The most common reason a jack will retract partially and stop, is the jack piston is bent. The bend can be hard to see, yet keep the jack from completely retracting. Jacks can be bent numerous ways that can include:
- Moving the coach with jack(s) extended.
- Not visually verifying each jack is completely retracted before releasing parking brake.
- Parking on too much of an incline. Side loads can be induced on the jacks.
- Jack has sunk into the ground.
- Use caution when blocks are used under jack pads. If the blocks are under jack pads ensure they will not break, or are not already broken. If a block breaks it can put side loads on the jack or impact loads that can bend the jack piston, jack mount, or jack pad.
If you find that the jacks manual retract valve is open, yet the jack still will not retract without assistance (prying it up, or using the weight of the coach). The jack piston is bent and MUST be replaced.
Here is a link to the RVA jack replacement cylinders.