Hydraulic Cylinder Repair Tips
An increasing amount of equipment owners are handling hydraulic cylinder repairs themselves to save time and money largely due in fact to the relatively simple procedure. Whether you are a seasoned pro at hydraulic cylinder repair or you could use a few pointers, these helpful tips can get you back on the job-site in no time.
Visual Inspection and Disassembly
External leaking is the usually the first sign that the cylinder needs to be inspected and/or repaired. Once you begin disassembly, be careful to keep the piston rod clean & free of contaminants.
Be sure to protect all threads from damage. This is crucial as it could lead to a costly replacement!
Taking a picture of the parts in their correct order for future reference will be a huge time saver for you when you reassemble!
Inspect all seals for damage or excessive wear. A pitted or grooved barrel may be the culprit if a piston seal shows these signs of damage and will need to be replaced.
A damaged rod seal could point to a wear band/guide bushing that is excessively worn or even a bent or scored rod. Both issues can culminate in the weight of the rod distressing the seal which will cause failure.
Dye penetrant spray can be used to identify cracks on the surface of the rod. Be sure to spray at all points where the diameter differs.
Inspect the chrome for dull spots. This could indicate a bend in the rod. In most cases, bent rods can be repaired in a press; however if the chrome is compromised, the rod must be re-chromed or replaced.
Be sure to look for pitting and scoring of the chrome surface as this could reduce the life of the rod seals. If the degree of the pitting and/or scoring is too high, the rod will need to be re-chromed or replaced.
When a wear band is fitted between the rod and head, it should be replaced during a cylinder repair due to high load wear. When the rod is supported directly on the head, a micrometer should be used to measure the internal diameter of the head in two positions, 90°apart, to validate the proper circular shape.
Minimal scoring on the lands of the seal groove is not detrimental to the functionality of the cylinder so long as the maximum diameter of the scoring doesn't exceed the nominal rod diameter plus .016",(depending upon pressure).
Barrel & Piston Examination
Pitting or scoring of the barrel will significantly impact the life of the piston seal. Honing the barrel to remove damage or replacement of the barrel is recommended if the scoring or pitting is too deep.
Slight scoring of the outside diameter of the piston will not impact cylinder function if the minimum diameter of the piston is not less than the nominal bore diameter minus .006".
Piston wear bands should always be replaced during the repair on cylinders where there are high loads on the rod.
Reassembly & Ordering Tips
S - SPEED at which your cylinder is designed to operate
T - TEMPERATURE range your operating system can expect
A - APPLICATION of the cylinder & its intrinsic value to the system
M - MEDIA (oil) type used in your system
P - PRESSURE range of your OS
S - SIZE of the cylinder (rod & bore) and its ancillary components
John Deere Replacement Piston Seal Kit - Order Now
Ford Replacement Seal Kit - Order Now
Commercial Replacement Reeving Cylinder Kit - Order Now
Rod Seal Installation Tool - Order Now
O-Ring Extraction Tool Set - Order Now