› Pro-line Ultra Reservoir Shock Caps for Traxxas X-maxx
Real reservoir tech comes to RC’S mightiest monster truck
Regular readers will recall that we reviewed Pro-line’s eye-popping Ultra Reservoir Shocks for scale trucks back in the April 2017 issue, and found the reservoir tech to be as functional as it is stylish. Since then, the Pro-line CNC machines haven’t slowed down, and now there’s a second member of the Ultra Reservoir family: the super-sized cans you see here, for the Traxxas X-maxx. Unlike the Ultra Reservoir Shocks we reviewed back in April, which are complete dampers with springs, the Ultra Reservoirs for X-maxx include only the caps and reservoirs; the bodies, springs, rod ends, spring perches, and preload collars are carried over from your X-maxx’s stock shocks. Here’s how everything goes together, and what to expect when you hit the dirt.
Pro-line dry-fits the reservoirs to the caps for packaging, but you’ll need to disassemble them to install the O-rings and reservoir internals. If you fill the shocks the way Pro-line recommends in the Youtube video detailing the assembly, you’ll also need to remove the X-maxx shocks’ seal cartridges. You can reuse the oil in the X-maxx shocks if it’s still fresh, but you’ll need to add more oil to fill the reservoirs. For the best build, I recommend using all-new oil. I also suggest lubricating the O-rings on the caps, reservoir pistons, and bleed screws with seal grease such as Pro-tek R/C Premium Blue for the best performance. The machined parts fit as precisely as you’d expect, and between the printed instructions and Pro-line’s assembly video, you should be able to breeze through building and filling the shocks. Depending on the position of the reservoir piston, the shocks can be assembled for maximum reservoir capacity or minimum internal pressure. Reduced internal pressure is easier on the shock seals, so that’s how I built my shocks. The final step is reinstalling the shocks on the truck. Pro-line supplies machined Delrin pivot balls and washers to fit the caps, and the reservoir-equipped shocks simply bolt into place like the stockers.
The caps and reservoirs are threaded together in the package, but you’ll need to take them apart to install the internal bits.