PosiTech® International manufactures, remanufactures and rebuilds shell and tube bundle oil coolers for applications such as Caterpillar, Fiat-Allis, Detroit Diesel, Terex, Komatsu, Cummins, International, Mack, Ford, John Deere, Hyster, Michigan, and others. Shell and tube bundle oil coolers are available for torque converter, brake, engine, transmission, hydraulic, retarder, and other applications. PosiTech® International has the capacity to manufacture or service almost any style oil cooler.
Pictured above: (left) PC# 1033, (top right) PC# 1025, (bottom right) PC# 1008
Our rebuilt and remanufactured oil coolers can save our customers 70% off the cost of new, while offering our customers a more inclusive warranty than new. In effect, we take all the direct cost risk and you get 70% savings.
We use a high tech, specially designed process and one of a kind equipment to assure our customer of the highest quality.
A unit is received and identified. If the unit is sent from a customer we compare the packing list to what was actually received - any differences are noted and sent to the customer for verification. Units are stamped with a customer location and serial number.
The unit is then sent through a multi-step pre-cleaning process. The process includes specially formulated chemicals, detergents, soaks and flushes. The pre-cleaning process is intended to remove all oil, grease, and heavy contaminates. All units are then sent to disassemble the bundle from the housing. Given the dissimilar metals, we use a specially designed induction machine to ensure the even expansion and contraction of the bundle to housing.
IMPORTANT - Not being able to uniformly expand the unit causes a slight deformation of the bundle to housing unit. Braze requirements call for joint clearance of .003" to .005" for maximum braze strength. Non-uniform methods of removing the bundle from the housing will result in less than optimal clearances upon the reassembly of the unit. This can lead to field failures.
Next we bake all housings to remove any impregnated oil within the housing.
IMPORTANT - failure to remove the impregnated oil will weaken the braze joints upon reassembly of the unit. This can lead to field failures.
Bundles are then checked by our in-house check list to see if the bundle is a candidate for rebuilding. One of our checks is testing of the tube wall by our eddy current machine. This machine quantify us how much of the original tube wall has been removed and how much remains. Anyone can tell if there is a hole in a tube with a simple air under water leak test. We can tell if a tube which originally had .016 tube wall is now down to .005, .009 or .011 of the tube wall remaining.
If less than 20% of the tubes fail under our specification for minimum tube wall for a given unit, we will replace the defective tube(s) and the re-flow of the header. Next we will verify all baffles are in their proper location for the given part number. Last, we anchor baffles to tubes to significantly reduce the number one cause of bundle failure - a wearing of the tube by the baffle.
If the bundle is not able to be re-built, we build a new bundle. We can customize a tube pattern, baffle size, baffle position, to match any pattern by any OEM. Most OEMs call for tube wall specs from .012" to .018". All PosiTech® bundles are built with .018" tubes.
IMPORTANT - The braze used on your bundle makes a difference. Over the years some competitors have been supplying bundles brazed with Sil-phos. The advantage is that sil-phos is about 1/3 the cost of silver braze. In the correct end use application, Sil-phos is perfectly acceptable. But if the end use application uses engine oil or transmission fluid, the phosphorous in the Sil-phos will react and cause a chemical erosion of the copper tubes. All PosiTech® bundles are brazed with silver braze to allow for any end use application.
Rebuilt bundles are sent through a series of cleaning steps using specialized equipment that ensures all contamination is removed. Housings are inspected for overall length gasket seal flatness, and bolt holes are torqued to OEM specifications.
Bundles and housings are reassembled using an induction machine to again assure our customers of the highest strength - and quality - possible.
All units are then run through a series of cleaning processes, flushes , and multiple leak tests under conditions that simulate the entire work cycle of the unit. All serial numbers are recorded - the file includes the name of each operator who performed any function on the unit, batch numbers of all the component materials and dates of each step. Units are then painted and sprayed with a protective coating.
Remanufactured vs. Rebuilt
PosiTech® defines a remanufactured item as one where we replace a major component with new, while still using part of the original unit. In the case of shell and bundle oil coolers we define a remanufactured unit as one in which we replace and build a new tube bundle and use the original housing.
A rebuilt item is one where we replace less than 20% of the original unit with new. In the case of a shell and bundle oil cooler, a rebuilt unit is one where we are able to reuse both the original bundle and casting, but may replace up to 20% of the tubes with new and still define the unit as rebuilt.
Learn about the most Common
Oil Cooler Failures