Cat Brakesaver

How many out there? Can anyone share there experiences - problems with them? I'm wondering if the springs that hold the spool closed give trouble.

 

Reason I ask is I know of a truck that is Realy bad on fuel and runs hot, it has a brakesaver fitted but it is miles away from me and I can't get to it to check it out , I'm thinking if the springs have lost there tension or broken then oil could be slightly pushing past the spool and brakesaver could be dragging, anyone ever seen this ? There is a spec for spring length compressed and non compressed so I guess it is possible, I'm trying to diagnose this guys problems over the phone from the other end of the country, Not an easy task

 

Thanks king Q I've been trying to explain my theory to him, hopefully he takes it some where to get the springs checked out soon,

The brakesaver is not that common worldwide I've seen people ask what they are on here, I will post some info about them soon ,

anyone else have any experience with them ?

 

Engine Hydraulic Retarders


The hydraulic brake retarders are a whole different animal. Engine hydraulic retarders are mounted on the engine. The Caterpillar Brake Saver is the most popular retarder in this class. This retarder operates on the torque converter principle.


In a normal torque converter, vanes on the input housing (which is attached to the engine crankshaft) transmit power through the fluid coupling to the output shaft vanes of the torque converter, which is connected to the input shaft of the transmission. The hydraulic retarder transmits power from the rotor vanes (which are attached to the engine crankshaft) to the retarder housing vanes (which are attached to the engine block or bellhousing). This produces a hydraulic drag which absorbs vehicle motion energy while activated.


To activate the hydraulic retarder, oil is pumped into the housing, and the housing vanes exert drag due to the swirling oil, upon the rotor vanes. To stop the retarder action, simply drain the chamber, which uncouples the two vanes.


The retarder oil pressure supply is delivered from a secondary section of the engine oil pump. The oil used for the retarder comes from the oil sump of the engine, which must therefore have a larger capacity. This section of the oil pump is entirely separate from the engine lubrication section of the oil pump. This oil pump pressure can be modulated before it reaches the retarder housing. More oil pressure in the retarder housing means more retarding action. Less oil pressure results in less retarding action. While the oil is pressurized within the retarder housing, it is constantly being circulated through the oil cooler and back into the oil sump. This is required to remove the heat generated by the retarder friction.


This retarder has a BrakeSaver control valve which regulates the retarder action once it is activated. This control valve in conjunction with a driver control handle, will set a specific retarder action. As the engine slows in RPM due to the retarding action, the BrakeSaver control valve automatically increases the oil pressure in the retarder housing, which keeps the braking action constant as the pumping action of the retarder vanes decreases.


The retarder control valve also provides a proportioning valve function. The driver control handle will set the retarder force desired, when in manual mode, but while in auto mode, the driver's release of both the throttle and the clutch pedal, will apply maximum retarder action automatically. The proportioning valve uses the larger of these two pressures to control the retarding action.


Sent from my iPhone

 

Correct question is how many that are checked are found to be weak? Possibly not holding the spool fully closed. And resulting in the brakesaver dragging , low power- bad fuel economy- and high oil- coolant temp?