Getting Oil into the TB Tensioner
06-03-2010, 12:11 AM
#16
Team Owner
since this link was posted I will add a few thoughts
First i would suggest that you do NOT go near the tensioner with any compressed air.
Second I would also suggest that you use a visene bottle with the tip drilled out with a 1/8 drill bit.
Dont use the oil pump can
Third, I suggest to use STP oil treatment to fill the tensioner.
Fourth, when filling the tensioner you fill from the hole thats the closest to the right side of the car.
Remove both of the bleeder nipples or port plugs whatever you have..
Heres why...
the tensioner boot is secured with 2 clamps, one inside and one outside.
When you rebuild your tensioner you want the open end of the inner clamp to face up, this puts the maximum amount of clamp in the oil level area.
The inside clamp is not as strong as the outer boot clamp and if any type of pressure is built up inside the tensioner it is quite possible to blow the boot clamp off the inner sealing surface , this will release a good bit of oil that can then contaminate your belt and rollers. The oil pump can will do the same thing.
If both of the bleeders are removed then there wont be any obstructions to the outlet ( the hole closest to the crank).
If you do blow off the inner clamp then you have to take the tensioner apart to fix this issue, that means belt removal.
Using the visene bottle does 2 things,
one it is very hard to add much pressure to the tensioner housing.
And the visene bottle tip fits neatly into the port and doesnt leak when it is being filled .
The reason to use the STP oil treatment is to delay the possibility of a leaking tensioner for some reason, ( my guess is because of its viscosity)this oil takes a very long time to leak past the gasket seals and the boot.
If you are having problems filling with the visene bottle then try back filling in the other port this may take a few mins for the oil to flow .
You can also replace your exisiting oil with the STP by simply filling slowly , place a rag under the outlet port and the STP will force the old oil out as its heavier so it sinks to a lower level eventually you will see the old oil being forced out of the port.
If you follow these suggestions you shouldnt have any issues with your tensioner.
These suggestions have been gleaned from experience YMMV
First i would suggest that you do NOT go near the tensioner with any compressed air.
Second I would also suggest that you use a visene bottle with the tip drilled out with a 1/8 drill bit.
Dont use the oil pump can
Third, I suggest to use STP oil treatment to fill the tensioner.
Fourth, when filling the tensioner you fill from the hole thats the closest to the right side of the car.
Remove both of the bleeder nipples or port plugs whatever you have..
Heres why...
the tensioner boot is secured with 2 clamps, one inside and one outside.
When you rebuild your tensioner you want the open end of the inner clamp to face up, this puts the maximum amount of clamp in the oil level area.
The inside clamp is not as strong as the outer boot clamp and if any type of pressure is built up inside the tensioner it is quite possible to blow the boot clamp off the inner sealing surface , this will release a good bit of oil that can then contaminate your belt and rollers. The oil pump can will do the same thing.
If both of the bleeders are removed then there wont be any obstructions to the outlet ( the hole closest to the crank).
If you do blow off the inner clamp then you have to take the tensioner apart to fix this issue, that means belt removal.
Using the visene bottle does 2 things,
one it is very hard to add much pressure to the tensioner housing.
And the visene bottle tip fits neatly into the port and doesnt leak when it is being filled .
The reason to use the STP oil treatment is to delay the possibility of a leaking tensioner for some reason, ( my guess is because of its viscosity)this oil takes a very long time to leak past the gasket seals and the boot.
If you are having problems filling with the visene bottle then try back filling in the other port this may take a few mins for the oil to flow .
You can also replace your exisiting oil with the STP by simply filling slowly , place a rag under the outlet port and the STP will force the old oil out as its heavier so it sinks to a lower level eventually you will see the old oil being forced out of the port.
If you follow these suggestions you shouldnt have any issues with your tensioner.
These suggestions have been gleaned from experience YMMV
06-03-2010, 12:37 AM
#17
When I changed the TB a few months ago it was a bitch to force fluid in the tensioner. After a day or all the fluid leaked out. About a month ago I rebuild the tensioner again and this time I removed the nipples and I noticed some blockage in the opening so I used a air gun to clean them out. The filling of the tensioner was pretty easy this time and it has not leaked out yet.
06-03-2010, 01:01 AM
#18
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Stan,
I guess you miss read the post. The point was to blow out all the holes in the tensioner while it was removed from the car - not while it was in position on the car.
I do this everytime I rebuild a tensioner - not very often these days because I only use a PKensioner.
Very important to blow out all the passages on the tensioner and compressed air is the perfect meduim.
Then the oil will flow much easier using what ever method floats your boat.
Interesting about using STP. I wonder what the heat transfer qualities of the thicker oil are. Would that not further reduce the effectivness of the bellville washers to detension the belt?
Roger
I guess you miss read the post. The point was to blow out all the holes in the tensioner while it was removed from the car - not while it was in position on the car.
I do this everytime I rebuild a tensioner - not very often these days because I only use a PKensioner.
Very important to blow out all the passages on the tensioner and compressed air is the perfect meduim.
Then the oil will flow much easier using what ever method floats your boat.
Interesting about using STP. I wonder what the heat transfer qualities of the thicker oil are. Would that not further reduce the effectivness of the bellville washers to detension the belt?
Roger
__________________
Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission?
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Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission?
George Layton March 2014928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
06-03-2010, 01:54 AM
#19
Rennlist Member
The oil does not "Dampen". I guess if the washers are wet with oil, they would be damp. 
The oil does not act as a damper fluild, as it in no way can have the viscosity to damp the osciliations. However, It does reduce the chance of the metal discs getting corroded. the main purpose is for heat transfer. Ive been running a system for 10 years with no oil in it, with no issues at all. there is some residual oil in there, but most has leaked out.
mk
The oil does not act as a damper fluild, as it in no way can have the viscosity to damp the osciliations. However, It does reduce the chance of the metal discs getting corroded. the main purpose is for heat transfer. Ive been running a system for 10 years with no oil in it, with no issues at all. there is some residual oil in there, but most has leaked out. mk
06-03-2010, 01:57 AM
#20
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edit...now that i read the rest of the posts. Sorry to drive the point home.
06-03-2010, 02:02 AM
#21
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since this link was posted I will add a few thoughts
First i would suggest that you do NOT go near the tensioner with any compressed air.
Second I would also suggest that you use a visene bottle with the tip drilled out with a 1/8 drill bit.
Dont use the oil pump can
Third, I suggest to use STP oil treatment to fill the tensioner.
Fourth, when filling the tensioner you fill from the hole thats the closest to the right side of the car.
Remove both of the bleeder nipples or port plugs whatever you have..
Heres why...
the tensioner boot is secured with 2 clamps, one inside and one outside.
When you rebuild your tensioner you want the open end of the inner clamp to face up, this puts the maximum amount of clamp in the oil level area.
The inside clamp is not as strong as the outer boot clamp and if any type of pressure is built up inside the tensioner it is quite possible to blow the boot clamp off the inner sealing surface , this will release a good bit of oil that can then contaminate your belt and rollers. The oil pump can will do the same thing.
If both of the bleeders are removed then there wont be any obstructions to the outlet ( the hole closest to the crank).
If you do blow off the inner clamp then you have to take the tensioner apart to fix this issue, that means belt removal.
Using the visene bottle does 2 things,
one it is very hard to add much pressure to the tensioner housing.
And the visene bottle tip fits neatly into the port and doesnt leak when it is being filled .
The reason to use the STP oil treatment is to delay the possibility of a leaking tensioner for some reason, ( my guess is because of its viscosity)this oil takes a very long time to leak past the gasket seals and the boot.
If you are having problems filling with the visene bottle then try back filling in the other port this may take a few mins for the oil to flow .
You can also replace your exisiting oil with the STP by simply filling slowly , place a rag under the outlet port and the STP will force the old oil out as its heavier so it sinks to a lower level eventually you will see the old oil being forced out of the port.
If you follow these suggestions you shouldnt have any issues with your tensioner.
These suggestions have been gleaned from experience YMMV
First i would suggest that you do NOT go near the tensioner with any compressed air.
Second I would also suggest that you use a visene bottle with the tip drilled out with a 1/8 drill bit.
Dont use the oil pump can
Third, I suggest to use STP oil treatment to fill the tensioner.
Fourth, when filling the tensioner you fill from the hole thats the closest to the right side of the car.
Remove both of the bleeder nipples or port plugs whatever you have..
Heres why...
the tensioner boot is secured with 2 clamps, one inside and one outside.
When you rebuild your tensioner you want the open end of the inner clamp to face up, this puts the maximum amount of clamp in the oil level area.
The inside clamp is not as strong as the outer boot clamp and if any type of pressure is built up inside the tensioner it is quite possible to blow the boot clamp off the inner sealing surface , this will release a good bit of oil that can then contaminate your belt and rollers. The oil pump can will do the same thing.
If both of the bleeders are removed then there wont be any obstructions to the outlet ( the hole closest to the crank).
If you do blow off the inner clamp then you have to take the tensioner apart to fix this issue, that means belt removal.
Using the visene bottle does 2 things,
one it is very hard to add much pressure to the tensioner housing.
And the visene bottle tip fits neatly into the port and doesnt leak when it is being filled .
The reason to use the STP oil treatment is to delay the possibility of a leaking tensioner for some reason, ( my guess is because of its viscosity)this oil takes a very long time to leak past the gasket seals and the boot.
If you are having problems filling with the visene bottle then try back filling in the other port this may take a few mins for the oil to flow .
You can also replace your exisiting oil with the STP by simply filling slowly , place a rag under the outlet port and the STP will force the old oil out as its heavier so it sinks to a lower level eventually you will see the old oil being forced out of the port.
If you follow these suggestions you shouldnt have any issues with your tensioner.
These suggestions have been gleaned from experience YMMV
Stan,
I guess you miss read the post. The point was to blow out all the holes in the tensioner while it was removed from the car - not while it was in position on the car.
I do this everytime I rebuild a tensioner - not very often these days because I only use a PKensioner.
Very important to blow out all the passages on the tensioner and compressed air is the perfect meduim.
Then the oil will flow much easier using what ever method floats your boat.
Interesting about using STP. I wonder what the heat transfer qualities of the thicker oil are. Would that not further reduce the effectivness of the bellville washers to detension the belt?
Roger
I guess you miss read the post. The point was to blow out all the holes in the tensioner while it was removed from the car - not while it was in position on the car.
I do this everytime I rebuild a tensioner - not very often these days because I only use a PKensioner.
Very important to blow out all the passages on the tensioner and compressed air is the perfect meduim.
Then the oil will flow much easier using what ever method floats your boat.
Interesting about using STP. I wonder what the heat transfer qualities of the thicker oil are. Would that not further reduce the effectivness of the bellville washers to detension the belt?
Roger
06-03-2010, 02:32 AM
#22
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Mark:
In 1983 the tensioner design was changed to include a "dampening" function wherein a valve inside an o-ringed carrier was added behind the washer stack provide vibration dampening. So, the oil is for heat transfer to the bimetal washers, as in the earlier tensioner, but adds a dampening function as well. it is shown in the WSM and described in the 1983 service info.
In 1983 the tensioner design was changed to include a "dampening" function wherein a valve inside an o-ringed carrier was added behind the washer stack provide vibration dampening. So, the oil is for heat transfer to the bimetal washers, as in the earlier tensioner, but adds a dampening function as well. it is shown in the WSM and described in the 1983 service info.
06-03-2010, 05:08 AM
#23
Team Owner
Roger, Roger, using compressed air when the tensioner is taken apart, sorry i misread that portion of your post.
In that case it would be a good idea to clean out the passageways,
but not once the tensioner is assembled
In that case it would be a good idea to clean out the passageways,
but not once the tensioner is assembled
06-03-2010, 02:50 PM
#26
Rennlist Member
No fill holes in my '78. When were they added?
06-03-2010, 02:52 PM
#27
Rennlist Member
Thanks Bill. cool info. I dont think I have seen that print out of the system.
I think that the fluid could provide some damping, but probably as a fluid stop, more than a damper, as in the definition of damping. How much does the system move, how much fuid can move through that little hole. Its not like a oil filled shock, but I do see the idea. I just dont think there is much movement anyway, especially how incredibly stiff the wavey washers are in their stack. anyway, I still think the oil is mainly for heat transfer, and this damping fluff is just that. Unless there is someway to see the vibrations or show that the compressed washers can move more than a small fraction of an inch under extreme vibrations.
I think that the fluid could provide some damping, but probably as a fluid stop, more than a damper, as in the definition of damping. How much does the system move, how much fuid can move through that little hole. Its not like a oil filled shock, but I do see the idea. I just dont think there is much movement anyway, especially how incredibly stiff the wavey washers are in their stack. anyway, I still think the oil is mainly for heat transfer, and this damping fluff is just that. Unless there is someway to see the vibrations or show that the compressed washers can move more than a small fraction of an inch under extreme vibrations.
06-03-2010, 04:12 PM
#28
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06-03-2010, 04:42 PM
#29
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I got it guys, uhh, sometime ago. Heat transfer is primary function. Original point I was trying to make is about hydraulics.