Just Plain Jeff
04-12-2007, 07:49 AM
Roger had dropped me a note and wondered whether or not to replace the entire unit or not. Rather than simply being a parts swapper (bad), here's the way to diagnose whether the fix was easier and less expensive than the swap-out:
First, clean the complete unit from the top. You may have to carefully use brake cleaner as it gets greasy. Make sure your aux compressor is off and the engine is not running.
Then, carefully make a mark on the retaining nut and the shaft with a sharpie or scratch with a screwdriver. Note whether or not the housing is held in place by retaining springs. If it is, there are three. Once the nut is properly marked, release the retaining springs. Don't sweat the snapping sound when the retaining springs are released, as there is a bracket which holds them to the base housing.
For some reason, the retaining spring unit has a 16mm nut, the non-retaining spring unit uses an 18 mm nut.
From the mark, at about two full turns counterclockwise, you will see that there is a bit of oil oozing from the fitting. This is normal. Slowly turn the nut off. With a little twist, the housing will come off. Careful not to break the gasket as it is a bugger to replace. Once the housing is released, you'll see a spring activated seal, which should come off easily in your hand. Take that off as well, being careful not to touch it with your hands.
With a flashlight, look inside the opening to the main housing. It should be clean with no visible scars or marks.
Take your left hand behind the main housing and release the retaining pin on the shaft. It should just pop off with some pressure.
Then carefully and slowly move the rod in and out and you can see if it is working smoothly and evenly. Keep exercising the rod until it moves with ease. Some of the older units are sloppy and/or the rod does not function very well. Where the rod enters the rear main housing it often gets somewhat worn, but that doesn't matter so much as the activator inside is operational.
After a bit of movement, you should see that the piston on the inside of the main housing is pushing some oil. That's the way it should work. If it is doing that, then you are in good shape.
After all this, take a break, and relax.
Return the piston rod to the original position and replace the retaining pin on the main rod (in the fully withdrawn position). Carefully clean the spring (not touching the seal!) and the inside of the cover. These can get a little crud on them over time.
Ever so carefully replace the cover over the spring/seal assembly and hold it on as straight as you can.
Then put the nut back on the rod and tighten to the original mark.
Turn the aux compressor on and check for operation. I think you will be completely satisfied with the results. For the final test, start the engine if you can and watch the operation of the unit.
In 99% percent of the cases, there is no need to replace the unit, as frequent maintenance usually solves the problem and no parts are needed assuming proper attention to detail.
Hope this helps.
First, clean the complete unit from the top. You may have to carefully use brake cleaner as it gets greasy. Make sure your aux compressor is off and the engine is not running.
Then, carefully make a mark on the retaining nut and the shaft with a sharpie or scratch with a screwdriver. Note whether or not the housing is held in place by retaining springs. If it is, there are three. Once the nut is properly marked, release the retaining springs. Don't sweat the snapping sound when the retaining springs are released, as there is a bracket which holds them to the base housing.
For some reason, the retaining spring unit has a 16mm nut, the non-retaining spring unit uses an 18 mm nut.
From the mark, at about two full turns counterclockwise, you will see that there is a bit of oil oozing from the fitting. This is normal. Slowly turn the nut off. With a little twist, the housing will come off. Careful not to break the gasket as it is a bugger to replace. Once the housing is released, you'll see a spring activated seal, which should come off easily in your hand. Take that off as well, being careful not to touch it with your hands.
With a flashlight, look inside the opening to the main housing. It should be clean with no visible scars or marks.
Take your left hand behind the main housing and release the retaining pin on the shaft. It should just pop off with some pressure.
Then carefully and slowly move the rod in and out and you can see if it is working smoothly and evenly. Keep exercising the rod until it moves with ease. Some of the older units are sloppy and/or the rod does not function very well. Where the rod enters the rear main housing it often gets somewhat worn, but that doesn't matter so much as the activator inside is operational.
After a bit of movement, you should see that the piston on the inside of the main housing is pushing some oil. That's the way it should work. If it is doing that, then you are in good shape.
After all this, take a break, and relax.
Return the piston rod to the original position and replace the retaining pin on the main rod (in the fully withdrawn position). Carefully clean the spring (not touching the seal!) and the inside of the cover. These can get a little crud on them over time.
Ever so carefully replace the cover over the spring/seal assembly and hold it on as straight as you can.
Then put the nut back on the rod and tighten to the original mark.
Turn the aux compressor on and check for operation. I think you will be completely satisfied with the results. For the final test, start the engine if you can and watch the operation of the unit.
In 99% percent of the cases, there is no need to replace the unit, as frequent maintenance usually solves the problem and no parts are needed assuming proper attention to detail.
Hope this helps.