TC45DA HST filter installation 3/4 turn or 1 and 1/4 turn

[flyingj]

I just changed the hydraulic and hst filters at 50 hours. The owners manual says to turn the hydraulic filter 3/4 turn after gasket contacts base. It says To change the H.S.T. system oil filter, 2, follow the procedures found above for changing the hydraulic system oil filter However, on the side of the replacement (and original) HST filter it says turn 1 and 1/4 turns after contact. Even with a wrench, I was only able to turn it 1 and 1/8 turn.

Anybody know which instruction is correct?

Jim Frisby
Palmer, Alaska

 

[RickB]

Always defer to the instructions on the actual filter you are installing. Also use a little descretion when necessary. If 1-1/8 turns makes the filter TIGHT, call it good and be happy. No need of risking damage to the filter or filter head.

 

[jinman]

Jim, that HST filter is under a lot of pressure. It is on the pressure side of the HST charge pump. The main hydraulic filter is a suction filter and under nothing but negative pressure as oil is drawn through it out of the reservoir. That's why the HST filter needs to be tighter.

As RickB said, don't overtighten if 1-1/8 turns seems to do the trick. Many forum members have struggled to remove an overtightened filter when the next service period comes.