find metal or dirt traces that may be in the works. I've heard this nightmare on another groups post. I do always check any new ones I might be installing.
I would imagine the HST filters would have a stronger case for the higher pressures involved.

"What is a weed? A plant whose virtues have not yet been discovered."
Ralph Waldo Emerson (1803-1882)
 
 
Top