Air pump belt bypass question
10-18-2002, 03:35 PM
#4
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I bet you bent it at the demolition derby last week 
I have heard putting 19 up to 21 on there. I just think it depends on which car and what the belt ended up like when it was done. I ordered one today, but don't know how it will fit. I will let you know. I guess if yours was a bent 19", and you rotated it 180 degrees, it would hold a bigger belt when you put it on. That is not the case.
I have heard putting 19 up to 21 on there. I just think it depends on which car and what the belt ended up like when it was done. I ordered one today, but don't know how it will fit. I will let you know. I guess if yours was a bent 19", and you rotated it 180 degrees, it would hold a bigger belt when you put it on. That is not the case.
10-19-2002, 01:50 AM
#5
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There are two different size fan pulleys - the standard one that is on most cars, and a slightly larger one that was optionally installed on cars destined for hot climates.
The 21" belt fits most cars.
The 21" belt fits most cars.
10-20-2002, 12:02 AM
#6
Mabey I am not looking at the setup correctly, but on my 81' it looks like the belt tension is adjusted by the air pump. If you bypass the air pump, does the belt only run from the crank pully to the fan pully? If that is the case how do you tension the belt? I didn't see any adjustment on my fan mounting bracket. Please advise me as I would like to by pass my air pump also. Just to clarify, doesn't the air pump inject air into the catalytic converter? Is it harmful to the system to bypass the pump? 
10-20-2002, 12:10 AM
#7
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Hi Sharks:
Car Quest stores can get belts next day or same day. For my 86 model, the 20" version works perfectly for air pump elimination. Specifically: Belt 6820, 1/2" x 20", 12.5/13mm x 510mm, cost $9. They let me take the 21" belt home to try while the 20" was on order. They even ordered a 19" just in case the 20” did not work. They let me exchange belts at no extra charge. I have read and heard that the 21” works for some models, but cannot confirm that. I did not need long bolts to do the job. The fan bracket bolted back up very easily, and created tension on the belt as it became tighter.
Now, who knows the specs for the BEARINGS/rollers for the smog pump??? There are needle bearings on one end. I have not dismantled the pump completely to reveal the pulley end bearings. It looks like I just whack the shaft to drive it back through the bearing from the pulley side toward the inside of the pump. Has anyone done this? Does the pulley side use needle or ball bearings? Can I order the bearings over the internet? How do I pull doughnut shaped bearings such as these? I do not have access to the back side to tap them out.
Any answers would be helpful.
Car Quest stores can get belts next day or same day. For my 86 model, the 20" version works perfectly for air pump elimination. Specifically: Belt 6820, 1/2" x 20", 12.5/13mm x 510mm, cost $9. They let me take the 21" belt home to try while the 20" was on order. They even ordered a 19" just in case the 20” did not work. They let me exchange belts at no extra charge. I have read and heard that the 21” works for some models, but cannot confirm that. I did not need long bolts to do the job. The fan bracket bolted back up very easily, and created tension on the belt as it became tighter.
Now, who knows the specs for the BEARINGS/rollers for the smog pump??? There are needle bearings on one end. I have not dismantled the pump completely to reveal the pulley end bearings. It looks like I just whack the shaft to drive it back through the bearing from the pulley side toward the inside of the pump. Has anyone done this? Does the pulley side use needle or ball bearings? Can I order the bearings over the internet? How do I pull doughnut shaped bearings such as these? I do not have access to the back side to tap them out.
Any answers would be helpful.
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10-20-2002, 01:30 PM
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Jim:
It's my understanding that the air pump aids converter light-off, and that it is recommended to leave it active if the cats are in place. Not a concern for me
There is no tension adjustment once the air pump is gone unless you find a Euro tensioner, which fits where the air pump used to be. 928 Int'l lists them available used, although they have not had them when I have ordered. The length of the replacement belt is, therefore, rather important, as is monitoring it frequently as it will stretch.
It's my understanding that the air pump aids converter light-off, and that it is recommended to leave it active if the cats are in place. Not a concern for me
There is no tension adjustment once the air pump is gone unless you find a Euro tensioner, which fits where the air pump used to be. 928 Int'l lists them available used, although they have not had them when I have ordered. The length of the replacement belt is, therefore, rather important, as is monitoring it frequently as it will stretch.
