# HST Piping leak



## maxreco (Sep 30, 2015)

My 1620 has developed a leak in the where the pipe from the filter goes into the case, as shown in the picture. The pipe is held in place by an external clamp. The parts diagram doesn't show a banjo bolt. It calls for a P16 o-ring, which I have. I guess it failed due to age because nothing hit it, and the connection is tight.

I have some questions before I loosen that clamp. I know I need to drain the fluid; 

Is the drain plug that is below the HST sufficient, or do I have to also drain the plugs that are under the transmission?

Can I replace the o-ring by removing the pipe from the outside? In other words, without splitting the tractor?

I also have developed some dripping from the weep hole cotter pin. Could this be related to the piping leak, or does it indicate a leaking transmission seal? Both leaks began at the same time. 

Thanks to the group for any help!


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## RC Wells (Dec 26, 2008)

Drain the fluid below the level of the pipe, remove the bracket that holds it into the adapter, remove the banjo bolt on the upper end of the pipe, then unplug the pipe from the adapter. It will drool hydraulic fluid, so be prepared.

I presumed you have a picture of the parts list for that assembly, if not it is here: https://partstore.agriculture.newholland.com/us/parts-search.html#epc::mr64457ar323631

The internal leak is the banjo bolt seals on the adapter inside the housing. What has happened is one of two things. Either the mounting bolt (part #44) has worked loose and the adapter (part #46) has vibrated around enough to walk out the O rings on the internal banjo bolt (part #45) and on the pipe (part #12). Or, the O rings simply failed over time.

I suspect the former. When you go inside to repair the problem, clean the threads on the mounting bolt and in the casting, then use LocTite to keep it from loosening in the future.


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